This circuit was found in a 80’s American documentation. The adjustment trimpot is from 47k to 100k. The diodes are general-purpose types use and the supply voltage depends on the relay.
This voltage regulator was obtained in the SGS manual of linear integrated circuits of 1982. The...
Of course, the design indicates a specific application for a touch switch. Thus, analyzing the...
In the figure we have the way to obtain the Exclusive-OR function with 1 transistor. The circuit...