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polarity tester Answered

if someone can help me
how to construct such a tool
polarity tester

Thank you in advance for helping


The polarity is marked on most batery cases,,,,,, Have you searched the automotive tech sites yet? In most but not all cases the negative pole is usually connected to the frame or the ground. circuit.

Use a voltage meter set to a range that it a range larger then the item your testing. probe the point you think is ground and the point you think is possessive. If nothing happens then the points have the same polarity. If you get a negative voltage then you have the points reversed. If you get a positive voltage then you have the right polarity.

If you want to make your own test probe anyway then google for a 'polarity test probe schematic'. There are many to choose from.

I tried to do a few devices from these links, but without success

http://elecfreecircuit.blogspot.com/2013/04/polarity-indicator-circuit.html http://www.eleccircuit.com/positive-negative-probe-with-ic-555/

The first one requires both a +12V input and a -12V input.

Also keep in mind that the power source for the probe and the power source your checking polarity on need to share the same ground in order for it to work.

Now I made another one with new parts, unfortunately not want to work,
if you give me instructions and schematics to make functional device, I will be infinitely grateful.