This circuit was found in documentation from Analog Devices from the 90s. The circuit uses components from that time, which are not common today. It serves as a reference.
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...