PicoPSU Adapter Advice...

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starhawk

[H]F Junkie
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Oct 4, 2004
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I am the recent recipient of a PicoPSU-120, courtesy of a VERY generous fellow [H]er. I have a compatible power brick, but it is only rated 12v 8a (~96w). I would derate that somewhat, because it is from eBay and does not have a manufacturer's name spelled out on it that I can find... (it was advertised as a "90w" power brick so I probably wouldn't want to put more than a 7.5a load on it).

I want to power the following off of this combination of brick and PicoPSU --

- an HP MOCA-AR Mini-ITX motherboard
- a T7200 C2D CPU
- a 256gb SSD
- three fans (not counting the CPU fan via the mobo), specifically a 40mm fan on the chipset HSF, a 60mm*15mm, and a 120mm*25mm.
- a USB WiFi card (probably a Rosewill RNX-N600UBE).
- a USB flash drive (Centon DataStick Pro, 32gb) on a very cheap USB hub (IOGEAR GUH285).

The flash drive is more-or-less permanently attached to a hub because it had Close Encounters Of The Doorframe Kind... bent the connector a goodly bit. Easier to plug/unplug the hub than the drive.

So what I'm kinda asking is, will I be okay with that load on that combination of stuffs, or do I really need to upgrade the 12v brick to a 120w model?
 
Nobody knows?

FWIW, I emailed Mini-Box, who makes the PicoPSU, and I have not heard back...
 
Connect it and run it off a Kill-a-watt, check max Watts at the wall. If less than 80-90W should be OK.
 
Should be fine, I doubt that system would take over 60w unless those fans are mini jet engines
 
Just so I /know/ I'm in the clear -- anyone else want to chime in? I like hearing from more than one person...
 
Unless the fans are extremely high powered, I don't see any problems to power that build from that brick; as advice, I would use power bricks with class V or VI efficiency, which - indirectly - show you the quality of build.
 
The only real holdup is that the SSD I'm going to be using is currently in my laptop that I'm typing this on :eek: I use a weird kind of Linux that is quite portable between systems -- if things go the way I think they will, I won't even have to reinstall. I suppose I could pull the 64gb Transcend SSD from my netbook (backup sys) briefly -- would that be accurate enough for this?

Regarding the brick... it's cheap from eBay. Seller was 'InsideComputer' -- early last year. It's got a logo that's the letters 'ZW' in some sort of army-stencil style font in a box. I can't find any trace of a manufacturer name/marking beyond that on it. It has no references to efficiency, which means it's probably class P (for 'poo'). Probably made by Ziyong Wang Nohung Electronics (or, rather, something that sounds very similar :p ).

Model of the brick is ZW12V8A25RD. I've found no reference to it on Google except for some Russian-looking eBay gateway where there's exactly one listing for it.

If I can scrape together $16 I'll be getting a 120w brick from a different (cheaper) seller on eBay. No word on manufacturer but the housing looks suspiciously similar... it's got ribbing on the not-labeled-side which looks a /lot/ like my brick. The other difference is that the 120w brick has an LED to indicate when it's getting power... my 90w model does not.
 
If you don't look for a real silent build, you can mod an XBOX360 PSU, which I'm sure that you can get it for less, maybe even in your neighborhood; those PSU's are 130-200W, depending on model.
 
Actually, I can't -- I'm in a rural area, and I don't really talk to my neighbors much...
 
OK, check my math, folks... I'm fairly certain I'm in the clear, but again, check my math plz.

