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.
For experiments with ionization chambers and Geiger valves this circuit generates high voltage from...
This control allows to start or stop a motor up to 3 or 4 A with a low intensity signal. The...
The battery is charged by the photocell that keeps the low consumption beacon in the dark. The...