Railway track-to-locomotive signalling system - passes control data in serial form via alternating phase track loop

摘要

The railway signalling system comprises a twin-conductor phase-reversal transmission line running the length of a supervised line prior to a stop signal (2). The reversed-phased loops (100, 101) define equally-spaced track sections in which stopping distance, speed and other data can be passed to a locomotive. The control-centre transmitting equipment comprises a command unit (3) providing signals related to the required locomotive approach speed and braking with respect to the individual track sections and whether the signal (2) is in the 'stop' or all clear condition. The command signals and track section indentification (AN9 are encoded (5) and passed through a parallel-serial converter (8). A pulse generator (4) synchronises the data processing and transmitter units. The transmitter (9) is connected to the track loop.