We found this circuit in a 1978 documentation. The SCR conducts when the regulator's output voltage exceeds the zener voltage.
This simple unijunction circuit is from a Radio Electronics from July 1963. It can be assembled with a...
Using 555 integrated circuits, this alarm circuit was found in a 90s American documentation. The signal...
This circuit with transistors was found in an old Japanese publication, translation of an American...