This source with two symmetrical output voltages was found in 90s Radio Electronics. The 22 V output has a maximum current of 300 mA and the 5 V output has a maximum current of 4 A.
The circuit shown is from an old European publication. In it we have the way to activate a relay...
We found this circuit in a European publication from the 1990s. Transistors are still common types...
This circuit was found in an American documentation and can be added to common amplifiers of any...