Fire alarm system using the fire detector, the fire receiver, and their

摘要

PROBLEM TO BE SOLVED: To provide a fire sensor, a fire receiver, and a fire alarm system using them which require no higher power consumption than necessary in spite that they can reduce an error in detecting a transmission signal.;SOLUTION: This fire sensor is provided with a fire information detecting part 2 collecting information on fire and outputting a detection signal, a control part 3 forming and outputting detection data based on the detection signal, an oscillating circuit 4 outputting a reference signal, and a transmission processing part 5 converting the detection data to the transmission signal based on a transmission format of a transmission line to be connected by synchronizing it with the reference signal and transmitting it. The transmission processing part 5 is provided with a PLL circuit 53 multiplying an input signal and converts the transmission signal using a reference clock signal and transmits it. A multiplying level of the PLL circuit 53 is changed by the control part 3.;COPYRIGHT: (C)2003,JPO