Indicated for automotive use, this circuit was found in a Popular Electronics from the 90s. The circuit uses a power transistor that must be equipped with a heatsink.
This circuit is from a March 1978 Radio Electronics magazine article that showed how to build it....
This circuit was obtained from an article in Radio Electronics magazine in October 1966. It...
In the figure we have a bistable circuit that activates LEDs from touch rings and turns off data...