Line disconnecting circuit of fire alarm

摘要

(57) [summary] in line disconnecting circuit for disconnecting a short-circuited portion at the line short-circuit of a pair of lines of [purpose] for the fire detector is connected to the power supply and signal of the fire alarm, the disconnect circuit that worked from the fire receiver It was to be identified. [Configuration] and the line voltage detection circuit for detecting a voltage of a short circuit of the pair of lines, a switching circuit for disconnecting the line on the basis of a short circuit detection signal from the line voltage detecting circuit, the short circuit detection signal from the line voltage detecting circuit Specific to be sent to the fire receiver a specific signal when the short circuit detection signal from the transmission circuit or a line voltage detector circuit, and to the operation information detach based returns in response to the address call from the fire receiver is output and a signal generation circuit, a fire alarm, characterized in that it has to identify the disconnecting circuit that operates at the fire receiver side line disconnection circuit.