The following continuity tester schematic provides continuous audible indicator in order to keep an eyes on the probe circuit. The circuit has a response time which is very fast and could help make a lot of faster tests while listening to the beep. When responds to a definite short circuit with resistance less than 50 ohms, the beep will active. When the resistance value above 80 ohms, the beep won’t work.
continuity tester circuit schematic diagram