This biestable touch circuit was found in American 1980s documentation. The circuit must not be powered by a source without a transformer. Sensitivity depends on the 10 M resistors.
This circuit is from 1997 documentation, based on the well-known integrated circuit 555 and 4017....
This circuit is from 1980 documentation. We can exchange the BC177 for a BC557 and the TIP41 must...
From different input voltages V, it is possible to reduce the voltage to several fixed values...