The selected circuit was found in GE's 1977 semiconductor manual. 3N84 is a controlled silicon switch and SCRs support equivalents. The transistor can be a BC558, depending on the supply voltage.
This circuit was presented in a January 1990 Radio Electronics magazine article as part of a home...
The circuit shown is for testing both signal diodes (low current) and rectifiers (high current). The...
Found in 90s American documentation, this circuit generates an alternating voltage of 120 V x 150...