TRACK CIRCUIT Russian patent published in 2009 - IPC B61L23/16 

FIELD: transport.

SUBSTANCE: track circuit comprises track, track generator (1), first bandpass filter (3), rectifier (8), ADC, comparator (13), track relay with terminal, counter (17), synch generator (29) and temperature transducer (31). Additionally, track circuit comprises the 2^nd bandpass filter (7), 1^st and 2^nd track transformers voltage divider consisting of 1^st and 2^nd resistors, 3^rd resistor (21), another ADC (12), amplifier (14), 1^st and 2^nd set of logical elements OR, 1^st and 2^nd set of logical element AND, rainfall amount pickup (30), current relay and its repeater. With the train approaching aforesaid track circuit, reference voltage, i.e. receiver input voltage, is recorded, multiplied by voltage drop factor to produce threshold voltage. Is threshold voltage exceeds current voltage, track line is considered occupied if current voltage exceeds threshold voltage track line is considered unoccupied. Voltage drop factor is taken to be dependent upon current voltage, that is, upon state of ballast. Threshold voltage is corrected allowing for three following factors, i.e. state of ballast resistance, ambient temperature and amount of rainfall.

EFFECT: higher safety of railway traffic.

1 dwg