This circuit was found in documentation two years 80. Transistors can be modern equivalents. Or circuit can be modified to operate with lower voltage.
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...