Cable tester

Conductor tester for checking two or more conductors /in buildings or machinery/.
Tester designed with integrated circuit LM324-U1 four functional amplifiers.
D4 is used as a sensor and it initiates at the opposite end of the circuit under test.
Pushing B1 pushbutton starts the tester.
Power supply: 9V battery.
Broken conductor indicator.
Misconnected conductor indicator.
Short-circuit conductor indicator.
Normal conductors indicator.