Simple continuity tester
this circuit is a countinuity tester, it could be used to test continuity of a wire or any kinds of conductors, the working of the circuit is simple, the T1 transistor will not get current in it’s base pin if a wire which you test is broken so you can assume that the wire you test has a cut somewhere inside it, but when you test a good wire the T1 will get sufficient current in its base pin so it turns on and the buzzer sounds. This circuit can also be used in the paths of a PCB to know whether it’s ok or not,
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