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 circuit was found in the SGS manual of linear integrated circuits of 1982. The circuit...
We found this circuit in the National Semiconductor Linear Applications Handbook of 1994. The...
This simple strobe light is from an article in 1982. Its complete circuit, very simple, appears in the...