Flip Flop 4027 (CB25120E)

This circuit was suggested by an article in the April 1988 Radio Electronics magazine. The flip-flop is of the JK type.

Triggered light source (CB7197E)
This circuit is from a 1968 General Electric manual. It produces a pulse of light when fired,...
Hall Sensor Metal Detector (CB15794E)
This circuit is from a 2001 Poptronics. The magazine no longer exists, but the components used are...
HFE meter (CB16983E)
This circuit is from 1990 documentation. It uses a bridge with LEDs and the potentiometer must be...