Patent Application
20080023593
This disclosure pertains to the field of control systems for model trains, and specifically to an improvement which provides an easy-to-use and affordable system which expands the number of “on board” features available, including, but not limited to, sounds, lights, and braking.
For many years, model railroaders have desired an affordable and easy-to-use life-like model train. Early Lionel AC model trains (driven by an AC motor) were powered by an AC power pack or power supply. The power pack fed AC power to the track and the model train picked up the power by its wheels and a center feed shoe to provide the AC power to the motor. The engine speed was controlled by the amplitude of the AC voltage on the track that was varied by the user operating the levers associated with the power pack. At a later time, Lionel introduced an innovative electrical-mechanical on-board motor control unit that allowed the hobbyist to change the engine's direction by simply interrupting the AC track power. This unit was later improved by adding a neutral state to allow the train to stand idle when the track voltage was applied. This feature allowed the engine's headlight or sound to stay on while the engine was stationary. Each time the AC power was interrupted, this motor control unit had a state sequence that moved from neutral to forward, forward to neutral, neutral to reverse, and reverse to neutral. This motor control unit is often referred to as a reverse unit or “E” unit, and consisted of a solenoid device. Later, Lionel added DC voltage to the AC track to trigger the on-board whistle. A further improvement was to use positive DC to activate the whistle and negative DC to turn on or off the train's bell.
Most early trains were powered by AC motors as a cheap, reliable DC motor was not yet available. With improvements in motor technology, small DC “can” motors were made available for use in the model train engines, having such improvements in slow speed and braking and greatly reduced “lugging” or stuttering when operating the engines at slow speed. With the addition of the DC “can” motors, the operative functions of the model trains were made to appear more realistic. Also, DC power packs were easier to manufacture for the increase power demands, with better power regulation. A DC power pack has a variable DC output controlled by a user-operated lever or the like, with a double-pole double-throw (DPDT) switch to change the polarity of the DC output. The DC model train's motor is directly connected to the pickup wheels and center shoe so the engine's speed is proportional to the DC track voltage. To change the engine's direction, the user simply flips the DPDT switch on the power pack to change the track's power polarity. Only one engine can be operated on the track insofar as the voltage is the same for the entire track, thus multiple engines on the same track cannot operate independently. Multiple blocks of track, each independently powered by individual power packs must be used to independently operate multiple engines with different directions and different speeds. This is referred to as “block switching” in the model train community, and has been a staple of multiple train operation during the “Golden Era”.
In recent years, a number of electronic control systems have been developed that attempt to solve the problems of independent train control and expand remote control capability. One approach is called digital command control, or DCC. It uses a command station attached to the model train track to send AC pulses in pulse width modulation (PWM) form onto the track where the train receives the pulses via the wheels and pickup shoe. A receiver or decoder is installed in the engine to decode the pulses and provide for the various operations that the pulses would be indicative of. The decoder includes a full wave bridge rectifier to convert the AC pulses to DC and decode the AC pulse width modulation (PWM) signals to provide the control signals that are used to determine the engine's speed and direction, as well as any additional commands, such as the various sounds and the like. The train tracks DC voltage level is kept at a constant value, with the DCC system throttling the power delivered to the engine via the decoder, the decoder also providing the needed voltage at the necessary level to operate any further accessories on the train, such as lights, sounds, etc. as desired or programmed.to provide the engine's necessary drive power, and then decodes the pulse width modulation (PWM) signals to provide the control signals that are used to determine the engine's speed and direction, as well as any additional commands, such as the various sounds and the like. Since the motor is no longer directly connected to the track, the changing polarity of the track will not change the engine's direction. The engine's speed and direction command, as well as any additional commands and control, can be encoded into the AC pwm pulse packet. By generating a stream of varying pulse widths (i.e., the AC PWM pulse), many states or signals can be encoded to control the engine and any associated model train functions. The current NMRA (National Model Railroaders Association) DCC protocol defines a 56 us (microsecond) AC pulse as a “1” and a 122 us pulse as a “0”. Thus, just as in any serial communication protocol, a combination of “1”s and “0”s can be used to form any digital command signal. The command station transmits a series of digital command packets onto the track which feeds the engine. A DCC packet contains a header, address field, data field, and error detection field. By assigning different addresses in the decoders associated with each individual model train engine, multiple engines can be controlled on a single track by addressing each engine individually, with the data field information providing the functions desired, such as setting the speed and direction, sounds, lights, braking, and the like.
DCC provides the most realistic model train operation was a great step forward for modern model railroading. However, the model train community is made up in large part by hobbyists from the “Golden Era” who still prefer to use conventional DC power packs to control their engines, avoiding the use of digital command control because they either find the digital command control system is too complicated or because they prefer to operate the model trains with vintage style power controllers that were a part of the equipment from their youth. Some digital command control systems can seem overwhelming to the traditional train hobbyist/operator, with a manual having many pages relating to various control schemes; therefore using a traditional DC power pack to control the on-board module is still the first choice of many hobbyists.
