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

Breadboard header for ATTiny
Triangle/Square-Wave Oscillator Serves Dual Purpose
Ultrasonic Proximity Detector
ADA4858-3 used as a PIN diode driver circuit
GH-75 type circuit hydrogen atom welder



Top