This circuit appeared in the 1991 Electronics Experimenter Handbook. The circuit is for remote controls of the time that are slower than today's and may not work with modern types.
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...