Based on Radio Shack 276-137, this circuit was found in the December 1995 issue of Electronics Now magazine. The circuit drives an LED but could use a relay instead.
This highly sensitive circuit was found in a 1967 General Electric SCR manual. Equivalent...
This source of constant current was obtained in an American documentation of 1973. The transistors can be...
This common configuration source with diode bridge and single winding transformer was found in a...