Not Applicable
Not Applicable
This invention relates generally to accessories for toy or model railroad layouts and more particularly to an improved combination signal and train detector for such layouts.
There is a demand for model railroad accessories that simulate signals used on full sized railroads. Such accessories include block signals, semaphores, wig-wag signals and others. A block signal controls the passage of trains by providing a red or green signal to the engineer indicating whether it is safe to pass the block signal.
In full size trains, signals such as block signals semaphores and the like (collectively referred to herein for convenience as block signals) are controlled by a variety of complex mechanisms the precise duplication of which is not practical in model train layouts. This invention may be applied to signals that control the passage of trains, and to signals that control the passage of vehicular traffic at grade crossings. Accordingly, it has become common to provide block signals in model train layouts that turn red when a train approaches and turn green after the train has passed. Previously known block signals have been relatively simple devices that include a red light and a green light that can be selectively illuminated by applying appropriate activating signals to inputs of the block signal. The inputs to the block signals have come from a variety of sources generally referred to as train detectors. Known train detectors include detectors that use a section of isolated track that is responsive to a train passing over it and light or magnetic sensors to detect the presence of a passing train.
Heretofore, providing block signals responsive to the passage of trains has required the use of multiple devices and sometimes complex wiring connections between them.
It is an object of this invention to provide a combination of a block signal and train detector that greatly simplifies installation compared with known approaches.
It is another object if this invention to provide a combination block signal and train detector that can be easily synchronized with similar devices positioned at remote locations on a model train layout.
It is another object of the invention to provide a combination block signal and train detector that uses simple inexpensive circuitry that allows the device to be manufactured and sold at reasonable prices
Briefly stated, and in accordance with one embodiment of the invention, a combination model train sensor and block signal includes a train proximity sensor, a red signal light, a green signal light, and a controller connected to the proximity sensor and the red and green signal lights. The controller turns on the green signal light and turns off the red signal light when the proximity sensor indicates the absence of a train, and turns on the red signal light and turning off the green signal light when the train proximity sensor indicates the presence of a train.
In accordance with another aspect of the invention, a combination model train sensor and signal includes a train proximity sensor, a safe to proceed signal and a stop signal connected to a controller as just described in which the controller activates the safe to proceed signal and deactivates the stop signal when the proximity sensor indicates the absence of a train and activates the stop signal and deactivates the safe to proceed signal when the train proximity sensor indicates the presence of a train.
In accordance with another aspect of the invention, the signal is a wigwag or swinging banjo signal.
In accordance with another aspect of the invention, the signal is a semaphore signal.
In accordance with another aspect of the invention, the signal is a target signal.
In accordance with another aspect of the invention, the train proximity sensor of the model train sensor and signal includes a light source, preferably an infrared light source, and a light detector, preferably an infrared light detector, arranged to reflect and detect from a passing train to indicate its presence.
In accordance with another aspect of the invention, the combination model train sensor and signal includes an output connected to the train proximity sensor for producing an output signal when the sensor indicates the presence of a train, which output can be used for controlling a remote block signal.
In accordance with another aspect of the invention, the combination model train sensor and signal includes an input, responsive to a signal received from a remote sensor, for controlling the illumination of the red and green lights and synchronizing two block signals.
In accordance with another aspect of the invention, the combination model train sensor and signal includes a combination input/output connected to the controller, the input/output producing a train present signal when the train proximity sensor indicates the presence of a train and being responsive to an externally applied train present signal for turning the red light on and the green light off even when the local train proximity sensor indicates the absence of a train.
In accordance with another aspect of the invention, the combination model train sensor and signal includes a first transistor switch for turning on the green light, the first transistor switch preferably connected to be normally on and a second transistor switch having an input connected to the train proximity sensor and an output connected to the red signal light and to an input of the first transistor switch to turn the red signal light on and apply an off signal to the input of the first transistor switch to turn the green signal off. The second transistor switch is preferably connected to be normally off.
In accordance with another aspect of the invention, the input/output is connected to the second transistor switch.
