Projector Power Supplies

[JasonB]

Attachment 3833124 0------24 0

this is the same as -24 0 24 with the 0------24 being the ground point. Tie this to earth ground as well.

Might have the polarity backward so measure but the important thing is to see how the earth and 0V are tied together. USE vom to make sure what is negative and what is positive.
Make sure to tie the 0V and gnd of all other supplies to this central point as well.
Make sure the earth ground is connected to the mains earth as well. Add a wire even if the supplyes say earth ground.

... Umm wouldn't the 24VDC on that power supply on the right see a direct short to ground in this setup? I was thinking of something like this as well but I don't think it is possible with two independent supplies. Seems to me we would need a center tap transformer, where the center tap would be 0VDC bonded to ground .... Then rectify, regulate, and filter the +/- as required.

I hope I'm wrong, because it would be really nice to use independent inexpensive supplies to get the positive and negative rail.

[kecked]

Yes I was wrong and it made a hell of a problem for me. You can put the supplies in series as stated but not tie the center of the supplies to earth ground. It will make your life hell. Let it float. Works just fine that way. You just rely on the ac side earth ground on the supply cage for safety. The dc side is not an issue. You could most likely put your tongue on it.

[sean]

As I know some one uses one single PSU to produce high DC voltage (far higher than 48V) then DC-DC them down to many outs.

PSU is truly painful when building a compact projector.

[JRGixxerfreaK1]

There are high power module type PSU but cost alot! and requires good heatsink to the base and some little external component

here are some examples :
http://www.vicorpower.com/

http://www.tdk-lambda.com/products/sps/ps_pm/bodye.html

http://www.cosel.co.jp/en/products/sub04-13.html