TRACK CIRCUIT Russian patent published in 1997 - IPC

FIELD: railway transport; traffic control. SUBSTANCE: track circuit has transmitter 3 connected with rails through its output and resistor 2 on one end of rail line 1 and connected through control input with output of control mode setting unit 4 whose input is coupled through delay element 5 with output of functional converter 6, and control input is coupled with made contact 7.1 of track relay 7 whose winding is coupled through track receiver 8 with rails on other end of rail: line 1 and with input of amplifier 9 with automatic gain control. It has also mean value detector 10, signal level converter 11 and switch 12 connected by inputs directly and through signal level converter 11 to output of amplifier 9 with automatic gain control, and by control input, through matching element 13, to transmitter output and by output, to mean value detector input whose output is connected to input of functional converter 6. EFFECT: enhanced safety. 2 dwg