This power supply was found in a RCA publication from the 1970s. The circuit uses transistors from that time. Modern equivalent transistors can be used.
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...