Control, sound, and operating system for model trains

Information

  • Patent Grant
  • 6457681
  • Patent Number
    6,457,681
  • Date Filed
    Thursday, December 7, 2000
    23 years ago
  • Date Issued
    Tuesday, October 1, 2002
    21 years ago
Abstract
A model train operating, sound and control system provides a user with increased operating realism. A novel remote control communication capability between the user and the model trains includes a handheld remote control on which various commands may be entered, and a Track Interface Unit that retrieves and processes the commands. The Track Interface Unit converts the commands to modulated signals (preferably spread spectrum signals) which are sent down the track rails. The model train picks up the modulated signals, retrieves the entered command, and executes it through use of a processor and associated control and driver circuitry. A speed control circuit located inside the model train is capable of continuously monitoring the operating speed of the train and making adjustments to a motor drive circuit. Circuitry is connected to the Track Interface Unit to an external source, such as a computer, CD player, or other sound source, so that real-time sounds stream down the model train tracks for playing through the speakers located in the model train. Coupler designs and circuits, as well as a smoke unit, can also be used with the model train system.
Description




FIELD OF THE INVENTION




The present invention is directed to a new control, sound and operating system for model toys and vehicles, and in particular for model train and railroad systems. The present invention contains a number of inventive features for model trains as well, including new coupler and smoke unit designs.




BACKGROUND OF THE INVENTION




Model trains have had a long and illustrious history. From the earliest model trains to the present, one of the primary goals of model train system designers has been to make the model train experience as realistic as possible for the user.




The typical model train has an electric motor inside the train that operates from a voltage source. The voltage is sent down the model tracks where it is picked up by the train's wheels and rollers, then transferred to the motor. A power source supplies the power to the tracks. The power source can control both the amount (amplitude) and polarity (direction) of the voltage, so that the user may control both the speed and direction of the train. Some systems use a DC voltage applied to the track. In others, the voltage is an AC voltage, and is usually the 60 Hz AC voltage available from standard U.S. wall outlets. In these systems, a transformer is necessary to reduce the amount of voltage provided to the system.




Using the above-described system, an early method of operating model trains is now referred to as “legacy” mode. As the user increases or decreases the amount of voltage applied to the track through manipulation of a throttle on the power source, the train will gain or lose speed as it travels along the track. This is a straightforward operation whereby the user directly controls the amount of voltage applied to the train's motor. Such a mode of operation requires the user to constantly monitor and adjust the amount of voltage applied to the tracks. For example, a train approaching a curve in the track may de-rail if the train is moving too fast. The user must therefore reduce the amount of voltage received by the train's motor by cutting back on the power source throttle prior to the train reaching the curve. Similar situations may occur elsewhere on the track layout, such as when the train approaches an upgrade (which may require the user to increase the amount of voltage applied) or when the train is attached to a heavy load.




In addition to being able to control the speed and direction of model trains, early train systems enabled the user to operate a whistle (or horn) and later a bell located on the train. In AC-powered systems, this was done by applying a DC offset voltage superimposed on the AC voltage applied to the track. In later systems, the train had circuitry that distinguished between the polarities of the DC offset voltage. Thus, for example, the whistle (or horn) would blow when a +DC offset voltage was applied to the track, and the bell would ring when a −DC offset voltage was applied. Typically, the user would press a “horn” or “bell” button located on the power source to effect the desired sound.




It should be apparent that the above-described system provided the user with only limited control over the operation of the train, and further required constant manual manipulation of the power source in order to maintain the train on the track layout. Later-developed'systems therefore attempted to address these shortcomings and thereby increase the realism of the model train experience.




Two examples of such systems include those disclosed in U.S. Pat. No. 5,251,856 to Young et al., and Marklin's Digital line of model trains. These systems enabled the user to have remote control operation of the train. This was accomplished by inserting a control unit between the power source and the tracks. The control unit responded to commands entered by the user on a hand-held remote control. These types of systems generally utilized microprocessor technology. A microprocessor or receiver located in the model trains would have a unique digital address associated with it. The user would enter the train's address and a command for the train on the remote control, such as “stop,” “blow whistle,” “change direction,” and so on. The address and commands would be implemented as infra-red (IR) or radio frequency (RF) signals. The control unit would receive the commands and pass the commands through the tracks in digital form, where the model train corresponding to the entered address would pick up the command. The microprocessor inside the model train would then execute the entered command. For example, if the user had entered a command such as “turn on train light,” the microprocessor would send a signal to the light driver circuit located inside the train, and the light driver circuit would turn on the light.




In the aforementioned U.S. Pat. No. 5,251,856, the user is able to control the speed of the train through the remote control. This is accomplished through the use of a triac switch located inside the control unit. The power source is set to a maximum desired level. In response to input from the user, the triac switch inside the control unit switches the AC waveform from the power source at appropriate times to control the AC power level and impose a DC offset. The speed of the trains will then change in accordance with the change in power applied to the track. The aforementioned Marklin system, on the other hand, controls the speed of the trains by use of pulse width modulation (PWM) and fullwave rectifier circuits located inside the train. The duty factor of the output signal from the PWM circuit varies between 0 and {fraction (15/16)} at a frequency that is {fraction (1/16)} of a counter frequency that remains constant. This allows the user a 16-step speed control for each train.




Many other advances have been made in model trains beyond those described here. For example, U.S. Pat. No. 4,914,431 to Severson et al. describes the use of a state machine in the train that increases the number of control signals available to the user for control over train features such as sound volume, couplers, directional state, and various sound features. U.S. Pat. No. 5,448,142 discloses, among other things, ways to improve the quality and realism of sounds made by the train during operation. Still, further advances in the area of model trains are desirable, in order to approach the desired goal of realism during operation.




SUMMARY OF THE INVENTION




The present invention provides a model train operating, sound and control system that provides a user with operating realism beyond that found in prior art systems. The present invention provides a number of new and useful features in order to achieve this goal.




One feature of the present invention is a novel two-way remote control communication capability between the user and the model trains. This feature is accomplished by using a handheld remote control on which various commands may be entered, and a Track Interface Unit that retrieves and processes the commands. The Track Interface Unit converts the commands to modulated signals (preferably spread spectrum signals) which are sent down the track rails. The model train picks up the modulated signals, retrieves the entered command, and executes it through use of a processor and associated control and driver circuitry. The process may also be reversed, so that operating information regarding the train is provided back to the user for display on the remote control.




Another feature of the present invention is a speed control circuit located on the printed circuit board inside the model train that is capable of continuously monitoring the operating speed of the train and making adjustments to a motor drive circuit. Through this circuit, precise and accurate scale miles-per-hour speed may be continuously maintained by the model train, even as the train goes up and down hills or around curves.




Still another feature of the present invention is the ability to connect the Track Interface Unit to an external source, such as a computer, CD player, or other sound source, and have real-time sounds stream down the model train tracks for playing through the speakers located in the model train. This feature enables a user to actually have a song or other recorded sound “played” by the model train as it travels around the tracks. A microphone embodiment is also disclosed, whereby the user's voice may be played out through the model train speakers in real time.




Another feature of the present invention is a new coupler design and circuit that enables the activation of electric couplers to be achieved at very low voltage. This feature allows coupler firing in the model train environment to more closely match the operating conditions of couplers on real trains. This is particularly important when operating in “legacy” mode, where low voltage is directly related to low speed, thereby providing more realistic operation.




Yet another feature of the present invention is a smoke unit circuit design that allows smoke (or steam) output to be controlled by the user. In this way, smoke and steam output from the model train can be synchronized to match the operating condition of the train. For example, as the train picks up speed, the amount of smoke or steam output would increase accordingly. Or, if the load on the train increases, a larger amount of smoke will be outputted indicative of the additional power required to move the train. In addition, the smoke puffs let out by the train can be synchronized with the rotation of the wheels and thereby reflect train speed. For example, the smoke unit circuit can be controlled so that each 1/4 rotation of the train wheels will result in one smoke “puff”. Also, the smoke unit circuit can be controlled to “stream” smoke continuously, even at zero velocity, as do real-life steamer-type trains. Even further, the volume of smoke output can be automatic in relation to train conditions, or it can be manually controlled by the user.




Many other features are described herein. For example, sounds may be synchronized to the model train operation, such as engine “chuff” sounds. The present invention provides the capability of the model train simulating the Doppler effect as the train approaches and passes by. A series of operating commands may be recorded by the user for precise play-back at another time. Customized sounds may be recorded so that users can have the model train play their own unique sounds. Sounds and information may be downloaded (and uploaded) through the Internet via a computer or information appliance hookup to the TIU (additional examples include telephones, PDAs, or other devices capable of providing information). Many different accessories (track lights, track;switches, crossing gates, etc.) may be controlled by the user on the remote control through use of an Accessory Interface Unit, also described herein.




The complete invention is described below, and in the corresponding claims.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

shows one exemplary embodiment of the basic elements of the control system of the present invention;





FIG. 2

shows one exemplary embodiment of the hand-held remote control of the present invention;





FIG. 3

shows one exemplary embodiment of the Track Interface Unit of the present invention;





FIG. 4

shows one exemplary embodiment of the printed circuit board located on the model train(s);





FIG. 4A

shows an alternative “analog” sound system;





FIG. 5

shows a prior art (“legacy”) speed control circuit;





FIG. 6

shows a graph indicating speed vs. voltage at different loads for the speed control circuit of

FIG. 5

;





FIG. 7

shows one exemplary embodiment of the speed control circuit of the present invention;





FIG. 8

shows one exemplary embodiment of the pulse width modulator circuit for the speed control circuit of

FIG. 7

of the present invention;





FIG. 9

shows a graph indicating speed vs. voltage of the present invention in comparison to the prior art graph of

FIG. 6

;





FIG. 10



a


shows a side view of a conventional mechanical coupler;





FIG. 10



b


shows a bottom view from

FIG. 10



a


of the latch member of the conventional mechanical coupler;





FIG. 11



a


shows two trains preparing to be coupled using the conventional mechanical coupler of

FIG. 10



a;







FIG. 11



b


shows interaction between the conventional mechanical couplers;





FIG. 11



c


shows the two conventional mechanical couplers in a locked closed position;





FIG. 12



a


shows the basic elements of a conventional solenoid coupler;





FIG. 12



b


shows the conventional solenoid coupler in an un-locked opened position;





FIG. 12



c


shows the conventional solenoid coupler in a locked closed position;





FIG. 13



a


shows the basic elements of an exemplary embodiment of the novel coupler of the present invention;





FIG. 13



b


shows the novel coupler of the present invention in the locked closed position;





FIG. 13



c


shows the novel coupler of the present invention in the un-locked open position;





FIG. 13



d


shows a portion of

FIG. 13



b


in enlarged detail;





FIG. 13



e


shows a portion of

FIG. 13



c


in enlarged detail;





FIG. 13



f


shows the magnetic flux lines produced in the conventional solenoid coupler;





FIG. 13



g


shows the magnetic flux lines produced in the novel coupler of the present invention;





FIG. 14



a


shows one exemplary embodiment of a smoke unit of the present invention;





FIG. 14



b


shows another exemplary embodiment of a smoke unit of the present invention;





FIG. 14



c


shows the control schematic for the smoke unit of the present invention;





FIG. 15



a


shows a logic diagram of a spread spectrum signal decoder in an ideal environment;





FIG. 15



b


shows a logic diagram of a spread spectrum signal decoder in a noisy operating environment;





FIGS. 16



a


-


16




d


show graphs of the Doppler effect simulations capable with the present invention;





FIG. 17



a


shows one exemplary embodiment of the Accessory Interface Unit of the present invention; and





FIG. 17



b


shows one exemplary embodiment of a plurality of Accessory Interface Units attached to the track layout.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




The present invention provides a control system that allows the user to operate multiple trains on the same track and under independent operating instructions. The present invention also allows a user to operate different trains on the same track in different modes of operation. For example, a user may operate one or more trains in “command” mode, which refers to the present invention's use of digital signals to operate the model train equipped with the inventive features described herein. At the same time, a user may operate one or more trains on the track in the aforementioned “legacy” mode. Finally, other trains on the track may operate in “conventional” mode, which is similar to legacy mode but which takes advantage of certain features of the present invention to improve the operation of the train.




OVERVIEW





FIG. 1

shows the basic components of the control system of the present invention. The track layout


10


is coupled to a Track Interface Unit (TIU)


12


, which in turn is coupled to an Accessory Interface Unit (AIU)


18


. The AIU is connected to any number of train layout accessories (shown generically as Accessories


18


′ in FIG.


1


). The TIU


12


is connected to a power source


14


, which may be any type of AC or DC voltage source, such as a transformer. In this embodiment, the power source


14


provides AC voltage and is plugged into a standard wall outlet (not shown). Also shown in

FIG. 1

is a hand-held remote control


16


. The user inputs commands on the remote control


16


in order to control the operation of the train(s)


11


on the track layout


10


. The command mode of operation will be explained next.




In command mode, the train(s)


11


on the track ignore the voltage that is applied to the tracks with respect to speed settings. Instead, the train(s)


11


respond only to digital speed command signals entered by the user. In command mode, therefore, the power source


14


is typically set to approximately maximum voltage and left there.




The user enters the desired commands on the remote control


16


. These commands are relayed to the TIU


12


by RF signals in the preferred embodiment, although it should be understood that any form of wireless transmission, including IR signaling, would also be acceptable. The TIU


12


has circuitry (explained more fully below) that receives the RF signals containing the commands, and other circuitry that converts the signals into modulated signals.




The present invention utilizes “spread spectrum” signaling as the preferred mode of communicating commands from the user to the model train(s)


11


. Other modulation types are also acceptable and considered to be within the scope of the present invention. Spread spectrum signalling, however, has been determined to be the preferred method. Generally, in spread spectrum signaling, the signal is coded and the bandwidth of the transmitted signal is made larger than the minimum bandwidth required to transmit the information being sent.




Spread spectrum signaling is desirable in the present context because model train layouts generally are a noisy operating environment. When a narrow bandwidth is used to transmit a signal, there is the possibility that, due to noise, fading, or other interference, and the signal will be lost. Spread spectrum signaling substantially eliminates this risk. The details of the spread spectrum signalling used in the present invention will be described in detail below.




For illustrative purposes, the rest of the description herein will refer to spread spectrum signalling when referring to the communication method employed. It is contemplated, however, that other modulation methods could also be used, as described above.




Returning to the description of the command mode of operation, the TIU


12


transmits the spread spectrum signals out over the track layout


10


. In other words, the signals are actually passed down the rail(s) of the track. The TIU


12


also provides power to the tracks from the power source


14


. Thus, both track power (in the form of AC voltage) and the commands are sent out by the TIU


12


to the track layout


10


through the track rail(s).




The train(s)


11


on the track layout


10


have an engine board inside that contains a microprocessor and other circuitry, as will be described below. In simplest terms, the engine board in the train(s)


11


will receive the spread spectrum signals from the TIU


12


and execute any commands addressed to it. The train(s)


11


then performs the command entered by the user.




In command mode, each model train


11


has a unique digital address associated with it (along with a “universal address” that, if inputted, would send the command to all the trains). The user enters the address on the remote control


16


and the command that the user desires that particular train


11


to perform. Only the train


11


whose address has been entered will respond to the command.




Through this arrangement, multiple trains


11


may be independently controlled and operated by the user through use of the remote control


16


. As a non-limiting example, a user may command train #


1


to accelerate to a desired speed and turn on its lights; command train #


2


to announce its impending arrival at the next station and to stop at that station; and command train #


3


to reverse direction, slow down and fire its coupler in order to prepare to connect to a box car consist. The present invention allows for all three trains


11


to execute their respective commands independently of each other, while a constant AC voltage is applied to the track. Two or more trains


11


can function on the same track, at different speeds, even though the track voltage is the same and is controlled by the single power source


14


via the TIU


12


.




Users can also operate one or more trains


11


on the track layout


10


in conventional mode. In this mode, the user varies the track voltage by manipulating the power source


14


( either manually or by remote control). A train


11


operating in conventional mode will respond to the change in track voltage by slowing down or speeding up. If more than one train


11


is operating in conventional mode, each will respond at the same time to the variance in track voltage being applied by the power source


14


. Thus, independent operation of trains


11


in conventional mode is not possible.




However, the present invention allows the user to have one or more trains


11


operating in command mode and one or more trains


11


operating in conventional mode on the same track layout


10


. Those train(s)


11


equipped with the novel engine board shown in

FIG. 4

will operate in command mode if the user so desires as described above in response to commands entered by the user on the remote control


16


. Those train(s)


11


operating in conventional mode will respond to changes in the track voltage effected by the user through the power source


14


. The train(s)


11


in command mode will continue to execute the commands entered by the user without regard for the change in track voltage (subject to operational limits), and the train(s)


11


in conventional mode will respond only to changes in track voltage, oblivious to the spread spectrum signals applied to the tracks for the command mode train(s)


11


. This allows older trains and trains of different manufacturers to operate alongside the inventive train disclosed herein on the same track layout.





