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Signal processor circuit with Pyroelectric infrared sensor

Published on Jul 22 2010 // Pyroelectric Sensor circuits


Pyroelectric infrared sensor signal processor circuits


The OT0001IC is a Pyroelectric infrared sensor signal processor . It is a high performance sensor with signal processing integrated circuits . If IC OT0001 is hard to get in market, it can also be replaced by BISS0001(Micro Power PIR Motion Detector IC chip), which is fully compatible. It is accompanied by pyroelectric infrared sensors and a small amount of external components . With these, it forms a passive pyroelectric infrared switch . It can automatically and quickly switch ON all kinds of incandescent , fluorescent lamp, buzzer , automatic doors , fans , dryers and automatic hand-washing and other devices , especially suitable for industries, hotels , shopping malls, housewares, corridors and other sensitive Regional , or zone automatic lighting for security , lighting and alarm systems .

The operation of the circuit is that,  the operational amplifier (inbulilt in OT0001) OP1 will amplify the output signal from pyroelectric infrared sensor as the first -class amplification, and then with the help of C3 which is coupled to the second stage, makes operational amplifier OP2 to amplify. Then, through the voltage comparator COP1 and COP2 a two-way Amplitude Processing, detection is done. Then, the  effective trigger signal starts the delay timer Vs . The output signal Vo is amplified by the transistor T1 and send to relay to connect the load .

Photosensitive resistor R3 is used to detect environmental light intensity . If the environment is more bright , R3 resistor value will reduce the  input  pin 9 to remain low , thereby blocking the trigger signal Vs. Selector switch SW1 is work , when SW1 and a client connected , the chip is reusable trigger work ; when SW1 and 2 end connectivity , the chip is triggered in a non- duplication of work. Output delay time Tx from the outside to adjust the size of R9 and C7 , a value of Tx ˜ 24576xR9C7; trigger block of time Ti. R10 and C6 from the externall side is used to adjust the size , value of Ti ˜ 24xR10C6.