High-power PicoPSU-like device

Brian · Post by **Brian** » Wed Sep 27, 2006 7:36 pm

(from the thread on Google's PSU proposal)

inti wrote:I was thinking about the PicoPSU for a new build I am doing, but I don't think it will have enough juice for the drives: I think the system will need more than 90W...

But a high current 12V source is going to need a very thick cable to keep down resistive losses...

I find this topic interesting. Google has given me some food for thought.

Here and here are two "high-efficiency" 12V power supplies. They're inexpensive, apparently fanless, and IME powerful enough for just even a high-performance gaming PC build. Unfortunately, I couldn't dig up a good data sheet on them. Then there's what amounts to a 200W version of the PicoPSU.

There. $80 for what appears to be a fanless, presumably high-efficiency, 200W PSU.

Maybe I'll try to find an AC to 12V converter with a better datasheet, and determine whether you'd actually have >80% efficiency. That would be the number to beat, correct?

On the mater of large currents at 12V: You can fit 20A through the little yellow wires in your PC. So I don't think that's going to be a problem.

EsaT · Post by **EsaT** » Thu Sep 28, 2006 12:51 am

Brian wrote:Maybe I'll try to find an AC to 12V converter with a better datasheet, and determine whether you'd actually have >80% efficiency. That would be the number to beat, correct?

Actually also that AC-DC transformer would need to have >90% efficiency if you want to have higher total efficiency as that available from good PSUs.

Then again normal motherboards draw power consumed by CPU from ATX12V connector so power draw from primary ATX connector shouldn't be big.

Brian wrote:On the mater of large currents at 12V: You can fit 20A through the little yellow wires in your PC. So I don't think that's going to be a problem.

Remember that inside PC all heavy consumers have multiple wires, for example three in case of PCIe.
If you would put that 20A through one wire insulation and connectors mights start to melt... even continuous 10A would be very propably enough for heating thin contacts like those used in connectors inside PC.

Just check three phase power current connectors rated for such currents.

jamesavery22 · Post by **jamesavery22** » Mon Oct 02, 2006 12:09 pm

I'm actually looking at building a similar project. Even if I don't end up having a need for it, its a curious little project.
I want to have a quiet little box to put in my bedroom. So I thought of using the PW-200-M to power a small Pentium M box.

I probably won't end up doing this so I'll just say how I would do it

parts:
2hz P-M
ASUS N4L-VM
2gig ddr2 kit
x1600 w/ hdmi
2 x dvico fusion tuner
seagate momentus laptop sata drive

Hook it all up and use a spare ATX PSU I have laying around and start measuring actual current draw of each line with a clamp-on-meter. Write down all the draws at peak and tally them all up.

I'm guessing at a full load (F@H running and MCE recording two shows) that will pull more than 200w total. Let alone only 6A on 3.3v 6A on 5v, and 12 on 12. So unplug a tuner or both, try integrated graphics, see what crap on the board you can turn off, use only 1gig, try a 1.8 -1.6 P-M etc etc. Keep measuring until all loads are comfortably within the pw-200's specs way before you buy it

Would be really fun just doing that part. Let alone building a custom case to keep everything cool and quiet. So have at it Brian

qviri · Post by **qviri** » Mon Oct 02, 2006 12:17 pm

jamesavery22 wrote:I'm guessing at a full load (F@H running and MCE recording two shows) that will pull more than 200w total.

Why?

jamesavery22 · Post by **jamesavery22** » Mon Oct 02, 2006 1:41 pm

qviri wrote:
jamesavery22 wrote:I'm guessing at a full load (F@H running and MCE recording two shows) that will pull more than 200w total.
Why?

Others have tried and failed. When the PW-200 more than a few people tried this. Sure a 3ghz p4 can be powered with it, but no peripherals and full load won't be stable. This was close to 2 years ago. I was looking at making a 2.4ghz P4 box with a single harddrive and nothing else. I have no clue what forum I was asking on at the time but I had found someone who had damn close to the same setup I was going to try. He had already messed around with a PW-200. It worked to the point where he could install windows, but rails weren't stable enough to run anything.

