This circuit was found in a Popular Electronics from the 90s. It is based on components still common today and an optical coupler for the triac. The sensor is a thermistor.
This circuit was found in the 1972 RCA Power Transistor Databook. Transistors are uncommon today,...
This circuit is used to light a 20 W fluorescent lamp from the 12 V of a car battery. The...
This circuit fires by burning the fuse when the input voltage exceeds the value referenced by the zener....