COMMUNICATION LINE RELAY SYSTEM

摘要

Disclosed is an improved communication line relay system for operating directly from line power including; an input-polarizing bridge circuit, a voltage-regulating circuit including a transistor and zener diode configured to bleed excess line current and to provide a regulated voltage. The system further includes a regenerative bistable circuit having a trigger input connected with the communication line for sensing the state of the received communication signal and a pair of regeneratively coupled transistors connected with the energizing coils of an output bipolar relay to apply the regulated power to the relay and to provide output states of the relay in accordance with the states of the received communication signal.