With this circuit it is possible to vary the resistance by adjusting the mark/space reaction of the 555. The circuit was found in the November 1989 Radio Electronics magazine.
This circuit was found in a 1965’s General Electric documentation. It is intended for low voltage...
This protective circuit for power lines was found in a Radio Electronics from November 1957. The...
Found in the March 1974 Radio Electronics magazine, this circuit is designed to measure the level...