LM324 manufactured using low-cost PIR switch circuit diagram

Published:2014/2/26 20:43:00 Author:lynne | Keyword: LM324 manufactured using low-cost PIR switch circuit diagram, | From:SeekIC

LM324 manufactured using low-cost PIR switch circuit diagram shown in Fig.: Human pyroelectric infrared detection portion , mainly by the Fresnel lens and pyroelectric infrared sensors, four operational amplifier (LM324) and other components. When the range of the human body into the sensor monitoring , infrared energy lens focused into the low- pass amplifier noninverting IClA , C1, C2, C4 is a high frequency filter capacitor , C3 , and C5 infrared channel low-frequency AC signal . ICIB for the inverting amplifier by R5, R6 and the partial pressure of the noninverting terminal of the bias IClB 1 / 2 Supply voltage to amplify the AC signal , C7 is a high frequency filter capacitor, the two amplifier R3, R2, R8 , R4 determine the amplification gain . IClC composition comparator , ⑩ feet, through R10, R11 divider setting a reference voltage of about 3.9V , the reference voltage is also at the same time as the delay circuit IClD monostable trigger threshold level , 1CIC the comparison voltage signal ⑨ pin , in the photosensitive resistor RG acquired by IClB output through R9 , daytime RG by light , resistance ≤ 10kΩ, IClB high signal output by R9, RG partial pressure is still lower than IClC noninverting terminal level , IClC high power output flat , D1 reverse bias cut . IClD monostable circuit without trigger signal output high , SCR are off, the lamp is not lit . RG no light at night , its resistance ≥ 1MΩ, so IClC output low , D1 is turned on C9 discharges , IClD output low, the lamp is powered light. In the human left , ⑧ feet and high recovery , D1 and off, the power of C9 recharged by W1 , by the delay , when the voltage is higher than C9 ⑥ foot 3.9V, and a single flip -flop circuit IClD output high , lights off. Triac drive circuit triggered by BG SCR, can trigger more reliable.



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