Suggested by Philips in 1966 documentation, this limiter can be found elsewhere on this website. The circuit is for 7 V, but can be changed to other voltages, depending on the zener diodes.
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...