Pro/Forums

Pro/Forums (http://forums.procooling.com/vbb/index.php)
-   General Liquid/Water Cooling Discussion (http://forums.procooling.com/vbb/forumdisplay.php?f=9)
-   -   psu issue (http://forums.procooling.com/vbb/showthread.php?t=3133)

gmat 05-18-2002 09:02 AM

Quote:

Originally posted by DigitalChaos

id just rather use the existing heatsink network goin on in there to attach a block to.

Now that makes sense :p Just post pics for us when it's done...

BladeRunner 05-19-2002 12:26 PM

DigitalChaos has a good point as I also had an Antec 400 watt PSU but like the PC power & cooling he has it was far too cluttered internally to use for my project design / solution. The only issue with using the heatsinks that are already in the PSU is often they are live mains voltage (or at least one of them is). This would have the undesired effect of making the coolant live if a metal block was attached to it, (causing an earth trip or fuse to blow in UK mains systems.

I was thinking about a PC power and cooling 600watt or 650watt for future water cooling. Can't remember the model now but it's a double sized unit. not sure if it's server / duel CPU only. anyone have one of these?

DigitalChaos 05-19-2002 01:51 PM

hrm... good point about the heatsinks being live... i would imagine i could just connect one of those to ground and see what happens...

most of the mosfets apear to have a thermal pad between them and the heatsink which would stop the heatsink from being live...

also, i could just attach my water blocks with a big thermal pad to prevent electricity from flowing.

BladeRunner 05-19-2002 04:35 PM

I'd favour getting a Mulitimeter, (and someone that has the know-how to use it if you don't) to check the sinks for "liveness" rather than deliberately shorting it out.

The fact the mosfets have mica shims doesn't mean the sink is not live. The mosfets in the enermax were all shimmed but the sinks were live. I could find no definite reason why they needed to be live. Now the sinks are not there, and the block in the PSU is earthed with the mosfets attached to it also fully isolated with the same mica shims without any obvious downside. more about this in the PSU cooling build on my site.

gmat 05-20-2002 04:39 AM

I gave a thought to this heatsink problem, and the only reason i see for them to be live is EMI noise reduction (unless they're actually connected to the rest of the circuit).
Put 2 opposing sinewave signals in 2 opposing blocks of metal - in the middle you've got a flat line.
In this case maybe the sinks are live to compensate the unavoidable mains noise you've got on mosfets output.
The only way to work this out is with a good oscilloscope.

DigitalChaos 05-20-2002 07:57 AM

no, the reason they are live, is the design of most mosfets... the metal plate that attaches to the heatsink is live.

gmat 05-20-2002 08:38 AM

Wow never saw this kind of mosfet regulator.... usually the backplate is connected to GND meaning it's at 0V. Like BR said pick up a multimeter and tell us what's going on
:cool:

BladeRunner 05-20-2002 01:35 PM

gmat

I think it must be something like that as there has to be a reason. Like you say the metal back part of the Mosfets on my PSU is now & was before the water-cooling at 0v, it's the heatsink itself that was live mains voltage. The sink also wasn't being used as a bridge joining two parts of the PCB together either, as I checked for this.

The mica shims prevented the back part of the mosfet touching the sink directly, (as far as electrical conductivity is concerned),

I don't pretend to understand fully how a PSU works, but the water block is now earthed and the mosfets mounted in the same way with the same mica shims. It appears to work ok without the original heatsinks "liveness". Like you say a scope and someone that knows how to use it is what's really required :)

ct100 05-21-2002 04:47 PM

In some PSUs the Sink is used as a bridge between 2 Points of the PCB... I modified already 2 Enermax 550W where I had to soldier a bypass under the PCB...

But other than that reason there is no sense in live sinks...




I modified many Enermax PSU...

Here are some pics:

http://www.cooling-solutions.de/foru...axwakue2-1.jpg

http://www.cooling-solutions.de/foru...axwakue2-5.jpg

Heavy modified watercooled Enermax 550W:

http://www.cooling-solutions.de/foru...axwakue3-1.jpg

Another One:

http://www.cooling-solutions.de/foru...axwakue3-4.jpg

bigben2k 05-21-2002 04:52 PM

Nice!!!!!:)

BladeRunner 05-21-2002 06:24 PM

ct100

Interesting, as with my 550watt the power rail origin was the same point, so the bridging it would not have made any difference.

I notice that you have a copper "Cover" near that coil in mine that gets hot. Is it in contact with the coil?, I was intending to do something similar but wasn't sure if it might short something.

It can be seen in this image, it's the coil shown by the shorter Pink arrow, (click for large image).

http://www.zerofanzone.co.uk/picture...rmax1small.jpg

If this is possible I could easily run a copper plate to it from the side of the waterblock shown here.

http://www.zerofanzone.co.uk/picture...max3asmall.jpg

ct100 05-21-2002 07:37 PM

Enermax PSU's are very different, even if they have the same model no... so its possible you have another version of this PSU...

2 of my Enermax needed this bypass... without it, they could not provide 5V Standby Voltage...


