Found in RCA documentation from the 1960s, this 60 V regulator has a 100 V input and a current of 1 A. The transistors are from that time. One can try to use modern equivalents.
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...