The novel aspects of the invention are set forth with particularity in the appended claims. The invention itself together with further objects and advantages thereof may be more readily understood by reference to the following detailed description of a presently preferred embodiment of the invention taken in conjunction with the accompanying drawing in which:
Referring now to
The block signal detector 10 includes a red signal light 14 and a green signal light 16 arranged in the upper portion of a housing 20 that is configured to look like an actual block signal, of the type used on a full sized railroad. To that end, a simulated access door 22 is provided in the lower portion of the signal and the signal lights 14 and 16 are arranged in a conventional top and bottom configuration. Preferably, light hoods 24 and 26 surround the lights to make the signal lights visible in bright sun. Preferably, the block signal detector is formed of relatively high impact plastic to provide a durable but low cost construction. The plastic housing can be injection molded to produce a pleasing appearance at low cost. The internal components of the housing are mounted on a printed circuit board that is actually accessed through a rear cover plate 30 rather than simulated access door 22.
Preferably, an infrared light source 32 is mounted on the printed circuit board (not visible in this figure) and extends through an opening in housing 20. A preferably infrared sensor 34 is mounted in relatively close proximity to infrared source 32 but the source and detector are arranged so that the detector is not responsive to light emitted directly from the source but is responsive only to a light reflected from a passing model train. An internal light barrier between the source and the detector may also be used.
The operation of the block signal detector will now be described in conjunction with the schematic diagram of a presently preferred embodiment of a controller therefor shown in
The block signal detector circuitry is designed to be powered from a 12-14 volt AC source sometimes referred to as a transformers of the type used to provide power to the engines and accessories of model trains. Power input terminal 50 is adapted to be connected to the AC power source and a common terminal 52 which for convenience may be referred occasionally herein as a ground terminal even though is it is not in fact grounded, is adapted to be connected to the opposite side of the power source. A rectifier diode 54 is connected between the power input terminal 50 and a light emitting diode 56 which is preferably an infrared light emitting diode. Current limiting resistors 58 set the current through infrared emitting diode 56 to a level that balances long diode life with sufficient light output to reliably detect the presence of model trains.
the arrangement just described produces a stream of light pulses having a repetition rate of approximately 60 hertz from infrared emitting diode 56, rather than a constant beam. An infrared detector 60 is connected to an inverting input 66 of an operational amplifier 68. Operational amplifier 68 is preferably ½ of an LM393M dual operation amplifier. A high pass filter, including a capacitor 62 and a resistor 64 is connected between the output of infrared detector 60 and an input 66 of an amplifier 68 to substantially eliminate false triggering caused by constant ambient light. This permits the sensitivity of operational amplifier 68 to be set relatively high for reliable train detection without increasing false triggering from ambient light. The sensitivity of the operational amplifier 68 is set by a variable resistor 70. The remaining components associated with operational amplifier 68 are conventional and will be readily understood by those skilled in the art.
An output 72 of an amplifier 68 is connected to an inverting input 74 of a second operational amplifier 76 configured as an inverter to correct the sense of the output signal for operating the controller of the block signal detector. The output terminal 80 of the amplifier 76 is connected through a resistor 82 to the base 84 of a transistor 86. Base 84 is normally held high by resistors 88 and 82 so that the transistor is normally on. Output 80 pulls base 84 essentially to ground through resistor 82 when a train is present as indicated by the presence of reflected infrared light at detector 60. The portion of the block signal detector just described is indicated in phantom lines in
Referring back to
When a train is detected, the signal applied to the base 84 of transistor 86 goes high turning transistor 86 on. The voltage at base 110 of transistor 112 is pulled low to a voltage of approximately equal to the saturation voltage of transistor 86 plus the voltage drop of light emitting diode 100, the sum of which is approximately 1.7 volt which turns transistor 112 off and extinguishes light emitting diode 114.
