This circuit was found in American documentation from the 90's. The transformer determines the output voltage. The transistor must be equipped with a heat sink.
This circuit is from 1968 documentation. We can assemble it with more modern components such as a...
Found in a 90s Silicon Chip documentation this circuit is intended to protect a speaker system in...
The UVTRON tube is an ultraviolet radiation sensor. In this circuit from Radio Electronics from...