This circuit with the CA3059 was found in the July 1995 Elexctronics Now magazine. The signal must be DC, and the circuit is not isolated from the mains.
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...