This circuit was found in a 1970s American documentation. It can be applied to almost any regulator. The transistor used admits equivalent, depending on the circuit current.
This series and parallel sensor circuit was found in Popular Electronics from the 1990s. Any SCR...
This circuit was found in a 1973 documentation, being able to use any general purpose NPN...
This circuit was found in a 1974 documentation. The bipolar transistor can be the BC548 and at the...