We found this circuit in the September 1994 issue of Electronics Now magazine. The circuit uses off-the-shelf components and is powered by mains power.
This circuit is from an English magazine of 1977. The circuit is still current, just using BC547...
The adjustment of the maximum load voltage is made in the trimpot. The circuit is from 1994...
In the figure we have the conventional configuration of a differential amplifier with the...