Temperature controller LM3911 (CB21281E)

This circuit is from a Popular Electronics from the 90's. The circuit provides an output for a control stage.

Light Activated Switch (CB14457E)
This circuit is from 1968 documentation. We can assemble it with more modern components such as a...
Speaker protection (CB8193E)
Found in a 90s Silicon Chip documentation this circuit is intended to protect a speaker system in...
UV Sensor with UVTRON Tube (CB25942E)
The UVTRON tube is an ultraviolet radiation sensor. In this circuit from Radio Electronics from...