Go Down

Topic: PC PCU and common ground (Read 1 time) previous topic - next topic


Good afternoon,
I'm planning on powering my arduino from the 12v rail of a PC power supply.  I'll be powering other stuff (just a servo, intially) from the 5v rail.

To have a common ground will I need to use the same ground pin, on the same power chain from the PSU?  

I know from experience that the different power lines [by lines I mean the physical branches of power leads coming out of the PSU] coming out of a PSU are somehow separated (if I suddenly add load on one, something else on that line might stop working. Doesn't happen to devices on other lines) but I've no idea whether that's just because of serial/parallel difference or because there's something more complicated going on. And, more importantly, whether that means the grounds are on different lines aren't common.

Thanks. I hope this makes sense, I seem to have rambled a bit.

Jeff K

The grounds should all be common.  If they were not, I would think there would a lot of problems inside your computer.

If the power lines are somehow separately regulated or fused, it would most likely be on the positive side.
Jeff K - JKDevices.com - home of the MegaMini


All grounds on a PC power supply are common.

For why you need common grounds look here:-


I've read that page, grumpy mike, that's why I knew to ask :)

I wasn't sure it needed it inside a PC as the parts that are powered separately could quite easily cope with separate power supplies (presumably by sharing ground via the connecting cable, or isolating the communication cable. I dunno.  

Anyway, thanks for your answer :)

Go Up

Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

via Egeo 16
Torino, 10131