Used with infrared remotes at the time, this circuit was found in a 1991 RE Experimenter Handbook. It may not work with the faster remotes control used today.
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...