24v power supply out of computer psus?

So i watched a video a while ago, it was about turning a psu into a lab bench psu. The guy said you can run 2 of them together making 24v, having to cut the (earth)ground on one of them and have them running to the same outlet. So i can have the 24v but what about 3.3v and the 5v? im not really sure how those would work, wouldnt they just stay at their normal voltage levels?

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Yes you can use 2 PSUs and wire the 12V rails in series to get 24V. Nothing changes for the 3.3V and 5V rails.

would i need to split the cord coming from the wall? or just use 2 seprate cords

I did not see the video but it would be my guess he stacked the power supplies to get 24 volts.

So what happens to the other voltages depends on how you wire them.

They can stay the same or you can stack them to double there voltages like they did with the 12 volts to get 24 volts.

However I don't know why they would do that you get 24 volts when you connect from 12 volts negative to 12 volts positive.


You're limited by the current rating of the lowest current rail, so the -12V is usually around 1A, though the +12 is >10A. Put two +12 together, you get 24 @10A., put a -ve and a +ve, you get 1A.

You are limited by the current rating of everything.

guess i should of linked the video too.