FIG. 2

shows one embodiment of the remote control


16


in more detail. It should be understood that the embodiment shown in

FIG. 2

is merely exemplary, and any number of different remote control functions/designs may be used. In

FIG. 2

, the remote control


16


has an LCD display


160


, a thumb-wheel


161


, and various push buttons


162


. The user enters commands by pressing a particular push-button


162


(or a predetermined series of push-buttons


162


) dedicated to a particular command, or by using the thumb-wheel


161


to scroll through a menu that appears on the LCD display


160


to select the desired command. The remote control


16


is preferably battery operated and is controlled by a processor


163


. One acceptable processor


163


is part number M30624FGLFP sold by Mitsubishi. It should be understood that other processors or hard-wired circuitry could be used. The remote control


16


also has a wireless transmitter, such as the illustrated RF transceiver


164


and antenna


165


. The processor


163


in the remote control


16


monitors the inputs from the user and from the RF antenna


165


for any changes and updates the display accordingly.




As previously stated, the remote control


16


communicates with the TIU


12


as shown in FIG.


1


. When the remote control processor


163


is required to send a command to the TIU


12


, it does so through the RF transceiver


164


. In one embodiment, the RF transceiver


164


operates in approximately the 900 MHz band using “ook” (on/off keying) modulation, although it would be recognized by those of skill in the art that other methods of communication could be used. The processor


163


, via the transceiver


164


, sends an RF signal that contains the command entered by the user.




The TIU


12


is shown in more detail in FIG.


3


. The TIU


12


has a transceiver


120


that communicates with the transceiver


164


and antenna


165


located in the remote control


16


. Thus, in one embodiment the transceiver


120


is a 900 MHz band 9600 baud ook transceiver, although it should be understood that other transceiver configurations could be used. Further, an IR receiver could be used if the remote control


16


is transmitting IR signals, or any other wireless transceiver may also be acceptable depending on the wireless communication scheme implemented by the manufacturer.




The transceiver


120


receives the RF signal containing the command issued from the remote control


16


. The transceiver


120


passes the RF signal to a processor


121


that controls the TIU


12


. One suitable processor is part number M30624FGLFP manufactured by Mitsubishi, although other processors are also acceptable. The processor


121


decodes the command from the RF signal and issues an “acknowledgment packet” to the transceiver


120


for communication back to the remote control


16


. The acknowledgment packet is used to inform the remote control


16


that the command was successfully received by the TIU


12


.




The processor


121


in the TIU


12


extracts the command from the RF signal and passes it to the communication circuit


123


for conversion into spread spectrum format (as described below). The communication circuit


123


then passes the spread spectrum signal to a transmitter


127


for outputting the spread spectrum signal to the track layout


10


via conventional wiring. The spread spectrum signal is mixed with the AC voltage provided to the tracks from the TIU


12


via the power source


14


. It is contemplated that the processor may be capable of generating the spread spectrum signalling itself (such as a “system on a chip”), and in such an embodiment the communication circuit


123


would not be necessary.




In an alternate embodiment, it is possible for the user to communicate commands to the TIU


12


through use of a computer


30


. In this embodiment, the TIU


12


is connected to the computer


30


through a standard RS232 port


122


(or other suitable data port) and cable


124


. The commands normally entered on the remote control


16


are entered through a computer program executed by the computer


30


. The ability to write such a program is well within the expertise of a person of ordinary skill in the art of computer programming, and therefore no description of such a program is required herein. In the computer embodiment, the operation of the TIU


12


and other elements of the invention remains the same.




The model train(s)


11


will be described next with reference to FIG.


4


. The model train


11


has a printed circuit board


20


installed inside, which is shown in

FIG. 4

in block diagram form. The printed circuit board


20


has a processor


200


at the center of the model train's operations. The processor


200


is connected to a receiver circuit


201


that picks the spread spectrum signals off from the train track rails in the preferred embodiment. The receiver circuit


201


passes the spread spectrum signals to a communication circuit


202


. The communication circuit


202


, in one embodiment, correlates the spread spectrum signals into a fixed data pattern that is capable of being recognized by the processor


200


. When correlation is achieved, the data pattern is outputted by the communication circuit


202


to the processor


200


. In an alternate embodiment, it is contemplated that the processor


200


is capable of converting the spread spectrum signals itself, and/or is able to detect the command data from the spread spectrum signals (for example, a system on a chip). In these embodiments, the communication circuit


202


is not necessary.




The processor


200


, upon receiving the data pattern containing the command, outputs an acknowledge signal to the communication circuit


202


. The communication circuit


202


converts the acknowledge signal to spread spectrum format and outputs the acknowledge spread spectrum signal to a transmitter circuit


203


. Alternatively, the processor


200


outputs an acknowledge signal in spread spectrum format itself directly to the transmitter circuit


203


. In this alternate embodiment, the communication circuit


202


is once again not necessary. In either embodiment, the transmitter circuit


203


places the acknowledge spread spectrum signal on the train track rails, where it is picked up by the TIU


12


. The TIU processor


121


then converts the acknowledge spread spectrum signal into an RF signal, which the TIU transceiver


120


outputs to the remote control


16


.




In this way, there is “handshake” capability between the TIU


12


, model train printed circuit board


20


, and remote control


16


. The reason for such bidirectional capability is that it allows the data about the model train


11


to be received by the user. Such data may include, but is not limited to, the type of train


11


(diesel or steam), the digital address of the model train


11


, consist information, the actual speed of the train


11


, the types and amount of lights, whether there is a smoke unit present, the types of couplers, the various sound capabilities, the amount of memory available for sounds, the amount of voltage, current, and power the train


11


is using, and other such information. Thus, the TIU


12


and remote control


16


maintain all necessary, relevant information concerning the model train(s)


11


and their operation during use. This information is available to the user in order to enhance the user's enjoyment and realistic operation of the model train(s)


11


.




SPREAD SPECTRUM SIGNALLING




A description of the preferred embodiment of the present invention, wherein commands are transmitted by the user to the model train through spread spectrum signalling, will now be described. It should be understood that the following description describes one method of employing spread spectrum signalling. Other methods of spread spectrum signalling may also be used, and are considered within the scope of the present invention. The following description should therefore be considered illustrative, not limiting.




The present invention, in its preferred embodiment, uses spread spectrum signalling because model trains generally operate in a “noisy” electrical environment. Spread spectrum signalling utilizes an increased bandwidth technique in order to protect the integrity of the original signal and prevent the original signal from being distorted or changed by electric noise in the operating environment.




The operation is as follows. The user enters a command on the remote control


16


to be carried out by the model train


11


. The command is transmitted by the remote control


16


through radio frequency signals (or, in alternate embodiments, any other type of wireless transmission) to the TIU


12


. The transceiver


120


in the TIU


12


receives the command and passes it to the processor


121


(FIG.


3


). The processor


121


converts the command into a data transfer packet which contains a data stream representing the command. Each command will be prefaced with a preamble (typically one byte long) that is a fixed series of digital “1”s and “0”s. The preamble is used to achieve code and bit synchronization prior to receiving data. The data stream is therefore a series of digital bits (“1” and “0”). A typical command may comprise 4 to 8 bytes of data. During streaming sound operation (described in detail below), the typical sound packet may be much larger, on the order of 32 bytes. It should be understood, however, that the present invention comprehends and encompasses within the claims hereto commands of any size and length.




The data transfer packet is then passed by the processor


121


to the communication circuit


123


. The communication circuit


123


is used in the preferred embodiment to transmit and receive spread spectrum signals.




The communication circuit


123


receives the data transfer packet and converts each databit in the data transfer packet into 31 “chips.” Thus, the chipping rate is 31 times the data rate. The chips make up a pseudo-noise (P-N) code. The P-N code is a series of 31 “1”s and “0”s. The P-N code is fixed and does not change. Thus, each databit “1” in the data transfer packet is converted into the same 31-bit P-N code. The databit “0”s are converted into the. P-N code in inverted fashion; that is, if the first four chips of the P-N code are 0-1-1-0, for example, the first four chips of the P-N code inverted are 1-0-0-1.




A simple four-byte command, 32 data bits, in the data transfer packet is therefore converted into 992 chips, which means that it takes 992 chip times for a 4-byte command to be output by the communication circuit


123


. In the preferred embodiment, the chipping rate is 3.75 MHz. The actual data rate is thus 3.75 MHz divided by 31, or 121 KHz.




The communication circuit


123


passes the P-N codes to a transceiver


127


(the transceiver may be a part of the communication circuit or a separate element) that continually outputs the P-N codes representing the databits in the data transfer packet. This process continues until the data transfer packet has been sent. At that point, the transceiver


127


is turned off, and no further P-N codes are transmitted. The P-N codes are coupled to the track


10


in streaming fashion.




The foregoing. description represents the “transmitting” side of the spread spectrum signalling embodiment. What follows is a description of the “receiving” side. The receiver circuit


201


on the printed circuit board


20


(

FIG. 4

) located inside the model train


11


picks up the P-N codes from the track. The receiver circuit


201


passes the P-N codes to the communication circuit


202


.




Inside the communication circuit


202


is a 31 bit shift register


2022


(see

FIG. 15



a


). As the P-N codes come into the communication circuit


202


at the chipping rate of 3.75 MHz, they are shifted through the 31 bit shift register


2022


.




Parallel to the 31 bit shift register


2022


, there is a 31 bit memory


2024


that is permanently loaded with the original 31 bit P-N code in normal, noninverted fashion. (The 31 bit memory


2024


can be any structure capable of permanently retaining the P-N code, such as another, fixed 31 bit shift register or a suitable hard-wired configuration). Between the 31 bit shift register


2022


and the 31 bit memory


2024


are a series of exclusive-or (XOR) gates (collectively labelled


2026


). The inputs to the first XOR gate are the first stage of the 31 bit shift register


2022


and the first stage of the 31 bit memory


2024


. The inputs to the second XOR gate are the second stage of the 31 bit shift register


2022


and the second stage of the 31 bit memory


2024


, and so on. The XOR gates output a “1” when the inputs are different, and output a “0” when the inputs are the same. There are 31 XOR gates


2026


, corresponding to the 31 bits in each of the 31 bit shift register


2022


and the 31 bit memory


2024


.




An adder


2028


is connected to the 31 XOR gates


2026


. The adder


2028


counts the outputs of the XOR gates


2026


in order to determine how many of the outputs from the XOR gates were “0”. The output from the adder


2028


is therefore a number from 0 to 31; for example, if the output from the adder is 14, the communication circuit


202


knows that the output at 14 of the XOR gates was “0”.




As the data: is clocked through the 31 bit shift register


2022


, the outputs from the XOR gates


2026


will change with each clock pulse. Accordingly, the output from the adder


2028


will also change. When the P-N codes in the 31 bit shift register


2022


match the P-N codes in the 31 bit memory


2024


, the outputs of the XOR gates


2026


will all be “0” and the output of the adder


2028


will therefore be 31. At this point, the communication circuit


202


determines that the incoming data is correlated, i.e., the communication circuit


202


is now synchronized with the incoming data.




The communication circuit


202


now knows that every 31st clock pulse will be a databit in the original data transfer packet. The communication circuit


202


thereafter samples the output of the adder


2028


at every 31st clock pulse after correlation. This is done by summing the outputs of the XOR gates


2026


. If the total is 16 or greater, the communication circuit


202


determines that the original databit in the data transfer packet was a “0”. If the total of the outputs from the XOR gates is 15 or less, the communication circuit determines that the original databit was a “1”. The reasoning for this is as follows: the P-N code loaded into the 31 bit memory


2024


corresponds to a databit “1”. The more matches there are between the P-N codes passing through the 31 bit shift register


2022


and the 31 bit memory


2024


, the more likely it is that the original databit was a “1”. Because a match at the inputs of the XOR gates results in the XOR gate outputting a zero, if the P-N codes in the 31 bit shift register


2022


exactly match the P-N code in the 31 bit memory


2024


, the outputs of all 31 XOR gates will be zero and the sum of the outputs of the XOR gates will also be zero. The communication circuit


202


would therefore know that the original databit representing a portion of the command was a “1”. Thus, a majority of matches from the XOR gates results in a total sum of the outputs being 15 or less. The communication circuit


202


interprets that result to be a databit “1”. A minority of matches, in contrast, results in the total sum of the outputs of the XOR gates being 16 or higher, which the communication circuit


202


will determine to be a databit “0”.




In this fashion, the communication circuit


202


constructs the original information in the data transfer packet in binary form. When the communication circuit


202


reads a series of “1”s and “0”s that corresponds to the preamble, the communication circuit


202


then knows that the remaining “1”s and “0”s represent the command entered by the user. The communication circuit


202


provides the command to the processor


200


. The processor


200


thereafter takes whatever action is necessary that corresponds to the command (as discussed in more detail below).




The foregoing description of the spread spectrum signalling embodiment represents the ideal case. In actual practice, there is noise on the rails and in the operating environment that can distort or change the values of the P-N codes. Recognizing that digital “1”s and “0”s are actually simply some voltage value, it is common for electrical noise to change the voltage value of a binary signal to the point that it is indeterminant or false, that is, opposite of what it should be. Moreover, in the real world environment there are not instantaneous changes from 1 to 0. Instead, there is a transition region from 1 to 0 and from 0 to 1 wherein the value is indeterminant. Sampling a signal during the transition region can result in faulty data. The end result with respect to all these problems is that the communication circuit


202


may believe it is synchronized when in fact it is not, or it may not detect synchronization. Obviously, this is undesirable, as it can result in the entered command not being performed.




To overcome this problem, the preferred embodiment of the present invention takes several precautions. First, the threshold for determining correlation between the P-N codes in the 31 bit shift register


2022


and the 31 bit memory


2024


is set to less than 31; a non-limiting example may be 28. Thus, if the outputs of the XOR gates


2026


are such that at least 28 of the P-N codes in the 31 bit shift register


2022


match the P-N code in the 31 bit memory


2024


, the communication circuit


202


will consider itself synchronized to the incoming data stream.




Another problem that must be overcome concerns the clock rate. The phase of the clock signal is not known by the communication circuit


202


. In other words, data (P-N codes) could be shifting into the 31 bit shift register


2022


right when the P-N codes are in a transition region as described above. In the transition region, the data is in effect undefined. Therefore, there is the possibility that undefined data is being sampled out of the 31 bit shift register


2022


.




In order to solve this problem, the 31 bit shift register in the ideal case is replaced with a 62 bit shift register


2022


′ (see

FIG. 15



b


) that operates at twice the chipping rate; i.e., data is shifted into the 62 bit register


2022


′ at a rate of 7.5 MHz. This in effect means that for any given stage in the 62 bit shift register


2022


′, the next stage is 180 degrees out of phase. By this arrangement, if data is being clocked into one stage of the 62 bit shift register


2022


′ during transition, the same data will be clocked into the next stage when it is stable. The 62 bit shift register


2022


′ therefore functions like two 31 bit shift registers: stages 1, 3, 5, . . . 61 of the 62 bit shift register


2022


′ act like one 31 bit shift register, and stages 2, 4, 6, . . . 62 act like another 31 bit shift register that is 180 degrees out of phase with the first.




The 62 bit shift register


2022


′ is wired to the 31 XOR gates


2026


as explained above, except that only odd shift register outputs are used and the XOR gates


2026


provide an output at twice the rate of that described in the ideal condition. The outputs of the XOR gates


2026


are monitored by the adder


2028


to determine when the predetermined number (in the above example, 28) of matches occurs in order to determine synchronization.




In operation then, the communication circuit


202


will therefore determine when syncronization occurs by looking for 28 out of 31 matches. It should be apparent that when synchronization occurs, the communication circuit


202


thereafter monitors the outputs of the XOR gates


2026


after 62 clock cycles of the 7.5 MHz clock. The procedure then is the same as described in the ideal case for clocking in the remainder of the data and determining the original command entered by the user.




The communication circuits


123


and


202


in the TIU


12


and the engine board


20


of the model train


11


respectively are capable of both receiving and transmitting spread spectrum signals in the above fashion. Therefore, once the processor


200


in the model train


11


determines what the command is, the processor


200


assembles an acknowledge packet, which is intended to provide the TIU


12


and the remote control


16


with an indication that the command has been received. The acknowledge packet is sent to the communication circuit


202


for conversion into spread spectrum format as just described. This is then sent through the rails back to the TIU


12


where it is received and detected by the transceiver


127


and communication circuit


123


in the TIU


12


. The acknowledge spread spectrum signal is decoded as explained above and the acknowledge signal is passed to the TIU processor


121


. In this manner, all components of the model train system are aware of the operating conditions of the model train at all times.




SOUND SYSTEM FEATURES




Returning to FIG.


4


and the description of the printed circuit board


20


in the model train


11


, the processor


200


controls and drives the various component circuits located on the printed circuit board


20


. For example, the processor


200


drives the operation of the lights located on the model train


11


through the light driver circuit


204


. The smoke system is operated by the smoke system driver circuit


205


under command of the processor


200


. The couplers are controlled by the processor


200


via the coupler drive circuit


206


. The train's motor is controlled by the processor


200


through the motor control


207


. The sound system is controlled by the processor


200


through an audio amplifier/low pass filter circuit


208


′, which is connected to a speaker


208


″ (collectively, the “sound system circuit”


208


).




