Feed imbalance detector in repeated line

摘要

A feed imbalance detector in a repeated line for detecting a feed imbalance in a PCM repeated line and for displaying an alarm includes: a constant current feeder for transmitting an operating voltage to the repeated line; a virtual ground unit for detecting the voltage difference between a plus output port and a minus output port of the constant current feeder; a comparator for comparing the voltage difference with a ground voltage, a detector for determining feed imbalance based on the output level value of the comparator after a predetermined detection time and for outputting a driving signal if feed imbalance is detected, and a display for displaying an alarm upon receiving the driving signal.