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differentiate gnd from 0v on symmetric components

Posted: Thu Nov 30, 2017 4:09 am
by lagarkane
Hi Guys!

I read the article on polarity, and I'm still having one question:
If I have a symmetric component with 3 cables (vcc 0v and gnd), or even worse, If I have a non-symmetric component with 4,5 cables, that can also be used as a symmetric component (a PWM fan for instance, where you only want to make spin), how can I easily know which one is which, with only a multimeter and no wiring diagram?

I had this chinese fan with 3 cables. Using a multimeter I managed to find out which one was VCC, but then, I don't know how to distinguish between the 2 others. I don't even know if it matters which one I use.

Seems like a dumb question to me, I'm a bit surprised I didn't find the answer before posting here..
Looking forward to your answers!

Re: differentiate gnd from 0v on symmetric components

Posted: Thu Nov 30, 2017 3:24 pm
by DanV
You could have just googled "3 wire dc fan" and gotten more than a ton of results (5,670,000).