Certain sounds for the model train may be stored in a flash memory


209


, which in the

FIG. 4

embodiment is connected to the processor


200


. The processor


200


is capable of retrieving one or more sound files from the flash memory


209


, processing them, and outputting them to the sound system circuit


208


. In an alternate embodiment, such as a system on a chip configuration, the sound files are stored on the same integrated circuit as the processor. The sound files may be output from the processor


200


through a pulse width modulation (PWM) circuit


200


′ found in the processor


200


, or by a digital to analog converter circuit (DAC)


200


′. The processor


200


is capable of manipulating the sound file data in order to generate various sound effects, such as Doppler, as will be explained below.




The processor


200


is also capable of independently controlling the volume of different processed sounds, in response to commands entered from the user on the remote control


16


. The user can also control a “master” volume control by having the processor


200


adjust the DC voltage level of the audio amplifier


208


′ found in the sound system circuit


208


. Alternatively, the master volume may be controlled by the processor


200


limiting the pulse output level of the PWM circuit


200


′. This allows the user to adjust the volume of different sounds independently, and adjust the volume of the sounds as a whole. The user can also cut all sounds by turning the master volume to its minimum level. It is also desirable for the printed circuit board


20


to have a battery backup or capacitors (not shown) in order to allow the sounds to continue for a fixed amount of time even after the power has been removed from the track.




Thus, according to the invention, a user may want the train


11


to continually play a “chuffing” sound when the train


11


is in motion. The processor


200


will repeatedly retrieve the “chuff′ sound file from the flash memory


209


, process it, and feed it to the sound system circuit


208


. At the same time, the user may want the train


11


to play station and status announcements (for example, “now arriving at Union Station;” “we are currently 60 miles from Baltimore,” etc.). The processor


200


will retrieve the appropriate sound files, as described above. The user may also want the train whistle to blow every 15 seconds. Once again, the processor


200


will retrieve the sound files. All these sounds will play, at the same time, through the speaker


208


″ in the sound system circuit


208


.




At some point, however, the user may wish to lower the volume of the “chuff” sound in order to better hear the station announcements. The processor


200


is capable of reducing the volume of the chuff sound and increasing the volume of the station announcement sounds, while maintaining the volume of the whistle sound. Finally, the user may desire to lower the volume of all the sounds simultaneously, which the processor


200


accomplishes through the master volume control.




As previously stated with respect to the above-described embodiment, sounds are stored in the flash memory


209


on the printed circuit board


20


in the model train(s)


11


. It is also possible that sounds are stored in a flash memory


125


located in the TIU


12


(see FIG.


3


). In this way, once a user requests a sound on the remote control


16


, the TIU processor


121


retrieves the appropriate sound file from the TIU flash memory


125


, relays it to the communication circuit


123


for conversion to a spread spectrum signal, and sends it down the train track rails. The addressed model train


11


picks up the signal through the receiver circuit


201


, and passes it to the communication circuit


202


in order to retrieve the sound file embedded in the spread spectrum signal. The processor


200


processes the sound file outputs it to the sound system circuit


208


.




EXTERNAL AUDIO FEATURE




Although history has shown that the storage capacity of memory chips increases steadily as fabrication technology improves, there will always be a finite amount of memory available when an application requires resident file storage. For example, in the present embodiment, there will always be a limit on the amount of sound files that can be stored “on board” the model train


11


or in the TIU


12


. The present invention addresses this issue by allowing a user to connect the model train system to an external audio source. This is shown in

FIG. 3

, described next.




As shown in

FIG. 3

, the TIU


12


is connected to an external audio source


40


through standard left and right stereo jacks


126


or other suitable connections. The external source


40


may be a CD player, DVD player, cassette player, mini-disc player, memory stick, mp3 player, or other sound source. Because the TIU


12


is also capable of communicating with a computer


30


, as explained above, the external source here may also be a computer's hard drive or an open modem connection to the Internet via the computer.




When the user desires to play the external audio source


40


, he or she enters an appropriate command on the remote control


16


, which informs the TIU


12


that it will be receiving sounds from the external audio source


40


. The TIU processor


121


then sends a command to the model train


11


to stop playing any sounds previously commanded by the user. The model train


11


receives the “stop” command and stops playing all stored sounds.




Once the external audio source


40


is activated, the sounds “stream” from the external audio source


40


to the TIU


12


to the model train


11


, where the sounds are heard emanating from the speaker


208


″ on board the train


11


. In this way, the user will interpret “real-time” sounds coming from the model train


11


.




This is accomplished through the use of the aforementioned spread spectrum signals. The spread spectrum signal is capable of carrying large amounts of data, such as continuously played sounds from the external audio source


40


. Moreover, the rate at which data is passed from the TIU


12


to the tracks in the form of spread spectrum signals is very high (the aforementioned example being approximately 121 KHz). This high data rate also allows for real-time sound to be sent down the tracks.




The sounds enter the TIU


12


from the external audio source


40


as line level audio via the aforementioned left and right stereo jacks


126


or other connections. The TIU processor


121


samples the sounds and converts them into digital data (by a standard A/D converter, not shown), which is passed to the communication circuit


123


. The communication circuit


123


then embeds the digital sound data into a spread spectrum signal which is sent out to the train track rails as previously described. The model train receiver circuit


201


picks up the spread spectrum signal, and passes it to the train communication circuit


202


, which decodes the digital sound data from the spread spectrum signal. The communication circuit


202


passes the digital sound data to the processor


200


. The train processor


200


then converts the digital sound data into analog form through a DAC and passes the analog signal to the sound system circuit


208


, which plays the analog sound through the speaker


208


″. This process repeats itself at a high enough rate that the user hears continuous sounds playing from the model train


11


.




In this embodiment, the sounds from the external audio source


40


are converted into ADPCM (Adaptive Differential Pulse Code Modulation) format at a rate of 4 bits/sample and 11,000 samples/second. This requires a data rate from the TIU


12


to the train track rails of at least 44,000 bits/second. The aforementioned illustrative data rate of 121 KHz meets this requirement.




The left and right stereo sounds received by the TIU


12


via the left and right stereo jacks


126


are added by the TIU processor


121


and output to the tracks in mono form. As described previously, the user can adjust the master volume of the model train


11


in order to increase or decrease the volume of the sound output by the model train


11


.




It should be apparent that the present invention provides the user with a number of exciting options. For example, the user may connect the TIU


12


to a CD player and have the model train “play” the user's favorite songs. The user may have a unique pattern of train sounds specifically created by the user and stored on the user's computer hard-drive. This invention enables the user to play his or her customized “train sound track” through a model train


11


.




The system disclosed herein provides other sound possibilities. For example, the external audio source


40


may be a microphone. Following the same steps as described above, the user may speak into the microphone and have his or her own voice transmitted down the train track rails by the TIU


12


(via spread spectrum signals), where it will be converted by the train communication circuit


202


and processor


200


and played through the sound system circuit


208


on the model train


11


. In place of an external microphone, the present invention also contemplates having a microphone


166


built into the remote control


16


, which the user could turn on with one of the push buttons


162


on the remote control


16


, and then speak directly into the remote control microphone


166


.




Through this feature of the present invention, the user can be the train “engineer” and announce train station stops, status updates, etc. Of course, this feature also enables the user to playfully interact with other people in the room. For example, the user may have the train


11


say “happy birthday” to someone else in the room, or have the train


11


call to the family dog. The possibilities are endless, and the foregoing are merely examples.




CUSTOM SOUND




Another aspect of the present invention allows users to store their own custom sound files in the flash memory


209


located in the model train


11


on the printed circuit board


20


. In an alternative embodiment, the custom sound files are stored in the flash memory


125


located in the TIU


12


. The general concepts are the same for both embodiments.




The user is capable of entering a “record” command on the remote control


16


. The record command is sent via the RF signals to the TIU


12


, which embeds the command into a spread spectrum signal and passes the command down the rails to the model train


11


. The command is received and processed by the receiver circuit


201


, communication circuit


202


, and train processor


200


, respectively. The processor


200


then checks the flash memory


209


on the printed circuit board


20


for available capacity. Assuming there is capacity, the processor


200


creates a sound file in the flash memory


209


and assigns a′ ID to the file. The flash memory


209


then is placed in “record” (or “store”) mode and awaits sound data.




The sound data can come from any of the above-described sources identified with respect to the external audio source


40


, i.e., CD players, tape players, mini-disc players, mp3 players, memory sticks, computer hard-drives, Internet websites, or someone's voice via the microphone. After the user enters the “record” command on the remote control


16


, the user then enters the command informing the TIU


12


that sounds will be coming from the external audio source


40


. The sounds from the external audio source


40


are embedded as digital data into a spread spectrum signal by the communication circuit


123


. The signal is passed down the train track rails where it is received by the model train


11


. The train's communication circuit


202


and processor


200


decode the sound digital data from the spread spectrum signal and pass it to the flash memory


209


, where it is stored as digital sound data in the newly created sound file. When the user enters the “stop recording” command on the remote control


16


, the, processor


200


stops the flow of data into the sound file. In one embodiment, the sound file is recorded on the fly into the flash memory


209


in the engine board


20


. In another embodiment, the sound file may first be stored in the flash memory


125


in the TIU


12


, and then transferred at a later time into the flash memory


209


in the engine board


20


.




The flash memory


209


now has a unique sound file recorded by the user. The train processor


200


passes the ID of the unique sound file to the TIU


12


in an information packet through the track rails, and the TIU


12


passes the information on to the remote control


16


via RF signals. The remote control


16


can then provide the user with the ID of the newly created sound file so that the user can recall that ID on the remote control


16


when he or she wants the train


11


to play the unique sound file. Alternatively, the user can assign an ID to the recorded sound file on the remote control


16


(for example, pressing a combination of three push buttons


162


on the remote control


16


will activate the recorded sound file). The user-assigned ID is then passed along to the train processor


200


, which stores the user-assigned ID in memory and activates the recorded sound file when the user-assigned ID is entered on the remote control


16


.




In the alternative embodiment, where the recorded sound file is stored in the flash memory


125


in the TIU


12


, the system works substantially the same way. In this embodiment, however, the TIU processor


121


converts the sounds to be recorded into digital data and stores them in a sound file created in the TIU flash memory


125


. When the user wishes to have the recorded sound file played, the TIU processor


121


retrieves it from the flash memory


125


and passes it to the communication circuit


123


, which embeds the digital sound data from the sound file into a spread spectrum signal. This is then output to the train track rails, where it is picked up and played by the model train


11


, as has been previously described.




This “recording” feature also expands on the capabilities of the model train system for the user. For example, a user may sing “happy birthday” to his or her daughter and store the song in a sound file in the flash memory (


125


or


209


). When the daughter enters the room, the user can activate the sound file and the daughter will hear the train “sing” happy birthday to her.




Another example concerns new train sounds. Model train makers are constantly searching for new and different sounds that simulate real-life train sounds. A manufacturer may make an upgrade available with new sound files. With the present invention, the user could purchase a CD (for example) having the new sound files, and record the new sound files from the CD to the flash memory (


125


or


209


).




Further, because of the present invention's capability of interacting with a computer


30


, the manufacturer may make the new sound files available for download from the manufacturer's Internet website. The user can connect the model train system to his or her computer, access the website, and download the new sound files directly into the flash memory (TIU


12


or model train) using the “record” feature.




Returning to the ability of the present invention to play streaming sounds from an external audio source


40


, the embodiment described above uses the spread spectrum signaling method to digitize the sound and provide it to the train processor


200


. The train processor


200


then converts the digitized sound to analog for playing through the sound system circuit


208


. In an alternate embodiment, the present invention does not digitize the streaming sound. This may be referred to as the “analog” embodiment, as shown in

FIG. 4



a.






The setup for the analog system is similar to that shown in FIG.


3


. The TIU


12


is connected to an external audio source


40


, as described above. In this embodiment, rather than converting the audio signal into digital data for embedding into a spread spectrum signal, the TIU


12


uses FM modulation techniques. In one non-limiting example, the audio signal is FM modulated at a frequency of 10.7 MHz. The peak frequency deviation is about 40 KHz. This was chosen because it is similar to modulation used for FM radio when only a mono receiver is used. It should be understood, however, that other frequencies and deviations may be used, and are considered within the scope of the present invention.




In this embodiment, it is contemplated that an FM signal transmitter


127


is housed in the TIU


12


. In the preferred embodiment, the TIU


12


has two inputs


126


for audio in, although one input is also possible, as is more than two. In the preferred embodiment of two inputs, one is line level and the other is microphone level. When an audio signal is presented at either one of these inputs, the FM signal transmitter


127


is enabled. In this embodiment, there is a delay between the end of the audio signal and the disabling of the FM signal transmitter


127


. This is done so that the silence between songs on a CD or other source will not cause the model train


11


to return to playing normal train sounds, such as chuffing.




The FM signal transmitter


127


may be any suitable one available in the art. An acceptable FM signal transmitter


127


consists of a 10.7 MHz LC transistor oscillator, an output driver, and a coupling power source. A varactor in the FM signal transmitter


127


varies the transmitter's output frequency with changes in the audio input. The driver boosts the transmitted FM signal and the coupling power source couples the 10.7 MHz signal onto the train track rails.




In the analog embodiment, an FM receiver integrated circuit (IC)


210


is located on the model train's printed circuit board


20


. Once the FM receiver


210


receives a 10.7 MHz signal, it signals the train processor


200


to stop producing other sounds and the sound system circuit


208


is driven by the output of the FM receiver IC


210


. This is described in more detail below.




The receiver circuit


201


picks up the FM signal from the train track rails (in a three-rail system, this signal is found on the center rail). This signal is filtered in a 10.7 MHz ceramic filter


211


. The filtered signal is then passed to the FM receiver IC


210


. Any standard FM receiver IC


210


or circuit may be used for this purpose. Non-limiting examples of such ICs are the Philips SA614 and the Motorola MC3371.




The FM receiver IC


210


receives the filtered signal and amplifies it. The amplified signal is then externally filtered in another ceramic filter


212


. The second filtered signal is then passed through a limiter


213


and into a discriminator


214


. The output of the discriminator is the audio signal. This audio signal is muted if the received 10.7 MHz signal is not strong enough. If it is sufficiently strong, the audio signal is passed to the sound system circuit


208


where it is amplified and played through the speaker


208


″.




Alternatively, the FM receiver IC


210


mixes the received filtered signal down to 450 KHz. The source for the 10.24 MHz local oscillator is a crystal. The 450 KHz signal is then amplified and externally filtered in an LC filter


215


. The second filtered signal then goes through a limiter


216


and into the discriminator


217


where the audio signal is recovered. Once again, this audio signal is muted if the 450 KHz signal is not strong enough. If the signal is strong enough, the audio signal then goes to the audio amplifier where it drives the speaker


208


″ in the sound system circuit


208


.




DIAGNOSTIC INFORMATION




The ability of the present invention to communicate with a computer


30


takes advantage of the two-way “handshake” capability between the TIU


12


and the model train


11


. As previously stated, the train processor


200


is capable of outputting a large amount of information concerning the status of the model train


11


. This information can be “uploaded” from the model train


11


via the TIU


12


to the Internet. Thus, a user having a problem with a particular model train


11


can put the train


11


on the track


10


and connect the TIU


12


to a computer


30


. Once the computer


30


is linked to the Internet via a modem connection, the TIU


12


can retrieve operating information about the model train


11


from the train processor


200


and upload that information to a troubleshooting website, manufacturing website, dealer website, or other location. A technician at the other end can then retrieve and analyze the train information and propose solutions to any operating difficulties the user is having. It is also possible that the technician can download a software patch or other solution to the train


11


through the open modem connection, in the manner described above concerning the playing of sounds from an external audio source


40


. Alternatively, a user may be able to download a software patch from a website directly.




SPEED CONTROL OVERVIEW




Another aspect of the invention, “speed control,” will be described next. First, some background information concerning the state of the prior art is appropriate.




For example,

FIG. 5

illustrates a traditional speed control for a model train corresponding to the aforementioned “legacy mode.” A transformer


1


powers the track


2


with AC/DC voltage. The AC/DC voltage is then fed directly into the engine


3


of the train. The engine


3


includes a motor drive circuit


4


and a motor


5


. The motor drive circuit


4


receives the AC/DC voltage and applies this to the motor


5


directly, or indirectly such as through rectification in the case of an AC track voltage and a DC motor.




In the aforementioned setup, speed control for the train is accomplished by manual control of the output voltage supplied by the transformer


1


. A user may manually adjust the output voltage of the transformer


1


, e.g., using a control knob or throttle arm, to a predetermined value which would correlate with a desired speed for the model train. Accordingly, the higher the voltage output of the transformer


1


, the faster the train will go.




The problems associated with the “legacy mode” of operation will now be discussed with respect to FIG.


6


. The graph shown in

FIG. 6

compares the output voltage of the transformer


1


versus the resulting speed of the train. The transformer


1


can be adjusted from some non-zero starting voltage


6


. The gap between zero volts and the non-zero starting voltage


6


is used as a signaling mechanism, whereby a train may interpret momentary interruptions in track voltage as a command to shift to a neutral state or to change direction.