Using a <2ghz P-M will make a big difference, but with all that stuff I'm guessing one of the rails is going to be overloaded. Just guessing though I have no way to back it up. Hence why I would do the measurements

--edit

Just checked my p4p800se 2.1ghz P-M box, the BP420S it's on says at close to full load its getting a 33% load, and its max is rated at 260W so 85.8W if its accurate, I dont know if it is though. Thats a p4p800se with a gig, two samsung 2.5" drives, a pioneer DVD player, a 9600xt, and a Theater 550 pro

jamesavery22 · Post by **jamesavery22** » Fri Oct 13, 2006 9:59 am

Well holy shit I got lucky and I'm going to build this HTPC after all

Heres what I'm aiming for:

Any core solo/duo I can get cheap
ASUS N4L-VM
1GB PC2-5300 stick
Video card? Really not sure. Think I'm going to go with a 7600GT. Depends on how I make the enclosure though. If I make it so it needs to be low profile(leaning this way) then Im stuck with a x1300 or a 6600. I need DVI.
1 x dvico fusion tuner
seagate momentus laptop sata drive

Anyone ever find a good place to buy that 12v 200w brick?

smilingcrow · Post by **smilingcrow** » Fri Oct 13, 2006 10:51 am

jamesavery22 wrote:Anyone ever find a good place to buy that 12v 200w brick?

What country are you in?

jamesavery22 · Post by **jamesavery22** » Fri Oct 13, 2006 11:22 am

USA.

I probably shouldn't look for a specific power rated brick until after I know what my needs will be...

gmontem · Post by **gmontem** » Fri Oct 13, 2006 11:50 am

USA resident looking for a place to buy a 12v brick as well, at least 200 watts, to be used with the PW-200-M. I want to see if I can use an external PS with my Shuttle SN21G5.

The Shuttle eBay store sells a 220 watt external PS but the connector from the brick to the Shuttle is a little different. There's a pic of it in the spcr review of that Shuttle that uses this brick for those interested.

The bit with sending 20A through a small number of yellow wires concerns me. Will a couple unused Y splitter cables deal with this problem?

Aris · Post by **Aris** » Tue Oct 17, 2006 12:36 pm

Never knew shuttle had an ebay store.

Heres a link to the 220w external PSU from shuttle.

http://cgi.ebay.com/SHUTTLE-PS220-220WA ... dZViewItem

Its a rebadged Delta 220w. Occasionally you can find these rebadged delta's used from dell for like $30. You will need to have some soldering skills to use them however, as you need to change the connector on the end of it to work with a more standard connector on the DC/DC adapters.

jamesavery22 · Post by **jamesavery22** » Thu Oct 19, 2006 7:09 am

Thank you Aris! Never saw the SPCR review of the Shuttle that uses that.

For anyone else searching for one here are the model numbers shown on the label in the pic from the SPCR review:

PC46X220D SADP-220DB-B

First gets 0 hits but ther second gets some in Europe and eBay.

AznJason · Post by **AznJason** » Sun Oct 22, 2006 3:30 pm

The Dell equivalent is the DA-2 (220w)

http://search.ebay.com/Dell-DA-2_W0QQfk ... lQ20DAQ2d2

Mats · Post by **Mats** » Sun Oct 22, 2006 11:42 pm

jamesavery22: Dunno if I'm pointing out the obvious, but in the first post you wanted a PM, which doesn't fit the N4L-VM, then you said Core Duo, which should work with it.

jamesavery22 · Post by **jamesavery22** » Mon Oct 23, 2006 9:47 am

Mats wrote:jamesavery22: Dunno if I'm pointing out the obvious, but in the first post you wanted a PM, which doesn't fit the N4L-VM, then you said Core Duo, which should work with it.

Yeah I meant to point out my mistake before. Realized P-M won't work with the 945GM board

Doh. Been hunting for Core Duo's ever since. I missed Newegg's open box deal on the N4L-VM for $80 last week. Another Doh...