In accordance with a presently preferred embodiment of the invention a time delay is provided so that the red signal lamp remains illuminated and the green signal lamp remains extinguished for a pre-selected time after the proximity detector has detected the passage of a train. Time delay capacitor 126 is connected the output 72 of amplifier 68 and ground. The time constant of capacitor 126 and resistor 128 connected in series therewith, sets the predetermined time. Preferably, a time of about 2 seconds is provided.
In accordance with the preferred embodiment of the invention, an input/output terminal 20 is provided. Input/output terminal 120 is connected to collector 104 of transistor 86 through a small isolation resistor 122. It will be appreciated that when a train is detected by the proximity detector 90 and transistor 86 is turned on, the input/output terminal 120 is pulled low through resistor 122. When no train is present and transistor 86 is off, the input/output terminal 120 is high.
If a low or ground remote signal is connected to input/output terminal 120 it will be appreciated that the collector 104 of transistor 86 will be pulled low whether transistor 86 is turned on or off by proximity detector 90. Since transistor 86 is normally off in the absence of a train, it will be seen that a remote train present signal applied to input/output terminal 120 will turn red signal light 100 on and turn green signal light 114 off. This allows two block signal detectors in accordance with the invention to be synchronized so that when one detects the presence of a train, the light in the other will also turn from green to red. The synchronization is bi-directional and the wiring is exceeding simple as will be seen by reference to
Preferably, an infrared light source 218 is mounted on the printed circuit board (not shown) and extends through an opening in a housing 222. A preferably infrared sensor 220 is mounted in relatively close proximity to infrared source 218, but the source and detector are arranged so that the detector is not responsive to light emitted directly from the source but is responsive only to light reflected from a passing model train. An internal light barrier between the source and the detector may be used if desired.
A controller for the combination model train sensor and simulated block detector of
A light source 322 is mounted on support 304 and projects a light beam through light filters 312, 314 and 316, respectively, in the three positions of the semaphore signal. Preferably, light filter 316 produces a green light, light filter 314 produces a yellow light, and light filter 312 produces a red light. In this way, only a single light source 322 is required to provide three different colored simulated signals.
An elongated vertical column 404 supports one or more target signals of which two, signals 410 and 416, are shown in
Stop signal 416 includes a preferably red light 412 and a light hood 414. Safe to proceed signal 410 includes a preferably green light 406 and a light hood 408. Housings 418 and 420 contain the light sources, which may be a conventional incandescent or LED lamp. The electrical connections to which are entrained through support 404 into base 400.
As shown in
As shown in
A generalized controller for the combination model railroad sensors and signals in accordance with this invention is shown in
The light from the infrared source is reflected from a passing model railroad engine or car 510 and detected by infrared detector 506. Detector 506 is connected between the five-volt source 500 and ground 528 through a current limiting resistor 508. A low pass filter comprised of capacitor 512 and resistor 514 conditions the output of detector 506, which is applied to input 3 of controller 516. Terminal 8 of the controller is connected to ground in terminal 1 to the five-volt source. The controller has four outputs for selectively enabling thee visual output devices illustrated as a light emitting diodes 520, 522 and 524 which are preferably red, yellow, and green, respectively, all connected to the five-volt source 500 through a current limiting resistor 518. An actuator, indicated generally at 526, is connected to output 7 and to the five-volt source. The actuator 526 may be actuator 322 of the semaphore signal or the actuator for the wigwag signal shown in
While the invention has been described in connection with the presently preferred embodiment thereof, those skilled in the art will recognize that a number of modifications and changes may be made therein without departing from the true spirit and scope of the invention which accordingly is intended to be defined solely by the appended claims:
This application is a continuation of U.S. application Ser. No. 10/615,130 filed Jul. 8, 2003, which is a continuation-in-part of U.S. application Ser. No. 09/826,654 filed Apr. 5, 2001 (Now U.S. Pat. No. 6,660,429).
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Number | Date | Country | |
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20070075191 A1 | Apr 2007 | US |
Number | Date | Country | |
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Parent | 10615130 | Jul 2003 | US |
Child | 11468802 | US |
Number | Date | Country | |
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Parent | 09826654 | Apr 2001 | US |
Child | 10615130 | US |