SINGLE_PLATE_TOUCH_SENSOR

Published:2009/6/18 4:34:00 Author:May | From:SeekIC

This system operates on the principle that capacitance loading of an oscillator will lower its fre-quency. When a foreign body comes into contact with touch plate, the frequency of U1 is lowered.This removes the oscillator signal from U1 from U2's passband, which causes U2 to lose lock, turns off the LED, and causes the colle,ctor of Q1 to go low.



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