Most compact power supply JUST for hard drives

MikeMcLarenF1 · Post by **MikeMcLarenF1** » Sat Apr 08, 2006 2:35 pm

Alright here's the story. I'm building myself a dual-300Gb external hard drive enclosure with those IDE -> USB2.0 convertors, and instead of using 2 of those weak small external powerbricks, I want to have one thing that has just enough amps for the 2 Diamondmax10's. 12V 4A and 5V 4A is all I want, that works with a normal 120V input. I thought about using an ATX psu but then thats a bit big for an enclosure. If it's an ATX psu i'm using, then I have to build it INTO the enclosure. If it's an powerbrick, then I can make my case much smaller.

Does anyone know of any cheap external bricks that I can use?

Otherwise, is there a way for me to reduce the size of an ATX psu? like, which cables to cut off and if its safe enough for the hard drives if I do that.

Post by **MikeC** » Sat Apr 08, 2006 2:55 pm

3.5" HDDs draw on both the 12V and 5V lines, so a power brick is impractical, as few have more than a single output voltage line. You could just look for the smallest PSU to hack up. Two HDDs will not draw more than 40W total, so any old PC PSU made in the last couple decades (with 4-pin molex connectors) will do.

Shining Arcanine · Post by **Shining Arcanine** » Sat Apr 08, 2006 6:32 pm

You probably want one of these:

http://www.newegg.com/Product/Product.a ... 6812156101

MikeMcLarenF1 · Post by **MikeMcLarenF1** » Mon Apr 10, 2006 12:27 pm

MikeC wrote:3.5" HDDs draw on both the 12V and 5V lines, so a power brick is impractical, as few have more than a single output voltage line. You could just look for the smallest PSU to hack up. Two HDDs will not draw more than 40W total, so any old PC PSU made in the last couple decades (with 4-pin molex connectors) will do.

The powerbricks I'm talking about are the um.... ones that have molex connectors, like the ones that come with the external hard drive kits. As for the old PSU's, thats what I'm thinking about at the moment, but I need a small one that's as cheap as possible, under like $30 or something.

Shining Arcanine wrote:You probably want one of these:

http://www.newegg.com/Product/Product.a ... 6812156101

THAT is exactly what I have. Except, the power convertor on that thing only provides enough output for 1 hard drive. 2A each on both 12V/5V lines, not enough for 2 DM10's at once. I DO have them both running on one adaptor right now, and I haven't burnt it yet. but, I don't know how long it will hold. I'm not looking to replace the psu periodically due to overloading.

Does anyone know how to make a psu smaller? like.... which parts to hack off?

TomZ · Post by **TomZ** » Mon Apr 10, 2006 2:38 pm

MikeMcLarenF1 wrote:Does anyone know how to make a psu smaller? like.... which parts to hack off?

Not sure what you mean here. Any PSU design would be already have the minimum number of components to get the job done, due to cost considerations.

sdat1333 · Post by **sdat1333** » Thu Apr 13, 2006 12:48 pm

u dont hack off parts
just take off the cover and u usually have like an inch of air room

but as for PSU, what about this:
http://www.logicsupply.com/product_info ... cts_id/255

Howard · Post by **Howard** » Fri Apr 14, 2006 5:43 pm

http://www.mini-box.com/s.nl/sc.8/category.13/.f

atmo · Post by **atmo** » Fri Apr 14, 2006 11:24 pm

Something like this would work:

http://www.jaycar.com.au/productView.asp?ID=MP3108

It's an australian store, but you'd probably be able to get them somewhere a bit closer.

PositiveSpin · Post by **PositiveSpin** » Sat Apr 15, 2006 2:02 am

Using an ATX power supply may be problematic - some of them aren't stable unless there's a draw on the 3.3V line as well as the 12V and 5V lines. For that matter, some of them expect a minimum draw on the 12V line that may be higher than you'll be pulling.

Make sure you check the minimum draw specs for each line.

Trekmeister · Post by **Trekmeister** » Sat Apr 15, 2006 4:44 am

I have a couple of small PSUs I've ripped from old external SCSI enclosures which have one or two molex connectors. Perhaps you shoul look and see if you can find one of those in some random dumpster or some place selling old outdated computer equipment.
I can't see them having any problem powering a couple of 3.5" modern drives since they were usually make to power a full height 5.25" drive that draws huge amount of current.