TRACK CIRCUIT Russian patent published in 2002 - IPC

FIELD: railway transport; railway signaling and communication; train traffic control systems. SUBSTANCE: supply source through resistor and first transformer is connected to one end of track circuit and first analog-to-digital converter is connected to other end of track circuit through second transformer, first rectifier and first filter. First and second front contacts of control relay are connected to input terminal of first transformer, resting contacts of relay are connected to output terminal of second transformer and common contacts are connected to output terminal of supply source and to one of resistor poles. Third and fourth front contacts of said control relay are connected to output terminals of second transformer, resting contacts are connected to input terminals of first transformer, and common contacts of these tee devices are connected to input terminals of first analog-to-digital converter. Second analog-to-digital converter is connected to resistor poles through second filter and second rectifier. Output terminals of both analog-to-digital converters are connected to input terminals of permanent memory. Front contact of track relay is connected between plus pole of supply source and fifth common contact of control relay. EFFECT: improved reliability at reduced insulation resistance. 2 dwg