This circuit protects galvanometers that are excited by low impedance amplifiers. The circuit is from na old Electronic Design. The components are from the era.
We found this circuit on Radio Electronics from July 1990. It triggers a relay with a touch of the...
These three circuits have different treble responses. We found them in the February 1970 issue of...
This photoelectric cell light relay was found in Radio Electronics magazine from April 1958. The...