Design me a single 12v output PSU

Aris · Post by **Aris** » Thu Mar 15, 2007 7:17 am

Ive had study in electronics and powersupplies before, but its been so long since i learned about them, and actually used that knowledge that i forgot how to do this myself.

I was thinking of getting one of those PCB boards from radioshack that you can solder devices into and create your own circuit boards.

Can someone draw me up a diagram and a parts listing of what i would need to convert wall 120v AC into a single 12v ouput with around 25amps?

I'm hoping i can make it small enough to put into a small plastic box, with some heatpipes attatched to heatsinks to cool the hot parts, with a quiet 120mm nexus undervolted to keep it cool. then use it as an external "brick" to power my PC's.

Since it seems like no manufacturers out there currently have any desire to create a product like this, i figure i might as well try to make one for myself.

Post by **MikeC** » Thu Mar 15, 2007 7:40 am

That's not a simple task, afaik.

You might contact cpemma, a member here who has extensive electronics knowledge -- http://www.cpemma.co.uk/

Zinj · Post by **Zinj** » Thu Mar 15, 2007 8:33 am

Any reason not to consider an open-frame power supply? Companies like Telkoor, XP power, and some others make single output supplies in 3x5 inch 1u form factors that come close to or exceed 25 amps. Just a thought.

Zinj

flyingsherpa · Post by **flyingsherpa** » Thu Mar 15, 2007 9:14 am

making your own won't be that easy and you can already buy such things off the shelf. i have a 12amp one that i use to power a special battery charger used mainly for r/c (radio control) battery packs. look around, you can find these things, just don't look at 'computer power supplies'. i think i found mine on a hobby website. i know radioshack has some but i doubt they go up to 25amps. if you need that much power, it's going to be pretty big and heavy... like shoebox big and 10-20lbs, but it will likely be passive. also, amateur radio guys use supplies like that, so look on their websites too.

i'll try to remember to look at mine when i get home tonight and link to where i got it.

Oleg Artamonov · Post by **Oleg Artamonov** » Thu Mar 15, 2007 12:29 pm

www.tracopower.com -> TOL 300-12.

Zinj · Post by **Zinj** » Thu Mar 15, 2007 1:09 pm

Telkoor EFO306-112. This is pretty new and no clue about availability, but they claim 29 amps (350W) on a single 12v rail, 83% efficiency at 110ac, and only 181x98x36mm in size.

http://www.telkoor.com/SpecProd.asp?info_id=4373

wwenze · Post by **wwenze** » Thu Mar 15, 2007 3:27 pm

Zinj wrote:Any reason not to consider an open-frame power supply?

Because I f***ed myself before with an open-frame PSU placed on top of my computer casing.

And I live in 230V country.

But maybe it would be much safer if inside the casing.

Zinj wrote:I was thinking of getting one of those PCB boards from radioshack that you can solder devices into and create your own circuit boards.

I highly doubt those breadboards can handle 25 amps.

Anyways, here are some resources to help you build your PSU or completely put off the idea altogether (hopefully not since you studied before):
http://www.hardwaresecrets.com/article/327
http://www.smps.us/

Good luck, I hope that one day I'd get to understand this s***. After all I want to study electronics.

(damn I think I just lost some brain again reading the site)

Zinj · Post by **Zinj** » Thu Mar 15, 2007 7:26 pm

I was definitely thinking in terms of putting the open frame in a custom enclosure, not leaving it out where you could shock yourself.

Is there any reason why you couldn't do something like this, using the 12v feed to directly power 4 pin and 6 pin connectors for cpu/video card and a pico-psu or similar to step down for 3.3 and 5v? Basically have an external brick capable of powering a medium power system with higher end graphic setup?

Aris · Post by **Aris** » Fri Mar 16, 2007 4:51 am

i researched up a bit. it would have to be a linear PSU, not a switching. It seems that the components for a switching psu need to be much closer together than i could do as a DIY project.

I'm still interested in building it though, if for no other reason than to see if i can.

Oleg Artamonov · Post by **Oleg Artamonov** » Fri Mar 16, 2007 5:31 am

Aris wrote:i researched up a bit. it would have to be a linear PSU, not a switching

300W linear PSU? 10 kg weight and 50% efficiency?

Are you joking?..

wwenze · Post by **wwenze** » Fri Mar 16, 2007 6:29 am

300W linear PSU, 25A +12V output on a single rail, + cannot use existing power supplies (like the Silverstone ST56ZF)

Now I'm curious, what are you using it for?

Aris · Post by **Aris** » Sat Mar 17, 2007 1:16 am

do i HAVE to use it for anything? why cant i just want to build it for the hell of it?

Design me a single 12v output PSU

Design me a single 12v output PSU

Off the shelf?

Re: Design me a single 12v output PSU

Another possibility

Re: Off the shelf?

open frame