Faulty repeater amplifier location system for PCM transmission network

摘要

The system has a trigger circuit (TS) within each repeater amplifier (ZVx), coupled to a relay (W) allowing a resistor (RQ) to provide a loop circuit between the incoming and outgoing lines (HL, RL) at the last repeater amplifier before the fault. The incoming line is coupled to one input (E1) of the trigger circuit, the other input (E2) coupled to a measuring resistor (RM) for the remote supply current circuit. Pref. the loop circuit resistor is connected to earth via an earthing resistor (RE) and is connected in parallel with an optocoupler input, the output of which is coupled to a telemetry device (TMx).