The circuit was developed to produce a continuity tester with a low resistance mainly for checking the connections between soldered joints. Operational Amplifier (Op-Amp) – a DC coupled high gain ...

This simple but clever continuity tester sports two LEDs: RED LED = circuit resistance is < approx 10K, GREEN LED = circuit resistance <10Ω. It consumes approx 8mA from a 9V battery. When not ...

Some kind of continuity beeper has been a standard piece of gear since the dawn of electronics. Sure, you probably have an ohm meter, but sometimes you don’t care about the actual resistance. You just ...