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.
This circuit from an old American publication uses a 12 V transformer and an incandescent lamp in an...
The integrated circuit used in this regulator is quite old. Its 1970s casing is still made of...
This crystal oscillator uses a common transistor and its frequency depends on the crystal used. We...