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.
Mouser Electronics is announcing the availability of the new voltage regulators with low dropout...
This circuit is from a 1982 publication but can be assembled with BF245 for Q1 and BC548 for Q2....
This circuit was found in documentation from the 1970s. It eliminates contact bouncing, providing...