COMMUNICATION LINE INTERRUPTION ALARM DEVICE

摘要

PURPOSE:To provide the device warning it immediately when a telephone line is broken. CONSTITUTION:A line voltage detection section 1 sensing an applied voltage is connected to the communication line, an operating current detection section 6 sensing a current flowing to the communication line when a telephone set is in use is inserted in the communication line, a logic circuit section 11 is connected to an output of the line voltage detection section 1 and the operating current detection section 6 so as to output an alarm signal from the logic circuit section 11 when no detection output is obtained from both the detection sections 1, 6 and an alarm section 13 is operated by the alarm signal outputted from the logic circuit section 11.