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 integrated circuit used in this project is not common today, but it can be implemented with more...
Found in an American publication from 1969, this circuit can be adapted to be used as a shield....
This current meter with many scales was found in a 80s American documentation. The operational amplifier...