This circuit is from a 1980s Motorola documentation. The circuit can be made with modern equivalent components. The original circuit is for the 115 Vac (110 V) grid and has two settings.
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...