This circuit indicates when current is flowing in a battery charger circuit. The circuit was found in the June 1984 issue of Radio Electronics magazine.
This circuit is from a publication from the 70s, but it can be assembled with any diac and a Triac...
Found in American documentation from the 1990s, this circuit generates signals in the 350 to 500...
This circuit was found in a Radio Electronics from October 1952. The circuit equalizes the sounds...