This circuit works like a solid-state contactor. We find it in General Electric documentation from 1965. SCRs can be modern equivalents according to the controlled load.
We found this circuit in a 1986 documentation. It causes 40 LEDs to flash sequentially. The big...
Exciting a sequential circuit with the output of a stereo we can make a set of lamps run at a...
This alarm from an old 1978 publication uses PNP transistors and driver and output transformers that are...