We found this circuit in an old documentation, but the components used offer no difficulty in obtaining it. The CMOS integrated circuits are powered by a 6V supply.
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...