T7200 CPU -- 34w (from TDP)
i945GT NB -- 15w (from TDP)
ICH7M SB -- 3.3w (from TDP)
ADATA SP900 -- 0.9w (when active, 0.5w when idle)
Delta 60*15mm fan #1 -- 1.44w (on CPU HSF)
Xilence 40*15mm fan -- 0.72w (on northbridge HSF)
Delta 60*15mm fan #2 -- 1.44w (system intake fan)
Yate Loon 120*25mm fan -- 3.6w (system exhaust fan)
Rosewill RNX-N600UBE -- 2.5w (WiFi card; calc'd as max USB power draw)
IOGEAR GUH285 4-Port USB Hub -- 0.5w (see below)
Centon DataStick Pro 32gb Flash Drive -- 0.5w (see below)

TOTAL = 63.9w

Regarding the hub and flash drive -- according to this article, a USB hub without separate power (like my IOGEAR example) can only supply 100mA per port. Since a USB port on a computer can only supply a maximum of 500mA, and the hub is a four-port model, that leaves 100mA for the hub itself. That rule also conveniently provides a maximum power draw for the flash drive as well.
 
I've mentioned the 360 PSU because:
1. It's a good chance to get it cheaply/free;
2. Building quality is better(even the aftermarket ones) then the no-name power bricks.
One more thing which i would consider(my similar build has been modded) is to replace the cheap barrel connectors with XLR (male panel and female cable) both on the picoPSU and power brick.
Regarding your math: I don't see any problems, and the same applies to collected power consumptions.
 
I'm going to see if I can trade my 90w brick for a 120w brick at the local tech shop tomorrow -- I'm friends with basically the whole shop so it's possible...

Failing that I'll save my pennies for an XBOX360 brick. Looks like it's $10ish on eBay...
 
Went to the shop, got a ~140w brick. Was very very happy...

Got home a few minutes ago and looked at it.

19v.

*sigh*
 
@reb00tin -- I'm not a member of that forum so I can't see the pics :(

I think I'll be OK. Local tech shop has a KillAWatt, so I guess once I put the sys together I'll haul it over there and let them run it past the meter.
 
Mmm okay so my memory on the issue is foggy, but theres a system in my sig that was powered by the wide voltage picopsu (12-36v in) and a picoups with a 12v 7.5a SLA battery. The sla allowed me some engine off time for wifi/3g browsing and such, and helped filter the 14.1v input surge from a turning alternator.

The system was a cpu, usb wifi card, spinning wd scorpio black, 8gb m sata drive for a cut down xp install and a 2gb swapfile. All fanless. Under full music load (itunes with visualizer) it drew 5.1a from my 12v system.

I wouldnt run an epoxied and plastic power brick over 70% of its rated capacity. Ymmv. Thats me.

Also the picopsu fried both my intel motherboards eventually so i swapped to an android tablet.
 
I guess then it would be advisable to stick with the brick I've got, lol.

Just out of curiosity, do you know how/why your PicoPSU fried everything, twice?
 
Honestly, no idea... I'm assuming, though, the car environment with voltage spikes and sags just really didn't work with the pico PSU...
 
Most PicoPSUs just pass the main Voltage (Usually a 12v brick) directly to the board and derives the 5v and 3.3v from that 12v source. So if you have shit power going in, you'll have shit power going out. The wide range ones are abit different as they have to adjust the main voltage down first to 12v, then pull the 5v and 3.3v off. So they usually have cleaner output. The only way I'd ever expect the voltage to be clean enough in cars is to use a online UPS, and have the PCs power supply almost completely segregated from the cars power system.
 
That all makes sense. The PicoPSU-120's datasheet /does/ say "switched input" for the 12v line regulation... I guess that's the technical term for "pass-thru" these days...

OK, so I need to test the output from my brick (probably horrible). That's another excuse to set up the mid-70s Tektronix 422 o-scope that a phenomenally kind friend of mine (not local, but not an [H]er) sent me recently. I've been putting off learning how to use it, and I really shouldn't be...

Assuming for the moment that my current brick stains the screen with noise, how good are the XBOX360 bricks in that department, and are there any other recommended brick brands to look for/at? I need a 12v brick for sure -- and (since I'm crazy like that) I don't want to go below an output rated for 7.5a at 12v.
 
Worst case, it will crash at full load. If so get a PicoPSU AC adapter from Amazon ~$20. My i5 has been very solid with kit from Pico, the other photo in my link above is Phenom II x4 with 2 cores disabled! My only complaint, power jack comes off very easily.
 
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