As is clear from the graph, the speed control of the trains in the “legacy mode” of operation in the prior art is dependent upon the load of the train. The two lines represent the correlation between voltage output and speed for differing loads, one for light-load and one for heavy load. When an engine is lightly loaded (e.g., few or no cars, going downhill), less voltage is required to achieve a given speed. Accordingly, with increasing load (e.g., more cars, going uphill) more voltage is required to maintain the given speed.




As evident from

FIG. 6

, train load is an important parameter for speed control. As such, a given desired speed indicated by a “*” on

FIG. 6

will require two different voltages marked on the graph as “X”, one voltage for low load and another voltage for high load. Accordingly, if a user desires to accurately control speeds at desired values, he/she must manually attempt to calculate and/or conduct repeated tests in order to establish a look-up table/graph that will list the required voltage for every known load. In effect, a user would have to manually produce data, similar to what is shown in

FIG. 6

, for every different load they will operate with. It is quickly apparent that such an undertaking would be practically impossible.




Moreover, the resulting data (i.e., look-up table or chart) would still not take into consideration the inherent load changes that take effect while driving the train throughout the layout. In other words, the load lines shown in

FIG. 6

are based on the assumption that load will remain fixed in value (e.g., solely dependent on number of trains, etc.). However, in practice, load will continuously change while driving the trains throughout the layout in response to certain factors related to the layout; for example, going up or down a hill or around a curve. Therefore, even if a user could produce a look-up table or chart, the user would still not be able to automatically maintain a constant speed throughout the entire layout. Additionally, it should be noted that it is typical for there to be large variations between train engines (particularly from different manufacturers). Thus, manual control of the speed of one engine will not apply to other engines.




An additional limitation of the “legacy mode” of operation occurs at relatively slower speeds. At a given load, only a portion of the power source's voltage range can be used to operate an engine over the desired speed range. As shown in

FIG. 6

, the load lines do not extend to a point where either the voltage or the train speed is zero. This is because the train must initially be supplied with sufficient voltage to overcome static friction between the train and the track. Once the train begins to move, the slope of the line representing the correlation of speed vs. voltage is larger as a result of the smaller amount of dynamic friction; hence, it is difficult to control the train at low speeds.




Specifically, small manual adjustments using a power source's control knob or throttle arm cause dramatic changes in speed, thereby making it is difficult to achieve or maintain consistent slow speed operation. Moreover, a slow-moving engine stalls at curves or when climbing a hill because the supplied voltage cannot provide enough motor current to overcome the additional torque. Once stalled, the voltage must be increased to supply enough current to again overcome or break through the static friction. Additionally, in the case of lightly loaded engines, the power source voltage itself may drop out as the speed of the engine is lowered.




In summary, the “legacy mode” speed control in the prior art does not automatically provide a constant speed around the track regardless of static and dynamic load changes. Moreover, the prior art provides poor speed control at slow speeds, resulting in a jerk, snap-type motion when moving the trains from rest or relatively slow speeds.




Turning to

FIG. 7

, the novel speed control system of the present invention will be described in more detail. Importantly, this method can be used with existing power sources. Generally, the speed control system of the present invention comprises a feedback loop that maintains a constant desired speed of the train regardless of motor imperfections and/or load variations such as adding cars, climbing a hill or traversing a curve.




The motor control


207


includes a motor drive circuit


2071


, a motor


2072


and a speed sensor


2073


. The motor drive circuit


2071


includes a bidirectional pulse width modulation circuit (“PWMC”)


2071


′ illustrated in FIG.


8


. The PWMC


2071


′ includes a two-transistor with relay “H” bridge which provides bi-directional drive to the DC motor. The bridge is pulse-width-modulated at a fixed and inaudible frequency of approximately 20 kHz. The single-ended bus voltage to the bridge is rectified from an AC track voltage. The “H” bridge configuration permits forward or backward drive to the motor. The “H” bridge is commonly used and maintaining this topology allows the processor


200


to emulate existing variable track voltage speed control systems by completely enabling the forward or reverse bridge paths without modulation. In this manner, the motor drive will be directly proportional to the rectified track voltage and will emulate the behavior of legacy systems, thereby making the SCS control easily adaptable with existing systems.




The PWMC


2071


′ functions to alter the duty cycle at which the track voltage is pulsed into the motor


2072


. Accordingly, at any given track voltage, the PWMC


2071


′ can control the train speed by changing the duty cycle at which the voltage is applied to the motor.




The processor


200


senses the motor speed via the speed sensor


2073


and modulates the turn-on interval or duty-cycle of the “H” bridge transistors to modulate the current applied to the motor


2072


. With a striped speed sensor


2073


, the processor


200


accumulates the transitions in a fixed control interval. The processor


200


compares the number of transitions with the commanded speed scaled to transitions per control interval.




For example, if the fixed interval is 57 milliseconds, then a 10 mph scale speed would generate 40 transitions per interval using a 24-stripe sensor. The error is used to proportionally increase or decrease the duty-cycle to the motor


2072


. Additionally, the acceleration is estimated by comparing the transition count from the present time interval to the previous time interval. This acceleration is also used to increase or decrease the duty-cycle. This implements a so-called PID (proportional-integral-derivative) control loop and can be stated algorithmically as:








D




n




=D




n−1




+k




prop


*(


S




n




−S




target


)+


k




deriv


*(


S




n




−S




n−1


)






where:




D


n


, D


n−1


are the duty-cycle to the motor drive circuit for the present and previous control interval




S


n


, S


n−1


are the sensed motor speed for the present and previous control interval




S


target


is the commanded target speed




k


deriv


, k


prop


are weighting multiplier or “gains”




The weighting multipliers are not necessarily constant and may be adjusted as a function of target speed and sign of the difference value to which they are applied. At slow motor speeds in particular, the characteristics of torque variations in brushed DC motors demand careful selection of these multipliers.




Accordingly, the PWMC


2071


′ serves the important function of controlling train speed independently of the voltage across the track. For example, if the track voltage is set at 20 VAC which equates to a set scale miles per hour (“smph”) (up to a maximum of 100 smph), then the PWMC


2071


′ is capable of increasing the speed of the train by increasing the duty cycle (i.e., increasing the time that the voltage is applied to the motor


2072


) for the application of the 20 VAC to the motor


2072


. Similarly, the PWMC


2071


′ can reduce the speed of the train (to as little as 1 smph) by decreasing the duty cycle. The PWMC


2071


′ thus enables the processor


200


to adjust the speed of the train over a wide range with the same track voltage.




When desired to run in “legacy mode”, the user enters the request on the remote control


16


, which will send a signal to the processor


200


in the printed circuit board


20


of the train(s)


11


. Accordingly, the processor


200


sets the PWMC


2071


′ to a fixed maximum value that remains constant regardless of the actual speed of the train


11


sensed by the speed sensor


2073


.




SPEED CONTROL—CONVENTIONAL MODE




The general functional and operational interrelationship between the elements of the novel speed control of the present invention will now be discussed with respect to “Conventional Mode”. It should be noted that the following description is for exemplary purposes only and that alternative operational sequences are possible.




Returning to

FIG. 7

, the power source


14


supplies a voltage across the track. The amount of voltage applied to the track is directly related to the desired speed for the train(s) on the track, as will be discussed in more detail below. The track voltage will be picked up by rollers (not shown), which also pick up the digital commands sent by the TIU


12


as discussed above, on the underside of the train(s)


11


. The track voltage is sampled by an A/D converter


310


which then converts the voltage into a digital signal and outputs the digital signal to the processor


200


. Accordingly, the digital signal represents a speed command of the user. That is, the track voltage set by the user is indicative of the user's desired speed for the train(s)


11


(more voltage=more speed). The processor


200


utilizes the sampled track voltage to access a look-up table stored in memory that indicates what the speed of the train should be at the sampled track voltage. The looked-up speed corresponding to the sampled track voltage becomes the user's desired speed. The processor


200


also receives a signal from the speed sensor


2073


which is indicative of the actual train speed. The processor


200


compares the desired speed (i.e., speed command) with the actual speed and adjusts the duty cycle accordingly. The look-up table applies to all trains equipped with the present invention so that the resultant speeds are the same.




An example of operation will now be discussed. To begin, a user manually adjusts the power source


14


to a given voltage corresponding to a desired speed. Under normal conditions (i.e., constant load, etc.), the train(s)


11


will gradually reach the desired speed. However, when the train(s)


11


traverses a curve or goes up/down a hill, or box cars are added, the load will change. Accordingly, the set voltage and default duty cycle will no longer be capable of maintaining the desired speed.




In the “legacy mode” of the prior art control systems discussed above with respect to

FIG. 5

, when a user set the track voltage by manually adjusting the transformer


1


for a desired speed, if the load on the train increased, the user had to again increase the track voltage by manually adjusting the transformer


1


in order to maintain the desired speed. As was seen in

FIG. 6

, this resulted in a speed control system that was dependent upon the load, leading to an inefficient and impractical speed control scheme where the user must continuously adjust the track voltage to maintain a desired speed.




In contrast, the present invention automatically provides a constant speed for the train


11


independently of any load changes (within limitations set by the available power supplied to the track). Consequently, once the user sets a desired speed (i.e., by manually setting a voltage), the system will maintain that speed.




Returning to

FIG. 7

, how the present invention automatically maintains a constant speed independently of load will now be explained. The speed sensor


2073


is coupled to the motor


2072


. The speed sensor


2073


is preferably a flywheel that is attached to the motor shaft (not shown) thereby rotating at the same rate as the motor


2072


, so as to measure the angular rotation of the motor


2072


. Either a reflective or transmissive optical sensing method can be employed depending on the available space in the engine housing. The reflective method uses an LED (not shown) to illuminate the flywheel which is marked with alternating reflecting and non-reflecting stripes. As the flywheel turns, a photodetector detects the rate of optical transitions thereby indicating speed. Alternatively, the transmissive method attaches a circular disk with radial stripes or spokes to either transmit or block the LED illumination. Further, the motor shaft can itself be marked similarly to the flywheel. The gear ratio for typical model engines is ¼″ of track motion per motor revolution. For {fraction (1/48)}th scale, 1 mph is equivalent to 1.47 motor revolutions/sec. For example, if the flywheel is marked with 24 stripes or spokes, there will be 48 transitions per revolution or 70.6 photodetector transitions per scale MPH.




Alternatively, the speed can be measured by sensing the per-revolution variation in motor current due to the self-commutation. Commutation causes an instaneous, measurable change in current (sensed as a feedback pulse) as windings move to the next brush in motors. This occurs a fixed number of times per motor revolution. Since the commutation sequence repeats with each revolution, there is a discrete number of feedback pulses per revolution, which, in essense, is an odometer. The processor


200


can sense the motor current through a sense resistor (not shown) and algorithmically estimate the speed. The back-emf of the motor


2072


can optionally be simultaneously sensed to improve the estimate. The advantage of this speed sensing method is that it can be retro-fitted without modifying the motor mechanical assembly; as such, it is compatible with existing motors.




Another method of sensing the motor speed is the use of a magnetic hall effect sensor or switch that comprises a magnetic ring with bands of alternate polarities. The speed at which the polarities change is measured, in a manner similar to the optical flywheel described above.




The desired track voltage is sampled by the A/D converter


310


and converted into a digital signal for outputting to the processor


200


. This digital signal represents the desired speed. Accordingly, the processor


200


is made aware of the desired speed for the train(s)


11


. The speed sensor


2073


will continuously monitor the motor speed as an indication of the train speed and output this reading into the processor


200


.




Accordingly, the processor


200


will adjust the duty cycle according to a comparison that is made between the desired speed represented by the track voltage and the actual speed sensed by the speed sensor


2073


.




For example, if a user enters on the remote control


16


a desired speed of 10 smph, the power source


14


will output the corresponding voltage over the track (similarly, the user may manually set the power source


14


at the desired voltage representing the desired speed). Accordingly, the train(s)


11


will gradually reach 10 smph at which point the measured speed and desired speed will have a substantially one-to-one correspondence and the processor


200


will maintain the current duty cycle. However, if, for example, the train(s)


11


goes up a hill, the same track voltage will not be sufficient to maintain the desired speed because of the increase in load. As a result, the train will begin to slow down as it climbs the hill.




The speed sensor


2073


will immediately sense the decrease in motor speed. Accordingly, when the processor


200


compares the desired speed (i.e., sampled track voltage) with the actual speed (from speed sensor


2073


), the processor


200


will know that the train(s)


11


is now going slower than the desired speed. In response, the processor will increase the duty cycle using the PWMC


2071


′ and thereby increase the power applied to the motor


2072


. This feedback loop will continue, with a continuously increasing duty cycle, until the measured speed is again in a substantially one-to-one correspondence with the desired speed. The same process occurs when the train(s)


11


goes down a hill, except that the processor


200


will decrease the duty cycle.




Turning to

FIG. 9

, a curve illustrating the relation between speed and track voltage of the present invention is illustrated in comparison to the conventional speed vs. track voltage curve shown in FIG.


6


. As is evident, the speed control system of the present invention results in a single curve that is independent of load, whereas the conventional speed control system includes a line for each load (light-load and heavy load shown). Accordingly, for every given track voltage, the present invention will maintain the corresponding speed by continuously adjusting the duty cycle. The single curve derived from the speed control of the present invention will always lie to the right of the light/heavy load lines of the conventional system so that the processor


200


can modulate the motor voltage at less than or equal to the maximum voltage available.




It can be seen from

FIG. 9

that the single curve of the present invention is defined by three distinct regions. Region


1


defines the track voltage over which the train does not move (i.e., speed=0). In other words, if a user manually turns on the power source


14


to a track voltage in Region


1


, the processor


200


will direct the PWMC


2071


′ to a zero duty cycle. Therefore, the motor


2072


will not receive any power. Region


1


is set to be above the drop out voltage of the particular power source in order to be compatible with the existing signaling method for interrupting track voltage in order to make a transition between forward, reverse, or neutral modes of operation for the train. Region


2


defines a gradual increase in speed with increased track voltage and Region


3


defines an increased slope for the speed vs. track voltage curve.




The reduced slope of Region


2


provides a significant advantage. Finite speed changes at slower speeds are more noticeable than at faster speeds. For example, the change in speed that a car makes from 60 mph to 65 mph is much less noticeable than a car that changes speeds from 5 mph to 10 mph. Accordingly, the reduced slope of Region


2


provides an improved resolution for slow speed operation. Moreover, all available power sources inherently have finite output impedance (i.e., meaning their voltage drops slightly with increasing load) causing load disturbance and/or change. The effects of such load disturbances and/or changes are relatively higher for slow speed operation versus high speed operation. Accordingly, the reduced slope of Region


2


helps mitigate these effects on the desired speed of the train.




In fact, because the PWMC


2071


′ is directed by the processor


200


to continuously modulate the voltage applied to the motor


2072


, the present invention provides the capability to set forth any range of speed vs. track voltage curves by programming the processor


200


to control the PWMC


2071


′ in the desired manner. For example, a user can provide dramatic increases in speed (resulting in an increased slope) by increasing the rate at which the duty cycle increases in response to an increased track voltage. Similarly, a user can provide very fine speed adjustments by decreasing the rate at which the duty cycle increases in response to an increased track voltage. Accordingly, the accuracy and precision of slow speed operation is significantly improved.




SPEED CONTROL—COMMAND MODE




A discussion of the novel speed control of the present invention is now discussed with respect to the “Command mode”, which can be selected via the remote control


16


. It should be understood that trains equipped with the engine board


20


in

FIG. 4

are capable of operating in either Command or Conventional mode. The default is Command mode. However, a user may disable Command mode by entering an appropriate command on the remote control


16


, at which point the train will operate in Conventional mode. Entering another command on the remote control


16


will return the train to Command, mode.




When in “Command mode”, the user will adjust the power source


14


such that the track voltage is set at a pre-determined maximum value (e.g., the power source's maximum). Once the pre-determined maximum value for the voltage across the track is set, the user no longer needs to adjust the track voltage for changing speeds.




Turning back to

FIG. 7

, the speed control system used in “Command Mode” is the same as used in the “Conventional Mode” and thereby operates in the same manner. That is, the processor


200


compares the speed command and the actual speed and adjusts the duty cycle to obtain the desired speed. However, in “Command Mode”, the speed command is no longer a function of the track voltage selected by the user either directly or indirectly. As discussed above, the track voltage is set at a pre-determined maximum. Instead, the speed command is directly inputted into the printed circuit board


20


of a particular train


11


from the remote control


16


. Each train


11


has a unique digital address. Accordingly, a user will first input into the remote control


16


a specific train


11


whose speed the user wants to change, and then inputs the desired speed.




The remote control


16


will output a signal embedded with the digital address and the desired speed into the TIU


12


and onto the track. The signal will “find” the train(s)


11


whose digital address matches the one embedded in the signal. The signal will then be inputted into the printed circuit board


20


of the selected train


11


and be fed into the processor


200


.




At this point, the speed control feedback works similarly to the “Conventional Mode”. That is, the processor


200


receives the speed command in digital form. The A/D converter


310


samples the track voltage, which is set at the desired maximum voltage, and outputs a signal to the processor


200


. The processor then compares the speed command to the maximum voltage and determines a duty cycle that will accurately modulate the maximum track voltage to the motor


2072


in order to achieve the desired speed. Accordingly, in “Command Mode”, a user can select different speeds for every train


11


on the track by simply using the remote control


16


.




