| 摘要 |
PROBLEM TO BE SOLVED: To prevent the defective performance of a receiver due to the failure of a line connecting a detector/an outside device and the receiver and to also stop a failure alarm under construction by operating a switch when the detector is not connected to the receiver through the detection line. SOLUTION: This device is provided with the detector G outputting a two stage applied voltage being an applied-voltage in monitoring mode and an applied-voltage in a detection mode, the receiver R to which the detector is connected through the detection line L and which has a receiver control circuit CPU, and the outside devices connected to the receiver, and the receiver is provided with two stage applied-voltage level detection circuits Q1 and Q2, a line failure signal circuit Q6 for no voltage detection, an output circuit Q3 in a detection mode which transmits a signal to a receiver control circuit in the case of detecting an applied-voltage in a detection mode and transmits an applied-voltage in a pseudo detection mode to the outside device, output circuits Q4 and ZD2 in a monitoring mode which turn off the line failure signal circuit in the case of detecting the applied-voltage in a monitoring mode and transmit the applied-voltage in a pseudo monitoring mode to the outside device, and a failure alarm stop circuit Q5 turning off the line failure signal circuit by the operation of the switch when the detector is not connected to the receiver.
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