Light control switch using photoresistor

Published:2011/11/10 1:52:00 Author:May | Keyword: Light control switch, photoresistor | From:SeekIC

It utilizes power MOS FET as power switch, and the witch sensing element can adopt photoresistor LDR. Whenlight shines on photoresistor, LDR presenst low resistance,andwhen there issignal addingto thegrid of FET, the source-drain is conducted tomake relay coil K change state andgenerate controlling usage or signal. Ifthe photoresistor LDR is connected to low-level position, when it is dark and has no light shining on photoresistor, then the value of photoresistor is high, so VMOS's grid level is high to make lamp L be bright. Reversely, whenthere islight shining on LDR, VMOS grid is inlow level and closed, lamp L isnot bright.



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