Moreover, in “Command Mode”, the acceleration and deceleration at which the train(s)


11


reach the desired speed can be adjusted. In addition to a default acceleration/deceleration, there are a plurality of other acceleration/deceleration rates that are stored in flash memory


209


. More acceleration/deceleration rates can be added by inputting and storing the desired rates using the remote control


16


. The user simply accesses the appropriate file in the flash memory


209


related to the acceleration/deceleration rates and selects the desired rate. Even further, the acceleration rates can be distinct and independent from the deceleration rates, thereby allowing the user to have different rates for acceleration and deceleration.




COUPLER DESIGN




Another inventive feature of the present invention is a new coupler design. Couplers are used on model trains to connect a train to one or more box cars, oil tankers, other trains, or other loads. The couplers also connect between box cars, for example.




Turning to

FIG. 10



a


, a conventional mechanical coupler


100


for connecting and disconnecting trains is illustrated. The main components of the conventional mechanical coupler


100


include a knuckle


101


, a knuckle spring


102


, a knuckle pin


103


, a housing


104


, a housing lock pin


105


, a latch member


106


, a latch member hole


107


, a latch member spring


108


, a latch pin


109


, a latch plate post


110


, a latch plate


111


, a knuckle latch ramp


112


and a knuckle latch notch


113


.

FIG. 10



b


illustrates a bottom view of the latch member


106


taken from

FIG. 10



a


. The operation and functionality of each of the components of the conventional mechanical coupler will now be described.





FIGS. 11



a


through


11




c


illustrate the process by which two trains are coupled together.

FIG. 11



a


shows two conventional mechanical couplers


100


on different trains (not shown) in the unlocked open position, where one train is approaching the other. Each knuckle includes two arms


101


′ and


101


″. Knuckle arm


101


″ includes on an outer portion thereon the knuckle latch ramp


112


and the knuckle latch notch


113


. The knuckle


101


is rotatable about the knuckle pin


103


and is biased open by knuckle spring


102


(bias illustrated by semi-circular arrow in

FIG. 11



a


). Turning to

FIG. 11



b


, the user will direct one of the trains into the other such that the respective knuckle arms


101


′ pass each other and come into contact with an inner surface


104


′ of the housing


104


of the other coupler


100


. The contour of the inner surface


104


′ of the housing


104


causes the knuckle


101


to rotate about its knuckle pin


103


toward the latch pin


109


that is positioned within an opening of the knuckle's housing


104


(see

FIG. 10



a


). As seen in

FIGS. 11



a


through


11




c


, the rotation of the knuckles


101


will cause the knuckle latch ramp


112


(shown in

FIG. 10



a


) on the respective knuckles


101


to engage the latch pin


109


. This mechanical interaction between the knuckle latch ramp


112


and the latch pin


109


will raise the latch pin


109


and latch member


106


against the bias of latch member spring


108


. When the knuckle


101


has rotated a sufficient amount, the latch pin


109


will be forced into the knuckle latch notch


113


via latch member spring


108


so that the coupler


100


will belocked in the closed position (see

FIGS. 10



a


and


11




c


).




The conventional mechanical coupler


100


can be opened in two ways: either by manually raising latch pin


109


out of knuckle latch notch


113


, or by providing a magnetic pull on latch plate


111


to raise latch pin


109


out of knuckle latch notch


113


. The magnetic pull is derived from an electromagnet (not shown) that is built into the track layout at a given location. Accordingly, a user will need to position the train such that the latch plate


111


is positioned over the electromagnet. The user will then energize the electromagnet for pulling the latch plate


111


toward the electromagnet, thereby moving the latch pin


109


out of the knuckle latch notch


113


. Once the latch pin


109


is raised out of knuckle latch notch


113


, knuckle spring


102


will force the knuckle


101


(and knuckle latch ramp


112


/knuckle latch notch


113


) back into the unlocked open position (

FIG. 11



a


). When the manual or magnetic force is removed, latch member spring


108


will return the latch member


106


and latch pin


109


back into their normal position (shown in

FIG. 10



a


).




One of the disadvantages of the conventional mechanical coupler


100


is that, to unlatch a coupler


100


, the user must either manually raise the latch member


106


every time a de-coupling is desired, or place the train precisely in a particular position on the track so that the latch plate


111


is located over an operating electromagnet. Furthermore, in order to provide the remote de-coupling, a large electromagnet requiring substantial energy is required in order to overcome the frictional forces resulting from the metal-metal contact between the various elements (e.g., latch pin


109


and housing


104


; housing lock pin


105


and latch member


106


; latch pin


109


and knuckle


101


).




Turning to

FIGS. 12



a


through


12




c


, the conventional solenoid coupler


150


is illustrated. The conventional solenoid coupler


150


was designed to overcome the deficiencies of the conventional mechanical coupler


100


. In particular, the conventional solenoid coupler


150


was developed to allow remote controlled de-coupling operations to take place anywhere on the track. As shown in

FIG. 12



a


, the solenoid coupler


150


comprises a housing


152


and solenoid coil


158


. The conventional solenoid coupler


150


further includes a knuckle


153


, latch plunger


154


, latch plunger spring


155


, knuckle spring


156


and knuckle pin


157


.





FIG. 12



b


illustrates a cross-sectional view of a conventional solenoid coupler


150


in the unlocked open position while

FIG. 12



c


illustrates a cross-sectional view of a conventional solenoid coupler


150


in the locked closed position. Similarly to the conventional mechanical coupler


100


discussed above (see, e.g.,

FIGS. 11



a


-


11




c


), when two couplers


150


are brought together, the respective knuckle arms


153


′ will engage the inner surface


104


′ of the other coupler


150


, causing the respective knuckles


153


to rotate about their knuckle pins


157


.




During initial rotation, the knuckle latch ramp


153


′″ will contact the latch plunger nubbin


154


′, thereby pushing the latch plunger


154


against the latch plunger spring


155


. When the knuckle


153


has rotated a sufficient amount, the latch plunger nubbin


154


′ will be forced by the latch plunger spring


155


into the knuckle latch notch


153


″ and the coupler will be locked in the closed position (shown in

FIG. 12



c


).




With the conventional solenoid coupler


150


, de-coupling is done remotely through electronic control. In particular, the solenoid coil


158


is electrically energized by circuitry in the train, typically a capacitor (not shown), which is driven by the voltage through the tracks. One of the main problems with the conventional solenoid coupler


150


is the amount of voltage required to sufficiently energize the solenoid


158


for driving the plunger


154


. For example, it may take upwards of 12 volts for the solenoid


158


to provide the electromagnetic pull required to move the plunger nubbin


154


′ away from engagement with the knuckle


153


. Additionally, a user would have to put the train in neutral in order to charge the capacitor, and only after the capacitor was sufficiently charged could the coupler be fired.




Accordingly, as discussed above with respect to the conventional mechanical coupler


100


, this results in inefficient, costly power consumption. In cases where the tracks provide the voltage used to energize the solenoid


158


(without a capacitor), a user must provide sufficient voltage on the track to effect a de-coupling operation. However, if the user desires to drive the trains at a slow speed which requires less than 12 volts, the user must speed up the trains by increasing the track voltage solely for effecting the de-coupling operation, and then reduce the track voltage to return to the desired train speed/operating conditions. This results in an inconvenient and repetitive process of speeding up and slowing down trains solely for the purpose of de-coupling trains. Accordingly, there is a need in the art for reducing the voltage required to energize the solenoid


158


.




Turning to

FIGS. 13



a


through


13




g


, the novel coupler


206


of the present invention is illustrated. The coupler


206


includes a coupler body


2061


. The coupler body


2061


has two ends, one end


2061


′ for connecting the coupler


206


to the train and the other end


2061


″ for connecting the coupler


206


to another coupler


206


of a different train. The coupler


206


is driven by a solenoid assembly


41


; however, any conventional driver can be utilized (e.g., DC linear motor). The solenoid assembly


41


includes a bobbin


42


, bobbin wiring


42


′ and bobbin through-hole


42


″, a solenoid back end


43


, a solenoid sleeve


44


(see

FIGS. 13



d


,


13




e


), and a solenoid forward end


45


. The solenoid sleeve


44


surrounds the bobbin wiring


42


′ while the solenoid back end


43


and solenoid forward end


45


close the respective openings at the ends of solenoid sleeve


44


.




The bobbin wiring


42


′ includes at least one lead wire


46


extending therefrom which is connected to the coupler body


2061


via any known suitable means (e.g., soldering). The lead wire


46


receives a voltage from the track in order to provide power to the solenoid assembly


41


. As shown in

FIG. 13



a


, the solenoid assembly


41


is housed in an open portion of the coupler body


2061


.




The coupler


206


further includes a plunger assembly


47


. The plunger assembly


47


includes a plunger


48


, a plunger cap


49


and a plunger spring


50


. The plunger


48


includes an enlarged diameter head portion


48


′ located at one end of the plunger


48


and another enlarged diameter ring portion


48


” located near the one end, thereby forming a groove


48


′″ therebetween. The plunger cap


49


is a hollow ring-shaped member with an inner circumferential surface


49


′ defined therein. Extending radially inward from the inner circumferential surface


49


′ is an annular projection


49


″. Accordingly, the annular projection


49


″ of the plunger cap


49


is tightly fit into the groove


48


′″ of the plunger


48


therefore locking together the plunger cap


49


and plunger


48


. The plunger


48


and plunger cap


49


can also be formed from a single piece of material; however, the manufacturing cost may be increased and/or the benefits of low friction material in the plunger cap


49


may be lost. The integrally formed plunger


48


and plunger cap


49


define a gap


51


located between the inner circumferential surface


49


′ of the plunger cap


49


and an outer circumferential surface of the plunger


48


. The plunger spring


50


functions to bias the plunger


48


/plunger cap


49


toward a knuckle


53


(described below) and away from the solenoid assembly


41


. One end of the plunger spring


50


is seated against the solenoid forward end


45


, and the other end of the plunger spring


50


is guided by the gap


51


to be seated on the annular projection


49


″.




The end


2061


″ of the coupler body


2061


which connects to a coupler


206


of another train includes a knuckle


53


, a knuckle pin


54


, and a knuckle spring


55


. The knuckle


53


includes therein a slot


53


′ whose functionality will be discussed below. The end


2061


″ of the coupler body


2061


further includes two outwardly extending projections


56


,


57


which form a U-shape. The projection


56


has a cut-out portion extending into the projection


56


, thereby defining an opening


58


and two parallel arms


59


,


59


′ (see

FIG. 13



a


). The two arms


59


,


59


′ each have a hole


70


extending therethrough for receiving the knuckle pin


54


. The opening


58


is sized to receive a portion of the knuckle


53


, which portion includes a hole therethrough for receiving the knuckle pin


54


.




Accordingly, the knuckle


53


is attached to the coupler body


2061


by placing the knuckle portion into the opening


58


and inserting the knuckle pin


54


through the respective holes


70


of the two arms


59


,


59


′ and the knuckle portion. The knuckle pin


54


can be fixed to the projection


56


using any suitable fastening means (e.g., washer). The knuckle spring


55


is fitted between the knuckle portion and either arm


59


,


59


′ of the projection


56


for biasing the knuckle


53


towards its open position (i.e., rotated away from the coupler body


2061


). Extending from the other projection


57


is, an inner curved surface


57


′ whose contour effects the coupling of two couplers


206


as will be discussed below.




Operation and the functional relationship between the elements of the novel coupler of the present invention will now be discussed with respect to

FIGS. 13



d


and


13




e


. The knuckle


53


can be in a closed position shown in

FIG. 13



d


or an opened position shown in

FIG. 13



e


. At least one of the couplers


206


needs to be in the open position when coupling of two trains


11


is desired. That is, the knuckle


53


of one or both of the couplers


206


needs to be configured as shown in

FIG. 13



e.






When two trains


11


are ready to be coupled together (i.e., the knuckles


53


of the respective couplers


206


are facing one another), the user enters a command on the hand-held remote control


16


to move one of the trains


11


towards the other (the user could of course also manually bring the trains together). Similarly to the conventional solenoid coupler


150


, as the trains


11


approach one another, the knuckle arms


53


″ of each knuckle


53


pass each other and engage the inner curved surface


57


′ of the other coupler


206


. Accordingly, the knuckles


53


are forced to rotate about their knuckle pin


54


inward against:the bias of the knuckle spring


55


. As the knuckles


53


rotate, the plunger


48


is forced toward the solenoid back end


43


(i.e., the rotational motion of the knuckle


53


forces the translational motion of the plunger


48


). The knuckle


53


slides across the enlarged diameter head portion


48


′ of the plunger


48


as the plunger


48


retreats downward against the bias of the plunger spring


50


.




When the two trains


11


are pushed into each other a sufficient amount, the plunger cap


49


will fall into the slot


53


′ of the knuckle


53


. Accordingly, the plunger spring


50


will force the plunger cap


49


into the slot


53


′. As shown in

FIG. 13



d


, the plunger cap


49


serves as a stop for preventing the knuckle


53


from rotating to the open position through the bias of the knuckle spring


55


. As a result, each knuckle


53


is locked in the closed position, with the respective knuckle arms


53


″ held together in an overlapping manner (see dashed line in

FIGS. 13



b,d


, which represents another coupler


206


). Accordingly, the two trains


11


are coupled together in a simple, one step process of simply moving the trains


11


against each other. In fact, a model train engine or car equipped with an open novel coupler


206


can latch and then unlatch with an open or closed novel coupler


206


, conventional mechanical coupler


100


or conventional solenoid coupler


150


on other train cars.




When the user wishes to de-couple the trains


11


, he/she simply enters the command on the remote control


16


. The remote control


16


sends the command (via TIU


12


) over the track as discussed above to the engine board


20


and processor


200


thereon. The processor


200


receives the de-couple command and in response, pulses the track voltage to the lead wires


46


in order to energize the bobbin wiring


42


′ of the solenoid assembly


41


. Energizing the bobbin wiring


42


′ generates a magnetic field. The magnetic field follows a path around the bobbin wiring


42


′ of the bobbin assembly


42


, through the solenoid back end


43


, the solenoid sleeve


44


, the solenoid forward end


45


, the plunger


48


, and through a minimized gap between the solenoid back end


43


and the plunger


48


(see

FIG. 13



g


).




The magnetic field causes an attraction between the solenoid back end


43


and the plunger


48


thereby pulling the plunger


48


toward the solenoid back end


43


against the bias of the plunger spring


50


. The plunger


48


will continue to move toward the solenoid back end,


43


until the plunger cap


49


engages the solenoid forward end


45


, which serves as a stop for the plunger


48


, or when the knuckle


53


is released from the locked position. The distance between the plunger cap


49


and the portion of the solenoid forward end


45


adjacent to the bobbin


42


is configured to be sufficient to allow the plunger cap


49


to move out of the slot


53


′ of the knuckle


53


. Consequently, the knuckle


53


is forced outwardly away from the coupler body


2061


by the knuckle spring


55


. At that point, the knuckles


53


are in the open position and the trains


11


are allowed to de-couple.




As the knuckle


53


opens, the distance between the projection


57


and the knuckle arm


53


″ increases (see transition from

FIG. 13



d


to


13




e


). As a result, the knuckle arm


53


″ of one coupler


206


has sufficient room to move out of engagement with the knuckle arm


53


″ of the other coupler


206


. Moreover, a second knuckle arm


53


′″ of one coupler


206


further facilitates de-coupling by rotating into the knuckle arm


53


″ of the other coupler


206


in the closed position, thereby pushing the knuckle arm


53


″ out of its closed position. It should be noted that the knuckle configuration of the present invention is such that only one bobbin wiring


42


′ needs to be fired to actuate the de-coupling, although if desired, the bobbin wiring


42


′ of both couplers


206


could be fired.




The coupler


206


of the present invention operates at significantly less voltage than the prior art due to its unique structure and mechanical connections. The present invention contemplates that the amount of voltage necessary to fire the couplers is approximately 6 volts, or about half the amount of voltage necessary in the conventional solenoid coupler


150


. As a result, the coupler


206


can be opened at minimal track voltage without the need to first increase the track voltage to a sufficient amount, or to place the train in neutral and use charged capacitors to provide sufficient voltage to operate the coupler mechanism, as was required by the prior art.




Turning to

FIGS. 13



f


and


13




g


, the structural differences between the novel coupler


206


(

FIG. 13



g


) and the conventional solenoid coupler


150


(

FIG. 13



f


) which give rise to the differing voltage requirements will now be discussed. Both couplers draw voltage from the track to energize their respective solenoids for producing a magnetic field comprising magnetic flux lines. The magnetic flux lines run through the plunger to create a pull on the plunger in the direction of the magnetic flux lines. The more flux lines produced and the more dense those flux lines are, the more magnetic pull applied to the plunger. Ideally, all flux lines should run through the plunger in order to optimize the full pull force. available from the magnetic flux lines created by the solenoid. Accordingly, the novel coupler


206


of the present invention was designed and configured to increase the amount and density of magnetic flux as well as to create a magnetic circuit that maximizes the amount of flux lines that run through the plunger (as opposed to outside of the plunger).




