Abstract: The time reset safety timer circuit eliminates approximately half of the external interfaces of the prior art safety timers. The prior art safety timers depend on vehicle axle speeds, brake indications, and/or trainline signals to initiate a safety timer reset. The time reset safety timer circuit in the present invention uses only internal information to initiate a safety timer reset. This simplifies the circuitry of the time reset safety timer circuit, which improves the reliability.

Abstract: A signal processing unit for a controller of a trolley pole switch is disclosed. The trolley pole switch switches the path of travel that an energy collector takes through the switch at a junction of catenaries at which a turn catenary and a straight catenary diverge from the straight catenary. The signal processing unit includes an input stage, a detection stage, turn and straight signal demodulation stages and an output stage. The input stage conditions modulated signals, each of which indicating a request to switch the path of travel through the trolley pole switch to the desired catenary diverging therefrom. The detection stage generates a validation signal if the conditioned modulated signal falls within a predetermined band. If the turn demodulation stage receives a conditioned modulated turn signal from the input stage and the validation signal from the detection stage simultaneously, it generates a low logic signal.

Abstract: A system detects cut-out of brakes on a train in a safe manner. Each vehicle in the train has at least one truck. Each truck has brakes which may be cut-out via a cut-out cock. A frequency generator generates a signal at a predesignated frequency. This signal is conveyed from a first vehicle in the train to a last vehicle in the train along a feed line and from the last vehicle to the first vehicle along a return line. Each cut-out cock assumes an open position wherein the brakes of its truck are cut-in or a closed position wherein the brakes of its truck are cut-out. Each cut-out cock features a switch in series with the return line that closes when its cutout cock assumes the open position or opens when its cutout cock assumes the closed position. A frequency divider for each switch connects in parallel therewith. When the switch is closed, the signal passes through the switch wherein division of frequency is avoided.

Abstract: A pulse width modulated drive circuit drives a solenoid operated valve in response to an input voltage signal from a control apparatus. The solenoid operated valve includes a coil that is energizable in response to energy received from the pulse width modulated drive circuit. The pulse width modulated drive circuit includes a pulse generator stage and an output stage. The pulse generator stage receives the input voltage signal from the control apparatus and a feedback signal from the coil which ultimately combine to form a control voltage in response to which the pulse generator stage generates a pulse width modulated signal whose duty cycle depends on the control voltage. The output stage receives the pulse width modulated signal from the pulse generator stage and generates in response thereto a pulse width modulated output signal across the coil. The pulse width modulated output signal has pulse width generally proportional to the control voltage and carries energy from a source of energy.

Abstract: An electronic controller for controlling a trolley pole switch is disclosed. The trolley pole switch switches the path of travel that an energy collector of a trolley pole takes through the trolley pole switch at a junction of power conduits diverging from the trolley pole switch. The electronic trolley pole switch controller includes a signal processing device and a power controlling device employed in tandem to control the frog solenoids of a trolley pole switch. The signal processing device detects and processes a plurality of modulated signals. Each modulated signal represents a request to switch the path of travel that the energy collector takes through the trolley pole switch to a desired one of the power conduits diverging therefrom.

Abstract: A power controlling unit for use with a radio board of a trolley pole switch controller is disclosed. The trolley pole switch has at least one frog for switching the path of travel that an energy collector takes through a junction of catenaries. The power controlling unit includes three reduction stages, a chopper control stage, and two output stages. A first reduction stage reduces power received from one catenary to an initial power level. The chopper control stage outputs two pairs of alternating signals. Controlled by a first pair of alternating signals, a second reduction stage reduces the initial power level to a secondary power level to operate the radio board. As long as it receives the initial power level, the third reduction stage reduces the secondary power level to a primary power level to operate the power controlling unit.

Abstract: A system for controlling the operation of a door comprising a first microprocessor and a second microprocessor each having a plurality of inputs for sensing the status of a vehicle. The plurality of inputs include a no motion trainline input, an open trainline input, an unlock trainline input and a close trainline input. The first microprocessor also has a close grant input for receiving a close grant signal from the second microprocessor while the second microprocessor also has a close request input for receiving a close request signal from the first microprocessor. The system also includes a motor for opening and closing the door and a motor relay circuit device, controlled by the microprocessors, for controlling the direction of power flow through the motor. When the motor relay circuit device activates, the motor is enabled to open the door and when it deactivates the motor is enabled to close the door. The system further includes a motor chopper control for controlling the delivery of power to the motor.