DEVICE OF PREVENTING HOOK-OFF

摘要

The apparatus is for receiving ringing signal even when a handset is not in stand-by mode by alarming the user and opening the loop of a telephone when voice signal isn't detected for a certain time or hook-signal of receiving-off is detected. It includes a ring detector (4), a microprocessor (11) for detecting fault signal sound, a hook switch controller (5) for interfacing the signals transmitted by telephone exchanges according to control signal from the microprocessor (11), a loop controller (10) for controlling the loop of telephone wire, the 1st and 2nd amplifiers (20,21), and an alarm sound regulator (22) for regulating the output of the 2nd amplifier (21) and outputting to a speaker (23).