The circuit shown is for testing both signal diodes (low current) and rectifiers (high current). The circuit is from a 2000 Poptronics, and the transformer has a secondary winding of 100 to 300 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...