The figure shows how to vary the output voltage of a 7812 regulator between 12 V and 2 V less than the input voltage. The circuit is from Radio Electronics from July 1984 and can be applied to series regulators with other voltages.

The figure shows how to vary the output voltage of a 7812 regulator between 12 V and 2 V less than the input voltage. The circuit is from Radio Electronics from July 1984 and can be applied to series regulators with other voltages.