In order to increase magnetic flux, the novel coupler


206


provides an improved “magnetic circuit” that incorporates ferromagnetic material. Specifically, each of solenoid sleeve


44


, solenoid forward end


45


, plunger


48


and solenoid back end


43


are made from ferromagnetic material (preferably, steel) for conducting the magnetic flux lines in an intimate closed circuit. Accordingly, a greater number of magnetic flux lines that are more closely spaced (i.e., more dense) are produced. Furthermore, as the solenoid forward end


45


surrounds the majority of the plunger


48


, the closed magnetic circuit produced by the configuration of the aforementioned elements of the novel coupler


206


increases the number of flux lines that run through the plunger


48


.





FIG. 13



g


illustrates generally the magnetic flux lines produced by the novel coupler


206


of the present invention (the thickness of the sleeve


44


has been exaggerated to better illustrate the sleeve's ability to contain essentially all the flux lines within its thickness). In contrast, turning to

FIG. 13



f


, the magnetic flux lines produced by the conventional solenoid coupler


150


are both smaller in amount and more diffuse (i.e., less dense), resulting in a less-efficient conversion of voltage to magnetic pull. In addition, some of the flux lines run outside of the plunger


154


(adjacent the plunger nubbin


154


′), thereby wasting a portion of the magnetic pull created by the solenoid wiring


158


.




Several factors contribute to this deficiency in the conventional solenoid coupler


150


. Foremost among them is the lack of ferromagnetic material for conducting the magnetic flux lines. The only ferromagnetic material found in the conventional solenoid coupler


150


is in the plunger


154


. The housing


152


is made from non-ferromagnetic material (e.g., zinc). Furthermore, there is no sleeve, solenoid forward end, or solenoid back end to form a closed magnetic circuit around the solenoid wiring


158


. Accordingly, as there is no structural boundary for which to contain the magnetic flux lines, leaving only air as the magnetic conductor (which is highly inefficient), the resulting magnetic flux lines are diffused about a greater area surrounding the conventional solenoid coupler


150


. Therefore, as shown in

FIG. 13



f


, the magnetic flux lines produced in the conventional solenoid coupler are far fewer and less dense than those produced in the novel coupler


206


of the present invention shown in

FIG. 13



g


. Because the end. portion of the plunger


154


(including plunger nubbin


154


′) is not surrounded by a ferromagnetic material (which would have extended more of the magnetic circuit through the plunger


154


), some flux lines are lost from the plunger


154


in the conventional solenoid coupler


150


, as shown in

FIG. 13



f


(flux lines moving away from plunger


154


before running completely through plunger


154


).




As a result of the structural distinction between the novel coupler


206


of the present invention and the conventional solenoid coupler


150


, the novel coupler


206


will produce significantly more magnetic pull with the same amount of applied voltage. It follows that the novel coupler


206


will require less voltage than the conventional solenoid coupler


150


to produce the same magnetic pull. For example, if it takes 12 volts to provide the needed magnetic pull for moving the plunger


154


out of engagement with the knuckle


153


(thereby effecting a de-coupling operation) in the conventional solenoid coupler


150


, it would take only about 6 volts in the novel coupler


206


.




Moreover, the aforementioned difference in voltage requirements between the conventional solenoid coupler


150


and the novel solenoid coupler


206


is based on the assumption that the various mechanical interactions (e.g., plunger sliding on bobbin/housing, knuckle/plunger interface, etc.) result in the same frictional resistance in both couplers.




However, another advantage of the novel coupler


206


is the elimination of metal-to-metal contact, which decreases wear/tear (improving reliability) as well as decreasing the frictional forces that the magnetic pull needs to overcome for de-coupling the coupler. The conventional solenoid coupler


150


does not include a bobbin and therefore the solenoid wiring


158


is wrapped directly around the metal (e.g., zinc) housing


152


. As a result, the steel plunger


154


is in bearing contact with the inner surface of the housing


152


. This metal-to-metal contact increases the resistive frictional forces, thereby increasing the amount of magnetic pull needed to pull the plunger, as well as adding to the wear/tear of both the plunger


154


and the inner surface of the housing


152


.




In contrast, the novel coupler


206


incorporates a spool-like Acetal plastic bobbin


42


which holds the bobbin wiring


42


′ around its outer surface. It should be appreciated that any low-friction plastic may be used (e.g., Nylon). Accordingly, the metal plunger


48


is in bearing contact with the plastic inner surface of the spool-like bobbin


42


within the bobbin through-hole


42


″, resulting in less wear/tear and frictional resistance.




Similarly with respect to the knuckle/plunger mechanical interaction, the conventional solenoid coupler


150


incorporates metal-metal contact (steel plunger nubbin


154


′ and zinc knuckle


153


). In contrast, the plunger cap


49


of the novel coupler


206


is made from low-friction plastic (Acetal, Nylon, etc.), thereby inducing a plastic-metal contact between itself and the knuckle. As a result, the novel coupler


206


greatly reduces the wear/tear and frictional resistance resulting from the mechanical movements within the coupler


206


.




Other improvements and advantages of the novel coupler


206


will now be discussed. The solenoid forward end


45


serves other important functions in addition to completing the magnetic circuit for the flux lines. In particular, the solenoid forward end


45


serves as a bearing for the plunger cap


49


, thereby guiding movement of the plunger assembly


47


. The solenoid forward end


45


may be configured with an inner diameter slightly larger than the diameter of the plunger


48


in order to prevent bearing metal-to-metal contact therebetween, further reducing friction and wear. As a result of the bearing contact between the plunger cap


49


and solenoid forward end


45


(which is also a plastic-metal interface for reducing frictional/wear), any side thrust force exerted on the plunger


48


from the coupling operation will be absorbed at the end of the plunger


48


(as opposed to the portion of the plunger


48


just outside of the bobbin


42


). This dramatically reduces any bending movement applied to the plunger


48


which would otherwise damage the plunger


48


over time. In addition, the solenoid forward end


45


acts as a locating feature for mounting the bobbin


42


onto the coupler body


2061


. These combined functions of the solenoid forward end


45


reduce tolerance buildups in the overall design of the novel coupler


206


. Even further, the configuration of the solenoid forward end


45


provides the capability to exclude the plunger spring


50


from the magnetic path (by functioning as a spring seat outside of the magnetic path; see

FIGS. 13



d


,


13




e


), thereby allowing the magnetic path to incorporate as much steel as possible. However, in the conventional solenoid coupler


150


, the plunger spring


155


is positioned within the housing


152


. This displaces steel from the magnetic circuit (e.g., by displacing a solenoid back end) of the conventional solenoid coupler


150


, which contributes to fact that the magnetic path in the conventional solenoid coupler


150


is essentially all air (except for plunger


154


). As discussed above, the solenoid back end


43


of the novel coupler


206


closes the magnetic circuit and increases the amount of metal (e.g., steel) in the magnetic circuit (thereby increasing magnetic flux). As an additional enhancement for the magnetic flux, the solenoid back end


43


includes a conical end shape


43


′ that receives a corresponding conical end portion of plunger


48


. This configuration further minimizes air gaps in the magnetic circuit.




The plunger cap


49


provides several important functions, some of which include: (1) acting as a seat and pocket for the plunger spring


50


, (2) acting as a bearing for the end of the plunger assembly


47


contacting the knuckle


53


, (3) acting as a stop for the plunger assembly


47


when the bobbin wiring


42


′ is energized (importantly, this function prevents contact between the plunger


48


and solenoid back end


43


, which could otherwise allow residual magnetic fields to keep the plunger


48


in the energized position; i.e., precluding the ability to lock the knuckle


53


in the closed position), and (4) acting as the surface which latches into the slot


53


′ of the knuckle


53


. It is preferred that the plunger cap


49


be made of a one-piece construction, thereby minimizing parts and tolerances. The hole through the bobbin


42


serves as a bearing for the plunger


48


. Thus, the plunger


48


motion is guided by plastic bearings, avoiding metal-to-metal contact with its consequential high friction forces and wear. It is further preferred that the plunger cap


49


and bobbin


42


be made from Acetal Plastic or other low friction, high impact plastic (including but not limited to Nylon), thereby minimizing friction in the bearing and latch functionality resulting in a further reduction in the voltage required to energize the bobbin wiring


42


′.




In summary, the coupler


206


of the present invention provides significant advantages over the conventional prior art couplers for several reasons. In particular, the construction of the coupler


206


of the present invention greatly reduces the frictional forces between the moving parts resulting from the locking and unlocking of the knuckle


53


into and out of coupling position. Accordingly, the coupler


206


avoids the wear and tear inherent in the prior art couplers


100


and


150


. The steel back end


43


, sleeve


44


and front end


45


form a magnetic path with the plunger


48


which greatly enhances the flux generated in the bobbin wiring


42


′, compared to the prior art solenoid coupler


150


. The combination of low friction and efficient magnetic path allow the novel coupler


206


to operate under much lower voltage than the prior art. The novel configuration of the coupler


206


of the present invention therefore provides significant advantages over the prior art both in its structure and its function.




SMOKE/STEAM UNIT




Yet another feature of the present invention is a new smoke/steam unit design. Various methods exist in the prior art for producing puffs of “smoke” or steam from the model train, in an effort to depict a real train working as it moves down a track. This application will refer to the “smoke unit” hereafter, although it should be understood that the same design and principles apply to “steam.”




Turning to

FIGS. 14



a


through


14




c


, an exemplary novel smoke unit


144


of the present invention will be described. The smoke unit


144


includes two resistors


80


,


81


, fiberglass material


82


, an oil substance


83


, and a fan


84


. One resistor


80


can also be used, preferably in combination with a biasing member


87


(as shown in

FIG. 14



b


), but two resistors will more securely hold the fiberglass material. The smoke unit


144


produces smoke by supplying the resistors


80


,


81


with track voltage. Consequently, the resistors


80


,


81


heat up and vaporize the oil substance


83


to produce the smoke while the fan


84


“puffs” out the smoke from the train.




The quantity of smoke outputted by the smoke unit


144


is directly related to the power applied to the resistors


80


,


81


. That is, the more voltage applied to the resistors


80


,


81


, the more smoke will be outputted. The smoke unit


144


can be controlled in two modes, manual and automatic. The user can select in which mode to operate by inputting the desired mode on the remote control


16


. In manual mode, the user will input on the remote control


16


one of, for example, three possible quantities of smoke: high, medium, and low (it should appreciated that any number of quantities of smoke can easily be programmed into the processor). Accordingly, at any time during operation for any train(s), the user can initiate a smoke output.




For example, if the user wants one of the train(s) to puff a high quantity of smoke (e.g., when climbing a hill, implying the engine is working hard), the user first inputs the digital address of the desired train(s) (or, if the user desires all the train(s) to output the smoke, then he/she can go directly to the next step without indicating a particular train). Next, the user enters the quantity of smoke desired (low, medium, and high) into the remote control


16


.




The remote control


16


sends the request via RF signals to the TIU


12


, which in turn sends the request to the track


10


. The signal from the TIU


12


searches for the selected train(s) via the digital address. The processor


200


on the engine board


20


of the train(s) will interpret the signal as a request for a low, medium, or high quantity of smoke.




The processor


200


adjusts the amount of voltage applied to the smoke unit


144


, and thereby the quantity of smoke, by using a smoke system driver circuit


205


(see

FIGS. 4 and 14



c


) that comprises a pulse width modulator circuit


85


to adjust the time that voltage is applied to a resistor circuit driver


88


, which controls the voltage applied to the resistors


80


,


81


. The fan


84


will be turned on via a fan motor drive circuit


89


, to puff out the smoke. Accordingly, the smoke unit


144


will be able to produce the needed smoke independently of the track voltage. For example, if the track voltage is high but the request for smoke is low, the processor


200


will adjust the power applied to the resistors


80


,


81


by pulse width modulating the track voltage to decrease the time the voltage is applied to the resistors


80


,


81


. Similarly, if the track voltage is low (e.g., in “Conventional” or “Legacy” mode, where the train(s) are moving at slow speeds), the pulse width modulator


85


will increase the time the voltage is applied to the resistors


80


,


81


. Alternatively, the voltage applied to the resistors


80


,


81


could also be controlled by using a linear voltage regulator (not shown).




Another novel feature of the present invention is the fast response time of the smoke system driver circuit


205


. The smoke system driver circuit


205


of the present invention uses an electronic brake (not shown) located in the fan motor drive circuit


89


to quickly stop or start blowing the smoke out of the smoke unit


144


. In particular, the electronic brake is a FET (not shown) that is placed across the fan motor that will short out the motor when the user commands the smoke unit


144


to stop blowing smoke. As an alternative, the processor


200


can also be programmed to momentarily reverse the voltage on the motor to stop the fan


84


even quicker. Accordingly, the smoke unit


144


will immediately stop or start blowing smoke at the user's command. In another embodiment, the fan


84


would run continuously and a valve or shutter could be used to stop the airflow at the desired time, thereby stopping the flow of smoke.




In automatic mode, the novel smoke system driver circuit


205


of the present invention will control the smoke unit


144


according to the speed and load of the train(s) in order simulate a realistic steam and/or diesel train. In other words, the smoke will be outputted automatically at a rate and quantity that matches the current condition of the train(s), similarly to what takes place in a real-life train.




The rate at which the smoke is “puffed” out is dependent on the speed of the train(s). There are various types of trains, each having distinct qualities with respect to their respective smoking systems. A steam engine train will output discrete “puffs” of smoke in response to the revolutions on the wheel. For example, for every ¼ turn of a wheel, the smoke unit


144


would output one “puff” of smoke (of course, the processor


200


can be programmed, via the remote control


16


, to any correlation between the wheel revolutions and the number of “puffs”). In contrast, a diesel engine train outputs smoke at a continuous rate. The smoke unit


144


of the present invention works under both conditions (discrete vs. continuous).




Accordingly, in steam engine mode (which can be selected using the remote control


16


), the processor


200


will control the on/off switching rate of the fan


84


based on the output of the speed sensor


2073


. The speed sensor


2073


, as discussed above, is a direct measure of the revolutions per minute (“rpm”) of the wheels of the train(s). Accordingly, if the speed sensor


2073


indicates that the wheels are turning at 100 rpm, then the processor


200


will command the fan


84


of the smoke unit


144


to turn on and off at 400 times/minute (100 revolutions * 4 “puffs” per revolution). In diesel mode, the processor


200


will use steady state control of the fan


84


, as opposed to on/off switching, to gradually increase the rate the smoke is outputted as the speed of the train increases. This is accomplished by the PWM


85


(see

FIG. 14



c


).




The operation of the smoke unit


144


in automatic mode with respect to the quantity of smoke will now be discussed. In order to obtain the quantity of smoke to be output by the smoke unit


144


, the processor


200


will determine the load on the motor


2072


of a train(s) by calculating the power that is currently required to move the train(s) at a given speed. The calculated result is then compared to the “normal” power required to move the train(s) at the given speed, which “normal power” is stored in flash memory


209


for the particular motor on the engine board


20


. This comparison will indicate to the processor


200


whether the motor


2072


is requiring more power or less power than normal to run at the current speed. Accordingly, the processor


200


will implicitly know the load on the motor


2072


of the train(s). The processor


200


will then automatically operate the smoke unit


144


according to the load on the motor


2072


.




An example will better illustrate how the smoke unit


144


controls the quantity of smoke in automatic mode. As discussed above, a user initiates operation by inputting on the remote control


16


the desire for the system to be in automatic mode for the smoke unit


144


. Accordingly, when the train is running under normal conditions, the comparison of the “normal” power consumption of the motor


2072


at a given speed and the actual power consumption of the motor at the given speed will have a one-to-one ratio.




However, when the train goes up a hill, although the speed will remain the same as a result of the novel speed control system of the present invention and therefore the rate of puffs will not change, the power inputted into the motor will increase (which will be sensed by a voltage sensor for example) by virtue of the increased duty cycle. Accordingly, the processor


200


will deduce that the load on the motor


2072


has increased. As a result, the processor


200


will command that more voltage be applied to the resistors


80


,


81


by increasing the duty cycle via the pulse width modulator circuit


85


(the fan


84


will remain at the same rate because the train is moving at the same speed). The resistors


80


,


81


will get hotter and thereby release a more dense “puff” of smoke. Similarly, when going down hill, the reduced load on the motor


2072


is sensed, the duty cycle reduced, and the resistors


80


,


81


will get less hot and thereby release a less dense “puff′ of smoke. The density of smoke will be output in the same fashion regardless of being in diesel mode or steam engine mode.




BRAKE AND CRASH SOUNDS




Some other features of the present invention are now described. The processor


200


can be directed by the user via the remote control


16


to automatically retrieve, for example, a brake sound when the train slows down at a given rate. For example, if the track voltage (reflecting user's desired speed) in “Conventional Mode” is reduced at a rate faster than 5 MPH/second, the processor


200


will sense the deceleration using the feedback from the speed sensor


2073


and thereby retrieve the requisite sound file to play a “braking” sound. As another example, if the contact between the roller (not shown) of the train(s) which rolls on the charged center rail is lost, for example if the train is derailed (i:e., speeding too fast around a corner, etc.), the processor


200


can be programmed to retrieve a “crash” sound stored in the flash memory


209


.




