This is one of many possible touch switch configurations using CMOS integrated circuits. The circuit is from a 1980s American documentation. The power source must be isolated.
In the original 1992 application, this passive circuit was intended for use in the car. At that...
This 1995 circuit uses an audio amplifier that is no longer common today. However, other...
This circuit is from an 80's documentation. The integrated circuit is from the time and the...