BATTERY FEED CIRCUIT FOR A PAIR OF SUBSCRIBER LINES

摘要

A voltage drive circuit is provided for each subscriber line. The circuits each independently include an operational amplifier having a predetermined output impedance determined by an attenuating current terminal impedance for the pair of lines. Voice signals and induced noise signals are terminated by the voltage drive circuit. The amplifier is a voltage follower for direct current, and operates as an inverting amplifier for alternating current. The circuit is terminated by an impedance for voice signals and by an impedance for induced longitudinal noise signals.