Feed line connecting circuit and optical transmission system

摘要

The circuit has a relay to detect a current above a preset value and a switch to connect one of the feed line connecting terminals to a central node in an unpowered condition. A selective switch (62a) connects between two selective contacts based on the result from the relay. Another relay (50b) between one of the contacts and the node controls the former switch to disconnect one of the terminals upon an output from relay.