This circuit uses a wire potentiometer, but the current is much more intense in the control thanks to the 2N3055 which must be mounted on a heat sink.
This circuit is from an English publication from 1978, but it can be assembled with BC548 for TR2...
This simple voltage regulator with FET was found in American documentation from the 1980s....
This circuit was used to regulate the speed of small DC motors of cassette recorders. However, if the...