This copper "Cover" is made from a 1,2mm thick copper plate, and does his job very good in cooling the Coil... no more 70°C+ now

I used AS2 under this "Cover" to make better contact to the Coil

http://www.cooling-solutions.de/foru...axwakue3-5.jpg

BladeRunner 05-22-2002 02:59 PM

Quote:

Originally posted by ct100


This copper "Cover" is made from a 1,2mm thick copper plate, and does his job very good in cooling the Coil... no more 70°C+ now

I used AS2 under this "Cover" to make better contact to the Coil


Does this not affect the coil. I would have though that it is a coil for a reason, so by connecting it with a copper plate and artic silver will make it less of a coil if you get my meaning, sort of shorting out one part to another.

ct100 05-22-2002 03:13 PM

It does not short the coil!

The copper wires of the coil arent pure copper... they have a very thin layer of shellac arount the copper... so they arent conductive at the surface...

AS2 isn't conductive, too...

so you dont have to worry about shorting something by covering the coil with a copper plate

gmat 05-23-2002 02:27 AM

The layer on the coil is a thin varnish. Any scratch on it and the copper will be exposed. For safety reasons i'd put an extra mica shim between the coil and the copper plate.....

DigitalChaos 05-28-2002 10:42 PM

1 Attachment(s)
well i took a volt meter to this thing.... and this is what i got.

the heatsink on the left has no voltage with the casing (ground)

for the heatsink on the right i got 120AC or 55DC with the negative lead on the heatsink and the positive lead on casing (ground)

these readings are for both the aluminum and copper sides of each set of heatsinks

DigitalChaos 05-28-2002 10:43 PM

1 Attachment(s)
now this little heatsink set scares me... i got this reading on both the copper and aluminum

750AC or 350DC with the positive lead on the heatsink and the negative lead on the casing (ground)

DigitalChaos 05-28-2002 10:45 PM

soooo.... looking at the way things are in there... im thinking about putting a quiet 80mm in there as a replacement.. and then put a hole in the top for a 120 or 92 mm to pull more air out.

Brad 05-29-2002 02:42 AM

I dare you to touch it ;)

gmat 05-29-2002 02:51 AM

Thats 2 fans, and 1 more than stock :rolleyes:
You just lose the purpose of modding that PSU. (reading your original post again...) If you want to get rid of noise, the solution is clearly not adding more fans...
BTW the readings you want are the AC ones. If the heatsink is acting like a bridge just disconnect it and replace it with a wire on the opposite side.
Again i doubt that copper part IS a heatsink. Looks REALLY like a EMI shield. It's hot because of magneto-resistive effects produced by the nearby coil.
And yeah there are some very high voltage parts in a PSU. Thats usually written on a big sticker :D (i know i know, us geeks just pop it open disregarding red & yellow hazard signs...)

Brad 05-29-2002 03:18 AM

a 55cfm 23dba 120mm and a 30cfm 22dba 80mm fan is much quieter than a 46dba 80mm fan ;)

DigitalChaos 05-29-2002 06:06 AM

Quote:

Originally posted by Brad
a 55cfm 23dba 120mm and a 30cfm 22dba 80mm fan is much quieter than a 46dba 80mm fan ;)
exactly my thoughts.... the stock 80mm is VERY loud

ct100 05-29-2002 07:20 AM

no fan is much quieter than any fan ;)

DigitalChaos 05-29-2002 10:10 AM

but the sound my $200 psu makes when you short out the heatsinks is byfar the loudest =)

DigitalChaos 05-29-2002 10:14 AM

Quote:

Originally posted by gmat
Again i doubt that copper part IS a heatsink.
well the copper part was cut to make little fins... also the other 2 main aluminum heatsinks also have this same copper finned heatsink on the opposite sides of their chips....



also... there is a series of air holes cut out of the casing next to this little heatsink

maybe its a dual purpose heatsink/emi shield



wouldnt it be cool to have a pcp&c engineer in here? he could tell us exactly what is and what isnt safe to be doing to it.... and exactly why some heatsinks are live and some arent.

gmat 05-30-2002 04:35 AM

If you happen to know an electrical engineer who's got access to a lab or at least an oscillo, bring the PSU to him he may tell you whats up :p PSU's are very easy to reverse engineer, they're all made the same so differences are quickly noticeable.

BladeRunner 05-30-2002 05:05 AM

Quote:

Originally posted by DigitalChaos


wouldnt it be cool to have a pcp&c engineer in here? he could tell us exactly what is and what isnt safe to be doing to it.... and exactly why some heatsinks are live and some arent.


I doubt it, probably just tell you removing the cover would void the warranty, and be horrified at the idea of water-cooling one :p

maskedgeek 06-01-2002 11:15 AM

iv been wanting to wc my psu, its only got 1 line of mosfets, and i havent got around to design my wb, but its gonna look similar to the heatsink, the heatsink is a big T, but im only worried about the conductivity, i was thinkinga bout getting non conductive aluminum...


All times are GMT -5. The time now is 07:36 PM.

Powered by vBulletin® Version 3.7.4
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
(C) 2005 ProCooling.com
If we in some way offend you, insult you or your people, screw your mom, beat up your dad, or poop on your porch... we're sorry... we were probably really drunk...
Oh and dont steal our content bitches! Don't give us a reason to pee in your open car window this summer...