This circuit tests the reverse voltage of power diodes. The transformer is high voltage and so are the rectifier diodes. The circuit is from a 1976 QST magazine.
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...