This is a Simple Complementary metal–oxide–semiconductor connect switch circuit diagram, CMOS technology is used in microprocessors, microcontrollers, static RAM, and other digital logic circuits. This connect switch does not rely on mains hum for switching-It-can be used with battery powered circuits.
Simple Cmos Connect Switch Circuit Diagram
Schmitt trigger IC1 forms a 100 kHz oscillator and IC2a which is biased into the linear region, amplifies the output and charges CI via the diode. IC2b acts as a level detector. When the sensor is touched, the oscillator signal is severely attenuated which causes CI to discharge and IC2b to change state.