Found in a 73 magazine for radio amateurs of the 1980s, this circuit uses a dual-gate MOSFET. This component is not currently common.
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...