DOPPLER EFFECT FEATURES




Each of the sounds played through the train speaker


208


” can be modified to incorporate the Doppler Effect. A description of the Doppler effect characteristics of the present invention:will now be provided. The Doppler effect is a well-known principle that represents the change in pitch and volume that results from a shift in the frequency of the sound waves as evidenced by the sound of an approaching object. A common example of the Doppler effect is experienced when an ambulance or fire truck approaches. As the vehicle approaches an observer, the sound waves from the siren are compressed towards the observer. The intervals between the sound waves diminish, which results in an increase in the frequency or pitch of the siren. As the vehicle recedes past the observer, the sound waves are stretched relative to the observer, causing a decrease in the pitch of the siren. Thus, by listening to the change in pitch of a siren, the observer is able to determine if the vehicle is approaching or speeding away.




The most basic implementation of the Doppler effect in the present invention will be referred to as a “Doppler run.”

FIG. 16



a


graphically depicts the Doppler run mode. The user sets the volume of the train sounds at some maximum arbitrary level, such as 75 dB (this is a non-limiting example only) from the remote control


16


. As the model train cycles around the tracks, the user enters the command for a Doppler run. This is based on a fixed distance that the train travels, and can be pre-programmed to any reasonable distance. As one example, assuming the model track layout is approximately 25 feet of track, the fixed distance could advantageously be programmed to be 25 feet.




Once the. user enters the Doppler run command, the volume of the train immediately drops to a fixed attenuation level, for example, 40 dB. The train processor


200


then monitors the distance the train travels (speed versus time) and causes the sound output from the train to rise from the 40 dB level to the maximum arbitrary level of 75 dB. The maximum volume level is obtained at approximately the mid-way point of the fixed distance (in the above example, at approximately 12.5 feet). The sound then drops back to the attenuated level of 40 dB, which is reached when the train completes the fixed distance (in the given example, at the point where 25 feet of track has been traversed). The pitch of the sound behaves in the same fashion, and is a function of the real-time speed of the train.




The Doppler run command allows a user to simulate the real-life Doppler effect on the model train track layout


10


. For example, assume that the user has an observer stationed at one end of the track. At the point when the train is the farthest away from the observer, the user enters the Doppler run command. The sound of the train will immediately drop to the attenuated level and shift the pitch according to the speed of the train, giving the observer the effect that the train is far off in the distance. As the train approaches the observer, the sound increases until the point when the train passes the observer, at which point the maximum volume is reached. The pitch of the train increases as it approaches and then drops to a zero shift at the point when the volume is maximum. Once the train passes the observer, the sound immediately begins to decrease and the pitch is at a negative frequency shift (see

FIG. 16



d


). Thus, the observer is left with a sense of the real Doppler effect, as the train whooshes past the observer. The observer hears the oncoming sound followed by the receding fade in the same manner as a person standing by a real set of train tracks.




The next embodiment of the Doppler effect in the present invention is called the “Doppler repeat.” This mode of operation is graphically depicted in

FIGS. 16



b


and


16




c


. The user enters a “Mark Start” command on the remote control. This resets an internal odometer inside the model train. The odometer accumulates the distance travelled by the train until the user enters a “Mark Repeat” command on the remote control. The accumulated distance from Mark Start to Mark Repeat is the “Doppler loop.”




In operation, the user then enters the Doppler repeat command. The volume immediately drops to the far-off attenuation level, for example, 40 dB, and the pitch shifts according to the train speed. The model train processor then calculates the required distance for causing the Doppler peak to occur at the Doppler loop point. The volume will thereafter peak at every Doppler loop distance travelled, and the pitch shift will demonstrate the characteristics shown in

FIG. 16



d


, until the user turns off the Doppler repeat command.




CHUFF SOUNDS




Similarly to the smoke unit


144


, the sound system circuit


208


can be programmed to automatically output sounds corresponding to the condition of the train(s)


11


. Specifically, every time the processor


200


sends a “puff” signal to the smoke system driver circuit


205


in response to the feedback of the speed sensor


2073


, the processor


200


will simultaneously retrieve from the flash memory


209


a “chuff” sound file. This chuff sound file is sent to the sound system circuit


208


. Accordingly, for every “puff” of smoke there will a “chuff” of sound, both corresponding to the speed of the train.




Further, there are three possible “chuff” sounds reflective of the load on the train(s): constant (normal), labored “chuff” and drift “chuff”. Again, with respect to the load on the train(s), the sound system circuit


208


will respond via the processor


200


to the load measurements on the motor


2072


in the same fashion as the smoke system driver circuit


205


. That is, if for example the train


11


is going up a hill, the processor


200


will sense the increase in load and will thereby alter the sound to reflect a “labored” chuff sound. In the same way, if the train(s) is going down a hill, the processor


200


will sense the decrease in load and will thereby alter the sound to reflect a “drift” chuff sound. In addition, the “labored” and “drift” chuff sounds can be utilized in the “conventional” or “legacy” mode of operation in the following manner: whenever track voltage is increased, “labored” chuffs will be played, and conversely, whenever track voltage is decreased, “drift” chuffs will be played.




LIGHT CONTROL




The light driver circuit


204


includes a pulse width modulator (not shown) in order to maintain the same brightness regardless of the track voltage to thereby attain the realism associated with a real-life train (i.e., a real-life train does not regulate its light output dependent on power to the engine). Of course, it is also contemplated that a user could obtain a desired brightness and colors by entering the command on the remote control


16


.




ACCESSORY INTERFACE UNIT




Turning,to

FIGS. 17



a


and


17




b


, the AIU


18


will be discussed in greater detail. The AIU


18


functions to control operation of any of the accessories (examples provided below) included in the track layout


10


(it should be noted that the AIU


18


can also be coupled to accessories not within the immediate track layout


10


; e.g., a gas station around the periphery of the track layout


10


). The AIU


18


can be powered by any suitable means, including, but not limited to, a transformer connected to a standard wall outlet (not shown) (this can be same as the transformer the powering track), or a battery. The AIU


18


is coupled to the TIU


12


(see

FIG. 17



a


) via an input


180


. The connection between the AIU


18


and TIU


12


can also be any known suitable means, including, but not limited to, a phone line or a conventional power line. The difference between the two examples (phone line or conventional power line) lies in the type of communication signal (fiber optic phone signal or voltage at given frequency) that will be sent to the AIU


18


from the TIU


12


.




The AIU


18


further includes a set of output relays


181


which are coupled to various portions of the track layout


10


through standard hard wiring (i.e., voltage/current carrying lines). Accordingly, the AIU


18


can be connected to a wide range of accessories in any configuration desired by the user, details of which will be discussed below.




The AIU


18


functions to operate the various accessories (i.e., turn on/off) in response to user commands on the remote control


16


. Specifically, when a user enters a command to turn on a street light, for example, the remote control


16


will output an RF signal to the TIU


12


. In turn, the TIU


12


will output the command via the connection (phone line or conventional power line) to the AIU


18


. The AIU


18


will then switch on/off the appropriate relay


181


coupled to the selected accessory to thereby turn on/off power to the selected accessory.




When a user first connects the AIU


18


to the track layout


10


, he/she has the option to select any combination of accessories to be simultaneously switched with each respective relay


181


. For example, the user can couple one relay


181


to a series of street lights (see

FIG. 17



a


) distributed throughout the track layout


10


. In addition, the user can couple another relay to a track switches for changing the train path in the layout


10


. Accordingly, the user can couple each of the relays marked, for example, 1-20, to a different series of accessories. Moreover, the combinations are not limited to the same type of accessories for each relay


181


. In other words, a single given relay


181


can be coupled to a street light, a crossing gate, and a track switch. It is quickly apparent that the number of combinations are endless, thereby limiting the user in creating a personal track layout


10


only to the extent of his/her imagination.




Once the user couples the desired relays


181


to the respective accessories throughout the track layout


10


, the user will then store into memory (either TIU flash memory


125


or remote control flash memory


163


′) the respective configuration. For example, if a user couples relay #


1


to all the street lights in the track layout


10


, the user will then input into the remote control


16


that relay #


1


will turn on all street lights.




The remote control


16


includes push-buttons


162


with alphanumeric characters printed thereon. Accordingly, when programming a particular relay


181


, the user will be able to name the respective category of accessories that the particular relay


181


will switch on. The user can then store in memory the specific name the user chooses to identify each configuration. That way, the user can simply scroll through the stored names using the thumb-wheel


161


on the remote control


16


, and select the name which matches the accessories the user wants to turn on. For example, let's assume a user couples relay #


1


to all the street lights, relay #


2


to the track switches on the southern part of the track layout


10


, and relay #


3


to all the crossing gates on the track layout


10


. Using the push-buttons


162


with the alphanumeric characters printed thereon, the user can then spell out and .store the names “All street lights” corresponding to relay #


1


, “Southern track switches” corresponding to relay #


2


, and “All crossing gates” corresponding to relay #


3


.




Anytime the user wants to operate, for example, the track switches located on the southern part of the track layout, he/she need only scroll through the stored list of “named” relays and select “Southern track switches”, and the TIU


12


will send the appropriate signal to the AIU


18


corresponding to the selected relay


181


, thereby powering and switching the track switches on the southern portion of the track layout


10


.




Each relay


181


has a corresponding switch that is configured to be turned on/off based on the output signal from the TIU


12


. For example, if a conventional power line is used for the connection between the AIU


18


and the TIU


12


, then each relay


181


can be activated, and therefore identified, by a distinct voltage frequency. For example, if the user commands relay #


1


to turn on, the TIU


12


will send out a voltage at 50 Hz, whereas if the user commands relay #


2


to turn on, the TIU


12


will send out a voltage at 100 Hz. Accordingly, a different frequency will be applied to the AIU


18


from the TIU


12


, depending on which relay


181


is commanded to be turned on. A three wire serial interface connection between the TIU


12


and AIU


18


may also be used, wherein one wire is a data line that is set to the value of the most significant bit of the data byte being sent. A clock line is then pulsed high then low to clock in the signal into an 8 bit shift register in the AIU


18


. After 8 bits have been clocked in, the entire byte is clocked out by pulsing the third line, which is a latch. The data in the byte is therefore essentially 7 bits of address to get to the particular relay in the AIU that the user wishes to open or close and 1 bit to determine if the relay is being opened or closed.




Of course, various other “identifying” means can be used such as voltage amplitude, fiber optic signals (phone line connection), etc. The general concept remains the same; that is, each relay


181


will be configured to be triggered (i.e., turned on/off) by a “identification signal” sent from the TIU


12


in response to a user command to turn on a particular accessory.




As shown in

FIG. 17



b


, it is contemplated that any number of AIUs


18


can be used for the track layout


10


of the present invention, although power constraints from the TIU


12


may limit the number of AIUs that can be connected to a single TIU


12


. Up o five AIUs connected to a single TIU has been tested successfully at the present time, although it is anticipated that this number will improve in the future. Accordingly, a user can obtain a large number of relays


181


needed for creating the desired combinations of accessories that are to be turned on/off together. Along the same line, a plurality of TIUs


12


can also be coupled to the track layout


10


, which is made possible by its unique electrical configuration. With any given set-up (e.g., AIUs


18


and TIUs


12


), the user simply will identify and store the relays


181


into memory. It is clear that relay #


1


of AIU #


1


can easily be differentiated from relay #


1


of AIU #


2


by simply coding relay #


1


of AIU #


2


as relay #


21


(on the assumption that AIU #


1


has 20 relays).




It is contemplated that the AIUs


18


will have multiple inputs that can be monitored by the TIU


12


. For example, infrared switches (so-called “infrared track activation devices (ITAD)”) or mechanical contact switches may be connected to the AIU


18


. When such a switch is opened or closed, a signal is passed from the AIU


18


to the TIU


12


so that the TIU


12


can activate a related action. For example, an ITAD (which function's as an infrared motion detector) may be placed near the track and wired to the AIU


18


such that when a train passes, the ITAD switches and this action is then passed to the TIU


12


. The TIU


12


, now knowing where the train is on the track, could then activate a crossing gate located elsewhere on the track. Any number of connection possibilities can be achieved in accordance with this feature of the present invention. For simplicity's sake, only one input to the AIUs


18


are shown in the figures.




The SCS of the present invention provides the user with a wide range of accessories for incorporation into the track layout


10


to further the conception of realism exuded. by the track layout


10


. For example, a user may add an accessory such as a passenger station with “people” waiting to board the approaching train, which will change into an empty passenger station after the “people” have boarded the train and the train moved on. By wiring the passenger station to an AIU


18


, the user can operate a motor (not shown) to move the panel holding the passengers behind the roof of the station when a train leaves the passenger station, thereby creating a realistic portrayal of a true passenger station). Similarly, a freight station is also contemplated by the present invention, where cargo replaces the passengers. The operation to “hide” the cargo when a train leaves is similar to the passenger station.




It should be appreciated that many other types of accessories may be used with the present invention, including, but not limited to, houses with internal lighting, drive-thru restaurants, lights along the track, crossing-gates, flashing barricades, track switches (where two distinct tracks, indicating different paths, come together into one track and the track switch determines which track the train will go on), bridges with lighting, water towers, fire houses with fire-trucks that go in and out from the track layout


10


, billboards with speaker announcements, . . . etc.




COMMAND RECORD




Another aspect of the present invention is the “record mode” for recording a list of commands inputted on the remote control


16


to be played back at a later time. A user can push a designated push-button


162


on the remote control


16


to initiate “record mode”. Thereafter, the user can input any command (including actuation of any accessories) to drive the track layout


10


. For example, the user can input a desired speed of 10 smph for two trains on the track in “command mode” of operation, a desired speed of 7 smph for the remaining trains on the track in “conventional mode”, firing couplers, playing music, switch track switches, turn on street lights, etc. Each command inputted in the remote control


16


will be stored in the flash memory


125


of the TIU


12


(or alternatively, the commands can be stored in the flash memory


163


′ of the remote control).




When the user has finished his/her desired chronology of commands, the user will then push the appropriate push-button


162


to “stop recording”. The user can then name the file and save it in a fashion similar to saving file names with respect to the accessories discussed above. Accordingly, the user will be able to “play-back” the commands at any time in the future by simply activating the stored file. This is done by scrolling through the remote control


16


using the thumb-wheel


161


and finding the file identified by the name given to it (e.g., “My favorite commands”). By activating the desired file name, the remote control


16


will then send the appropriate RF signal to the TIU


12


, which will retrieve from its flash memory


125


the desired file and will automatically play back the list of commands as they were saved!




Saving commands in “record mode” can be accomplished in many modes. One mode is during actual real time operation. That is, while “record mode” is on, the user can input commands and operate the track layout


10


under normal conditions. The remote control


16


will function to operate the track layout in real time while simultaneously directing the TIU


12


to store each command, exactly as inputted in real time with the same time delay between commands, into its flash memory


125


. When the user desires. to stop recording, he/she simply presses the appropriate push-button


162


and thereafter names the file. At which point, the commands, as their were entered, will be stored in the flash memory


125


of the TIU


12


under the given file name. The user is then free to continue operating the track layout


10


.




In another mode, the user can also “record” commands without operating the track layout


10


. This provides many benefits, one of which is illustrated with the following example. Assume a daughter wants to surprise her mom for her birthday by playing “happy birthday” through the speaker


208


″ of one of the trains (via, e.g., a CD player) while driving the train towards her mom as she enters the room. If she was required to operate the train before the mom entered, the surprise would be ruined as the mom would hear the train moving.




Accordingly, the present invention allows the user to “record” into files several sets of commands very quickly and efficiently, as well as quietly (which will allow a user to continue “recording” during late night hours while others are sleeping). Even further, if a user desires to input certain time delays between commands (e.g., turning on 10 street lights at 10 minute intervals), the user can do so without waiting 100 minutes during actual operation to record such a command set.




Recording without operating the track layout can be accomplished in various manners. Most simply, the transformer could be physically de-coupled, or the TIU


12


could be physically de-coupled from the track layout


10


. Alternatively, the TIU


12


can be commanded, via the remote control


16


, to operate under “ignore mode”. In “ignore mode”, the TIU


12


will receive the entered commands from the remote control


16


and will save them in the flash memory


125


as discussed above, but will not forward the commands onto the track layout


10


and/or AIU


18


. This can be effected by activating an open circuit, for example, via a transistor so that the TIU


12


is electrically de-coupled from the track layout


10


and/or the AIU


18


.




TIU POWER




Another aspect of the present invention is the capability to operate with any type of power source′ (i.e., power source


14


) for powering the track layout


10


. This capability is provided by the novel electrical configuration of the TIU


12


. The TIU can be configured with multiple voltage inputs and voltage outputs. The voltage inputs may be fixed and/or variable′. Similarly, the voltage outputs may be fixed and/or variable.




