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.
In figures 1 and 2 we have two current drains that can be made with operational amplifiers and...
Great sensitivity for the circuit can be obtained with a Darlington amplification step for the...
The used diode is an unusual component today. We found this 12 V regulator in documentation from the...