PHOTOELECTRIC SEPARATION TYPE SENSOR

摘要

PROBLEM TO BE SOLVED: To simplify the constitution and to lower the cost without increasing the line length of an electric conductor by providing a photodetection part with a cycle selection switch for selecting transmission cycles of a synchronizing signal and outputting the synchronizing signal on the cycles selected with the cycle section switch. SOLUTION: A photodetection part control circuit 3 once judging a fire from the quantity of light photodetected by a photodetecting element 12 in synchronism with synchronizing pulses and inputted through a photodetecting amplifier circuit 14 and a sample holding circuit 15 turns on a fire signal output switching element 4 to turn on a fire pilot lamp 5 and also inform of the fire a receiver connected to terminals T1 and T2 through fire signal lines. In this case, the photodetection part outputs the synchronizing signal to a synchronous line on specific cycles and also receives the synchronizing signal from the synchronous line to emit light. The photodetection part has the cycle selection switch 18 for selecting transmission cycles of the synchronizing signal and outputs the synchronizing signal on the cycles selected by the cycle selection switch 18.