Accordingly, the TIU


12


is capable of receiving voltage from both DC (fixed) and AC (variable) power supplies. Thus, the SCS of the present invention can be operated by any commercial power source. Moreover, the TIU


12


is capable of receiving a fixed voltage regardless of the type of power source (e.g., an AC power source connected to a fixed voltage input will be converted to DC or to a different AC value). In the same manner, a received fixed voltage input can be converted to a variable output, thereby allowing the TIU


12


of the present invention to control track voltage independently of the power source


14


. This allows the more archaic power sources that do not have RF capability (i.e., can not receive and transmit RF signals thereby not being capable of communicating directly with the remote control


16


) to operate with the same features enjoyed using a power source


14


with RF capability. That is,.a user can alter track voltage without needing to manually adjust the power source (e.g., manipulating a throttle on the power source). Moreover, with fixed voltage power sources, like a battery, previous TIU units would require replacing the battery for every different track voltage desired, which it can be quickly appreciated is impractical to say the least. By making the appropriate connections to the TIU


12


of the present invention, a single battery can be used while still enjoying the wide range of features of the present invention which require varying track voltage (e.g., changing speeds in legacy and conventional mode).




OPERATING EXAMPLE




An example of the range of features and capabilities of the present invention will now be provided. This example is illustrative, not exhaustive.




A model train layout is connected as shown in

FIG. 1. A

model train is placed on the track. The user turns the power source up to full and leaves it there, indicating that the user is interested in operating in “command mode.” Once the track is powered up, the trains automatically enter Command mode. The model train sends a data packet containing information about the model train (address, operating conditions, etc.). This information is retrieved by the user through the remote control and shown on the display unit (if desired).




Once powered up, the TIU regularly sends out a “watchdog” packet to the trains. If these watchdog packets are present on the track, the trains assume that Command mode remains the default mode. In the event the train ceases to receive the watchdog packets, the train assumes the user wishes to operate in conventional mode and disables the ability to receive Command mode commands. By this feature, each model train may be selected and “started up” independently. All model trains equipped with the engine board


20


are always “listening” to the track for data packets addressed to them, even when the trains appear to be dormant on the track.




The user is now ready to operate the train. The user first decides to turn on and test the train lights. By either pressing a button on the remote control dedicated to a particular light control, or scrolling through the commands on the remote control displayed on the display unit, the user turns on (and/or off) the various lights located on the model train, such as the head lights, marker lights, ditch lights, beacon lights, and cab interior lights. The light functions are independent of any train movement.




Next, the user decides to turn the model train's engine on. This is accomplished by entering the train address and the command “engine on” through the remote control. The model train responds with authentic “engine start-up” sounds. The user now desires the train to begin to traverse the track. The user enters a scale mile-per-hour command, and, if desired, an acceleration rate at which the user wants the model train to reach the desired scale mile-per-hour. For example, if the user wants the train to very slowly reach. the desired speed, the user may enter a slow acceleration rate. Conversely, the user may want the train to reach the desired speed rapidly. A fast acceleration rate will then be entered.




The train will smoothly begin to move, and will eventually reach the desired speed. Once there, the speed control circuit maintains the constant speed, even as the train goes around curves and up and down hills.




The user may also desire that authentic sounds operate in conjunction with the desired speed. Thus, the user can enter a command that will correlate the engine “chuff” sound with the speed of wheel rotation. Another feature that may be correlated to the speed is the smoke output. If the train is moving slowly, the smoke output can be set to lightly puff or stream smoke (or steam) from the smokestack. If the user enters a new speed, for example, one that is faster than the previous speed, the sounds and smoke will automatically increase with the increase in speed. In other words, the engine “chuff” sound will become more rapid as the wheel rotation rate increases, and the amount of smoke or steam will increase, thereby simulating a harder working engine.




In addition to the engine sounds, the user may desire that other sounds be played simultaneously with the engine sounds. These may be sounds that are played randomly by the engine (with a command such as “random operating sounds”), or manually by the user entering each appropriate sound command, or by playing a customized sound sequence pre-recorded by the user. There are numerous such sounds available. A non-exhaustive list includes bells, whistles, horns, coupler slack sounds, clickety-clack sounds, cab chatter, freight yard sounds, passenger station sounds, train announcements, break sounds, maintenance sounds, dispatcher sounds, and many more. The system also allows the user to independently control the volume of multiple sounds (for example, the user can turn down the engine chuff sound, turn up the cab chatter, mute the whistle, and leave the passenger station sounds constant). The system also provides the user with a master volume control that allows the user to turn up, down, or mute all the active sounds at once.




The next feature the user wishes to activate is the Doppler sound effect. This is a one-button command on the remote control. The train sound system then activates the Doppler sound effect and the user hears a simulation of the growing and fading sounds of a train as it approaches and passes by. The realism of the Doppler sound effect can be heightened by programming it to occur at regular intervals. By so doing, the user can “time” the Doppler sound effect to coincide with each pass of the train by where the user is standing, for example.




The user now wishes to connect the model train to a consist. The user slows the train down by entering a new speed command. All sounds and smoke appropriately coincide with the change in speed. The user then hits the “coupler” button on the remote control and the coupler opens on the train (a sound file plays a coupler firing sound at the same time). The user can then bring the train into contact with the consist, the coupler on the consist is joined with the coupler on the train, and the train coupler closes upon joinder. The user can then, if desired, stop the train and reverse direction (both one-button controls). The user can enter another speed, and the train will pull away with the consist in tow.




The train, however, now has to work harder to pull the consist. This is reflected in the amount of smoke or steam is output, and in the engine sounds. The model train engine board monitors the amount of work the engine is expending in order to maintain the desired speed. As the amount of work increases, the model train will activate a new engine sound file that sounds “deeper” and more labored than when the train is moving without a load. The model train will also cause the smoke unit to produce a greater amount of smoke or steam, commensurate with the increased work load.




The user may now decide to activate some of the accessories. For example, the user may desire to turn on the lights at all the intersections. The user enters the command previously programmed by the user on the remote control (for example, “activate intersection lights.” This command is passed from the remote control to the TIU to the AIU, which activates the appropriate relay corresponding to the intersection lights. The lights at all the intersections then turn on. Other accessories are controlled in a similar fashion, including layout switches, signal lights, crossing gates, and much more.




The user may now want to become the dispatcher for the train. The user presses the microphone button on the remote control. Certain sounds, such as the bell and whistle, are muted, while other sounds, such as chuffing, will remain in order to maintain a realistic operation. The user speaks into the microphone on the remote control, and the user's voice plays out the speaker on the model train, while the train moves around the track.




Next, the user desires to play a CD. The user enters the “proto-cast” command, which tells the system that sounds from an external source will now be input. The system mutes all other sounds and waits for input from the external source (such as a CD player or computer). The sounds are played from the external source and are streamed, in real time, down the tracks where they are picked up by the model train and played out the train speaker. The user can adjust the volume using the master volume control.




When the user is ready to end his or her session, the user enters a “stop” command. The train smoothly decelerates to zero miles per hour and comes to a stop. The user then enters an “engine off” command. The train responds with a series of extended “shutdown” sound effects. Engine lights can be automatically turned off or turned off manually by the user. Finally, the user asks the train for the total “scale miles” traversed by the engine. That information is passed from the train to the remote control and displayed on the display unit. The model train processor records and maintains the total amount of mileage for each session and the total for that particular engine. Thus, the user has an accurate account of the total “mileage” and run time in hours on that particular train, which is useful for managing the maintenance of the train.




The present invention has been described with reference to its preferred embodiments. It is noted that the present invention may be embodied in other forms without departing from the spirit or essential characteristics thereof. For example, the novel control system of the present invention, for exemplary purposes only, has been described in terms of model trains. However, it should be appreciated that the novel control system of the present invention has applicability to a wide range of model vehicles other than model trains, including, but not limited to, cars, buses, metro rails, airplanes (e.g., on the runway, or while flying using RF signals directly between the engine board of the plane and the hand-held remote), bicycles, etc. In short, any type of model vehicle that moves and can be independently controlled by a user can utilize the novel control system of the present invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.



Claims
  • 1. A model train system comprising:a remote control unit that outputs commands; a track interface unit that receives the commands; and a train track layout coupled to the track interface unit; wherein the track interface unit converts the commands into a modulated signal, injects the modulated signal into a power signal so as to form an integrally formed command/power signal, and outputs the integrally formed command/power signal to the train track layout.
  • 2. The model train system of claim 1, wherein the modulated signal has a wide bandwidth.
  • 3. A model train system comprising:a remote control unit that outputs commands; a track interface unit that receives the commands; and a train track layout coupled to the track interface unit; wherein the track interface unit converts the commands into a modulated signal and outputs the modulated signal to the train track layout, wherein the modulated signal is a spread spectrum signal.
  • 4. A model train control system for controlling model trains on a train track layout, comprising:a track interface unit coupled to said train track layout; a remote control unit for communicating with the track interface unit; and a model train comprising: a processor; a speed control circuit; a sound system circuit; and a smoke unit; wherein a speed command entered on the remote control unit is communicated to the track interface unit, which passes the command to the model train via rails on the train track layout, the processor in the model train receiving the command and in turn commanding the speed control circuit to drive the model train to a speed indicated in the speed command, the processor further (1) controlling the sound system circuit to play sounds corresponding to the model train speed, and (2) controlling the smoke unit to produce smoke corresponding to the model train speed.
  • 5. The model train control system of claim 4, wherein as the speed of the model train increases, the sound system circuit plays train operation sounds which simulate a train moving at an increased speed, and the smoke unit produces an increased amount of smoke.
  • 6. A model train system comprising:a remote control unit for outputting commands; a track interface unit that receives the commands; and a train track layout coupled to said track interface unit; whereby (1) the track interface unit processes said commands and outputs the commands to the train track layout, said track interface unit being configured to receive and process data corresponding to at least one of operating and diagnostic information of a model train located on said train track layout.
  • 7. The model train system of claim 6, wherein the track interface unit provides an acknowledge signal to the remote control unit which indicates that the track interface unit successfully received and processed said command.
  • 8. The model train system of claim 6, said track interface unit being configured to communicate said at least one of operating and diagnostic information to a user.
  • 9. The model train system of claim 6 further comprising a model train operating on said train track layout, wherein said model train receives said command and outputs an acknowledge signal back to the track interface unit which indicates that the model train successfully received said command.
  • 10. The model train system of claim 9, wherein said model train processes and executes said command.
  • 11. The model train system of claims 9 or 10, wherein said track interface unit outputs a signal to said remote control unit indicating that the model train successfully received said command.
  • 12. The model train system of claim 10, wherein said track interface unit outputs a signal to said remote control unit indicating that said model train successfully executed said command.
  • 13. The model train system of claims 9 or 10, wherein operating information concerning said model train is outputted by said model train to said track interface unit.
  • 14. The model train system of claims 9 or 10, wherein diagnostic information concerning said model train is outputted by said model train to said track interface unit.
  • 15. The model train system of claim 13, wherein said operating information (1) is received and processed by said track interface unit, and (2) said track interface unit outputs a signal containing said operating information to said remote control unit.
  • 16. The model train system of claim 14, wherein said diagnostic information (1) is received and processed by said track interface unit, and (2) said track interface unit outputs a signal containing said diagnostic information to said remote control unit.
  • 17. The model train system of claim 6 further comprising an accessory interface unit coupled to said track interface unit, whereby operating information concerning one or more accessories coupled to said accessory interface unit is outputted by said accessory interface unit to said track interface unit.
  • 18. The model train system of claim 17, whereby said track interface unit outputs a command in response to said operating information.
  • 19. The model train system of claim 17, whereby said operating information is received by said track interface unit and the track interface unit outputs a signal containing said operating information to said remote control unit.
  • 20. The model train system of claim 7, whereby said acknowledge signal is displayed on said remote control unit.
  • 21. The model train system of claim 11, whereby said signal indicating that the model train successfully received said command is displayed on said remote control unit.
  • 22. The model train system of claim 12, whereby said signal indicating that said model train successfully executed said command is displayed on said remote control unit.
  • 23. The model train system of claim 15, whereby said signal containing said operating information is displayed on said remote control unit.
  • 24. The model train system of claim 16, whereby said signal containing said diagnostic information is displayed on said remote control unit.
  • 25. The model train system of claim 19, whereby said signal containing said operating information is displayed on said remote control unit.
  • 26. A model train system comprising:a train track layout; a track interface unit coupled to said train track layout; and a model train operating on said train track layout, the model train including a circuit configured to provide at least one of diagnostic and operating information to said track interface unit through said train track layout.
  • 27. The model train system of claim 26, further comprising an information appliance coupled to said track interface unit, wherein said track interface unit provides said at least one of diagnostic and operating information to said information appliance.
  • 28. The model train system of claim 27, wherein said information appliance is configured to upload said at least one of said diagnostic and operating information to an Internet.
  • 29. The model train system of claims 27 or 28, wherein said information appliance is a computer.
  • 30. The model train system of claim 27, wherein said information appliance is configured to download information from an Internet and said downloaded information is provided to said model train through said track interface unit and said train track layout.
  • 31. The model train system of claim 30, wherein said information appliance is a computer.
  • 32. A model train system comprising:a remote control unit; a track interface unit that receives commands from said remote control unit; a train track layout coupled to said track interface unit; and a model train operating on said train track layout, the model train capable of performing the commands from the remote control unit; whereby the track interface unit saves a series of commands entered on the remote control unit such that the series of commands may be repeated at a later time.
  • 33. The model train system of claim 32, wherein the series of commands saved by the track interface unit is recalled by a recall command from the remote control unit.
  • 34. A model train system comprising:a data unit for outputting data; and a track interface unit for receiving the data, wherein the track interface unit is configured to convert the data into a modulated signal, inject the modulated signal into a power signal so as to form an integrally formed command/power signal, and output the integrally formed command/power signal to a train track layout.
  • 35. The model train system of claim 34, wherein said data unit is an external sound source for providing sounds, said track interface unit being coupled to said external sound source for receiving said sounds and is configured to convert the sounds into said modulated signal.
  • 36. The model train system of claim 35, further comprising a train track layout and a model train on the train track layout capable of receiving the integrally formed command/power signal from the train track layout and processing the integrally formed command/power signal in order to retrieve the sounds and play them through a speaker located on the model train.
  • 37. The model train system of claim 35 or 36, wherein the external sound source is any one of a CD player, cassette tape player, MP3 player, DVD player, mini-disc player, or memory stick.
  • 38. The model train system of claim 35 or 36, wherein the external sound source is a computer.
  • 39. The model train system of claim 38, wherein the sounds are downloaded from an Internet.
  • 40. The model train system of claim 35, wherein the modulated signal has a wide bandwidth.
  • 41. The model train system of claim 34, 35 or 36, wherein the modulated signal is a spread spectrum signal.
  • 42. The model train system of claim 35 or 36, wherein the external sound source is a microphone.
  • 43. The model train system of claim 35 or 36, wherein the modulated signal is an FM signal.
  • 44. The model train system of claim 43, wherein the external sound source is any one of a CD player, cassette tape player, MP3 player, DVD player, mini-disc player, or memory stick.
  • 45. The model train system of claim 43, wherein the external sound source is a computer.
  • 46. The model train system of claim 45, wherein the sounds are downloaded from an Internet.
  • 47. The model train system of claim 34, wherein said data unit includes a remote control, said model train system further comprising an accessory interface unit coupled to the track interface unit and to one or more accessories located on or around a train track layout, wherein the remote control includes a memory for storing the identity of one or more of said accessories such that a command entered on the remote control controls said one or more accessories.
  • 48. The model train system of claim 47, wherein the command is received by the track interface unit, which communicates said command to the accessory interface unit for controlling said one or more accessories.
  • 49. The model train system of claim 34, wherein said data includes a Doppler effect command, said model train system further comprising a train track layout coupled to said track interface unit and a model train on said train track layout capable of playing train sounds, said track interface unit being configured to receive said Doppler effect command and convert it to the modulated signal which is outputted to said train track layout, said model train picking up said modulated signal from said train track layout and retrieving the Doppler effect command from said modulated signal, such that the model train plays one or more train sounds that simulate the Doppler effect.
  • 50. The model train system of claim 49, wherein the Doppler effect simulation is based on a fixed distance traveled by the model train around said train track layout.
  • 51. The model train sound system of claim 50, wherein said fixed distance is set by entering (1) a start Doppler loop command and (2) a stop Doppler loop command on said remote control unit, whereby the distance traveled by the model train on the train track layout during the interval between said start Doppler loop command and said stop Doppler loop command is the fixed distance.
  • 52. The model train system of claim 36, wherein the model train includes a memory for storing the sounds.
  • 53. The model train system of claim 35, wherein said track interface unit includes a memory for storing the sounds.
  • 54. The model train system of claim 34, wherein said data unit is an external sound source for providing sounds and said data includes an analog signal, said track interface unit being coupled to said external sound source for receiving said analog signal and is configured to convert the analog signal into a digital signal so as to form at least part of the modulated signalsaid model train system further comprising a train track layout and a model train on the train track layout capable of receiving the integrally formed command/power signal from the train track layout and processing the integrally formed command/power signal in order to retrieve the sounds and play them through a speaker located on the model train, said model train being configured to convert the digital signal back to an analog signal.
  • 55. The model train system of claim 34, wherein said external sound source includes an audio output, said audio output being one of line level audio and headphone.
  • 56. The model train system of claim 49, wherein the Doppler effect simulation is based on the speed at which the model train moves around the train track layout.
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