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.
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...