This power supply was obtained from an Electronic Design from the 90's. The circuit applies to other 3-terminal regulators. The maximum output current is 200 mA.
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...