This circuit with two transistors was found in ancient European documentation. Transistors support equivalents. The indicator on this circuit is an ordinary 50 to 100 mA lamp.
One of the problems with common 3-terminal regulators is that the internal reference, normally 1.25 V,...
This circuit found in French documentation, works with 15 V logic, but can be modified to TTL or 5...
We found this circuit in a 1972 documentation. The transistor, in fact, is a unijunction that can...