U.S. Pat. Nos. 4,914,431, 5,448,142, and 5,184,048 to Severson et al, introduce the concept of changing DC track polarity and timing the duration to generate signals in order to control an on-board unit. The on-board sound modules based on this concept use the DPDT switch on the power pack to generate a control signal. The engine's speed command is in proportion to the amplitude of the track voltage, with the engine's direction controlled by the initial track voltage polarity. A fast double change polarity is used to turn the engine's bell on or off. A single change of the polarity turns the whistle on, with another change back signal turns off the whistle. This on-board sound system can control the engine's direction, speed, and two extra remote functions, mainly whistle and bell, and is compatible with existing DC power packs.
The system disclosed by Severson et al. has the certain limitations. First, there is a significant delay in the blowing of the whistle. When the direction switch is toggled, the on-board sound unit has to wait for a period of time to make sure that it is not a double change of the DC track voltage polarity before it activates the whistle. Second, it is very hard to control the duration of the whistle. When the track polarity is changed to cease blowing the whistle, the sound unit has to wait for another period of time to make sure that it is not a double change of the track polarity. Third, the system only generates two states to control the on-board sound unit; thus there is no way to generate more than two states by the toggling of the DPDT switch. Fourth, the constant need to toggle the DPDT switch is bothersome. The user's fingers can become sore from the action of operating the switch. To make the unit more user-friendly, a push button and relay circuit has been introduced to replace the flipping of the DPDT switch; however, this adds to the cost of the unit.
U.S. Pat. Nos. 5,251,856, 5,441,223, and 5,749,547 issued to Young et al., disclose providing a digital message, which may include a command, to a model train using various techniques. The digital message(s) are typically read by a decoder mounted in the train, which then executes the decoded command. A remote control unit transmits radio frequency, infrared, or other signals to a base unit. The base unit combines a frequency shift key (FSK) signal with the power signal applied to the track to send an address and data signal to the powered block section of the track. The addressed train on that power block section will receive and decode the signal. The Young system does not send the signal directly to the on-board sound module.
To overcome the above limitations and reduce the cost, the present disclosure introduces a low cost, five function wireless transmitter and receiver chip set to generate control signals to the on-board sound module. Instead of using a DPDT switch to change the polarity of the track voltage to generate limited signals, the receiver chip sends 5-bit digital signals to the I/O port of the microcontroller of the on-board sound unit. The five-function wireless chip set can generate 5-bit binary code to input to the microcontroller on the on-board sound unit. This means that a low cost wireless solution can be used to activate up to 32 remote functions to control the on-board sound unit. That is enough to activate all the necessary on-board sounds and other functions and make model railroading more life-like.
In accordance with the present disclosure a control system has been developed for AC or DC powered model train system which uses an on-board sound module to control the model engine's sound and other on-board features. On-board means that it is integrated into a remote object (a minature model locomotive in this case) that is addressed by the remote control signals. The object is to increase the number of remote control functions to meet the ever increasing availability and desireability of “on-board” features, such as head light, tail light, Mars lights, whistle, air horn, bell, air release, brake, emergency stop, announcements, etc. This control system is compatible with traditional power packs, sending the control signals wirelessly rather than through the power on the track. Using the wireless controller, the hobbyist will also be able to walk around his layout to operate his engines unencumbered.
The control system can be implemented for DC model trains and some AC model trains driven by DC motors.
As shown in
If the MCU does not detect a DCC track signal, it will try to determine whether the track is AC powered or DC powered. If it finds the power track is AC, as shown in
If the MCU does not detect a DCC track signal or AC voltage on the powered track, it determines that the track is powered by a DC power pack 507.
A program executed on a computer and associated with the on-board sound module causes the computer to perform the steps of receiving and decoding the digital control signal to control the on-board train functions, such as various sounds and lighting functions.
A further embodiment of the DCC control for the MCU would include the use of direct wireless reception of the wireless control signals to the MCU via a UART (universal asynchronous receiving transmitter) incorporated in the MCU. The UART receives the transmitted commands directly from the wireless transmitter without having to pass the signals to the wireless function receiver, allowing the track to be powered by a standard DC or AC power pack.
The thus modified MCU would be placed in the model train engine or, if desired, various model cars, to provide the needed functionality.
The UART may be included as a separate chip in an electrical connection to the MCU and mounted on the same board, it it may be manufactured on the same silicone chip as the MCU.
The wireless transmitter would incorporate an RF module that is used to transmit the commands wirelessly directly to the UART incorporated MCU for execution in the model train.
While presently preferred embodiments have been described above, various other modifications and adaptations of the instant invention can be made by those persons skilled in the art without departing from either the spirit of the invention or the scope of the appended claims.
This application is a continuation in part of U.S. patent application Ser. No. 11/030,959, filed Jan. 10, 2005, hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11030959 | Jan 2005 | US |
| Child | 11812230 | Jun 2007 | US |
