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.
This circuit is from a 1976 Motorola CMOS manual. It can be implemented with modern Darlingtons like...
The circuit presented is from a 1972 RCA technical documentation. The integrated circuit consists of a...
We found this transmitter circuit for different frequency ranges in a 1992 documentation. The...