This regulator can be controlled by a logic signal. The circuit is from an Electronics Now from the 90s. Note that the switching transistor is before the integrated circuit.
This simple trigger circuit was found in a 90’s American documentation. The integrated circuit is...
This sensitive circuit was found in the August 1971 issue of Radio Electronics magazine. The SCR...
The varactor or varicap diode tunes the signal for listening to SSB signals on a common receiver. The...