FIRE DETECTOR EMPLOYING PYROELECTRIC INFRARED RAY DETECTOR

摘要

PURPOSE:To detect fire quickly with a high sensitivity by means of the pyroelectric infrared ray detector, the chopper and the means adapted to trigger the chopper by generating the output voltage of the detector exceeding the fixed level. CONSTITUTION:The chopper 2 is provided before the light receiving point of the pyroelectric infrared ray detector 1. When the amplification circuit 4 outputs the output voltage exceeding the set threshold, the chopper drive control circuit 3 comprising an electronic switch or an relay and the like works triggering the chopper 2 to start the driving. The chopper drive control circuit 3 has a means of halting the driving.