Infrared burglar alarm circuit
Posted on Mar 28, 2007 10594
Infrared reflective burglar alarm, infrared detection using reflective components (maximum detection range of up to 12m) to trigger the alarm, when Pirates of the situation is detected, an alarm will sound realistic barking to alert the owner of
"outsiders people invasion. " (1) infrared reflective circuit burglar alarm circuit from the power circuit, infrared probe guillotine circuit, speech generator and audio amplifier output circuit, as shown in FIG. Power circuit from the power transformer T, rectifier bridge pile, filter capacitor C4, G and three-terminal regulator set circuit composed of 7812. Infrared detection circuit by the infrared reflection-type probe guillotine module IC1, resistor Ri, Zener diode VSI components. Sound by the sound generator integrated circuit IC2, resistor Rz, wind and Zener diode VS2 composition. Audio amplifier output circuit consists of audio power amplifier integrated circuit IC3, capacitor c] ~ G, G and speakers: B components. (2) circuit works AC 220V voltage by T Buck, bridge rectifier, C6 filtered all the way to IC3 provide 15v DC pulsating voltage; another path roar regulator, IC1 to provide ten 12V operating voltage, + 12V voltage also after the monument island limiting pressure and VS2 regulator, to provide LC2 + 3V operating voltage. In normal circumstances, IC1 output low. IC2 can trigger work, speakers BI. No sound. When a stranger enters IC1 vigilance probe guillotine area. Ki infrared signal emitted by the human body reflected back. IC1 receives the body reflected infrared signal and the signal to go to treatment, the trigger outputs a high level signal to the IC2 triggered by the work, the output of the audio signal. After this signal by the power amplifier IC7, drive BL loud barking, suggesting master "abnormal situation" took place.