Simple continuity tester


Posted on Feb 10, 2013

The pitch of the tone is dependent upon the resistance under test. The tester will respond to resistance of hundreds of kilohms, yet it is possible to distinguish differences of just a few tens of ohms in low-resistance circuits. Ql and Q2 form a multivibrator, the frequency of which is influenced by the resistance between the test points.


Simple continuity tester
Click here to download the full size of the above Circuit.

The output stage Q3 and Q4 will drive a small loudspeaker or a telephone earpiece.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Auto Loudness Control
Electronic dice with 7 LED
Electric Organ FOR ABOUT FIVE DOLLARS
fm tracking transmitter circuit
fm radio controller anti theft alarm
3volt fm transmitter for 88mhz
Window Lift/sunroof Lin 2.0 Slave Based On The Mc68hc908ey16 Microcontroller
NE5534 Integrated Circuits
Three-phase squirrel cage motor running single phase connection circuit



Top