This triac circuit was found in the July 1995 Electronics Now magazine. The triac is based on the heating element current and must be equipped with a heat sink.
One of the problems with common 3-terminal regulators is that the internal reference, normally 1.25 V,...
This windshield wiper interval was found in old documentation. The NPN transistor is general...
This circuit was found in a Radio Escuela Gráfica magazine from Argentina published in the 70's....