Found in the September 1982 issue of Radio Electronics magazine, this circuit triggers a relay intermittently. Triggering is done by a reed switch, but other types of sensors can be used.
The purpose of this circuit is to eliminate RF picked up by a turntable. The circuit is from a...
This circuit synchronized by the power grid can be used as a shield. We found it in an 80's...
This is a very simple version in which we simply fit the jacks, plugs with red and green LEDs,...