Receiver interface between telephone lines and switching system - has counting and coding circuits with amplifiers controlling switching relays of exchange via bistable switches (BR 20.2.80)

摘要

The receiver interface between telephone lines and electro-mechanical switching equipment comprises a first amplifier monitoring the connection between the lines. It also has a second amplifier monitoring the earth of one line and controlling switching relays of an exchange accordingly, through bistable switches. The receiver interface includes counting and coding circuits and will replace receiver and coding circuits of a telephone system without serious disturbance of the system to increase the system capacity.