Power Supply A Possible PSU Alternative

Krik

Minimal Tinkerer
Original poster
May 1, 2017
3
0
I am looking to build a custom ITX system. It will be replacing my dying laptop. One of the first things I wanted to try was to get an ITX system into about the same space as my laptop, it measures at 16.5 x 11.5 x 1.5 inches (420 x 292 x 40 mm). And after a bit of research and measuring I think I can build an overclockable water cooled gaming rig in that space. Only difference is the height, the case would need to be about 2 inches (52mm) in height. I may also mount a screen on it. As a more harebrained part of the project, later on I may explore options to disable the GPU and then run the system at a lower power setting to allow powering it with a battery (big maybe on this part).

Anyway back to my main point. As many here know finding a good PSU is a pain, the FSP500-50FSPT thread illustrates this very well. I think I also found somewhere in these forums a mention of the CPS-5011-1A1. For the last week I have been spending my evenings googling "500w PSU's" and the last few days I have been clicking every flex ATX and 1U server PSU in google images to try and find an alternative, that I can actually buy.

And then a couple thoughts hit me, "how tall are the actual components in a standard ATX PSU", and "if I removed the PSU enclosure would it fit the space requirement I have". Fortunately I have 20 or so old PSU's laying around, and some are partially dissected (for fun projects). So I measured the circuit boards and the height of the components. The circuit boards are about 110mm x 145mm. But their height is what we need, and they usually came in around 45mm to 50mm not including the height of fans or heat sinks. In fact if the PSU's had a second fan mounted on the top (bottom), the height of the heat sinks were also under 50mm. And I would have to guess SFX PSU's would be even shorter.

I am think of buying a PSU and pulling the board out of its enclosure (voids the warranty) and then mounting it on standoffs. To deal with the loss of the PSU fans (80mm to 120mm) I can add 50mm fans, in front and behind the PSU board. Good quality 500w PSU's start around $70, beating any price I have seen on the Flex ATX and U1 server PSU's. And really this option may allow the use of 600w, 700w, or even larger PSU's. And the real icing on the cake is you can get fully modular PSU's.

The only issue I did find that could derail this is that some PSU's had a secondary board mounted vertically that would exceed the 50mm height I am looking for. Now one could unsolder it and move it, but some may not be as comfortable with that. And really moving it is, likely, an unnecessary hassle if other units don't have the vertical board, or it is short enough. So the trick is finding out what the inside of these units look like. And manufactures don't typically take pictures of the inside of the PSU's, or provide measurements. So my thought is maybe some people here would be willing to open up their PSU's (it may void the warranty) and post pictures and measurements. Or maybe someone knows if some of the manufactures already have pictures or drawings with measurements of the inside of their PSU's, somewhere.

I think If I get time this week I may crack open a few, newer, PSU's I have access to and get measurements and pics and post them.
 

msystems

Master of Cramming
Apr 28, 2017
507
853
I am working on a similar project. SFX psu are 62.5mm tall and they all use 15mm slim profile fans. After confirming there are no other components which intrude in the fan area, this leaves a theoretical 47.5mm height (could be a bit less than this, depending on the unit).

If you look at the disassembly pages on jonnyguru and toms, you can see which SFX psus have daughterboards or components that are too high to be usable. Also the location of the AC input and whether it can be moved around is very important. The location of the AC input is different on every psu. Unfortunately the corsair SF600 has the AC stage mounted on a daughter board making it unable to be moved. Ultimately I went with the Enermax unit. On this unit, it looks like the AC input stage can be moved however is needed, and it can even be placed at a right angle to the modular output. Pics here http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=513

Still even if you find one that will fit, there is a lot of work to be done to create proper airflow and ensure that the heat is being dissipated properly, and also to build a new enclosure for it on the sides and top for safety purposes.

There is also the issue of properly bringing the AC wire into the case. The a4 case has an elegant solution to this where the AC inlet has an internal extension cable to reach the PSU but I have not seen this type of part for sale anywhere.
 
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Krik

Minimal Tinkerer
Original poster
May 1, 2017
3
0
Good to know about the Corsair SF600. My last few PC builds I have been quite impressed with Corsair and I was leaning towards that PSU.

On the air flow I found some 10mm thick 40 mm fans on Newegg if needed you could place 2 of them at the rear of the PSU, and 2 of them at the front of the PSU, and it would still be slightly shorter than the ITX motherboard. That's a lot of air movement especially as the PSU's usually don't have any thing bigger than a 120mm fan.

As far as the hole for the AC cord. I am just going to cut a square hole in the case. Then take the side of the PSU with the power plug, and cut it to fit the hole, and attach it.
 

Krik

Minimal Tinkerer
Original poster
May 1, 2017
3
0
A thought occurred to me this morning. If I plan to implement a battery option, using a DC-DC PSU could be very useful. So the G-Unique, KMPKT Dynamo, or HDPlex would all be great options. A couple of them paired with a Meanwell PSU could give me a lot of options. Having researched and used Meanwell products in the past I seem to recall them having battery backup units and programmable PSU's. All that would allow things like; charging the battery, turning off the graphics card, and switching over to battery power. With the graphics card off the PC should run well under 150W. The 18560 Lithium-Ion cell is a 3.7v 20A 3Ah battery. That means 3 batteries would get you to 11.1v and 222w, which should run the the PC for 15 minutes. So to get an hour you would need around 12 batteries, which I think I can fit into the various free spaces around the case. If I want to go for 2 hours I could make the case 0.75in (20mm) wider to accommodate more batteries.

Now tot he really the problem, finding any of the G-Unique, KMPKT Dynamo, or HDPlex units. It is great all these options are out there ,but if you can't buy them they are useless.

For now I am relegated to modifying and using a standard PSU. If those units become available at some point in the future I will further explore making my system battery powered.
 

Thehack

Spatial Philosopher
Creator
Mar 6, 2016
2,751
3,535
J-hackcompany.com
A thought occurred to me this morning. If I plan to implement a battery option, using a DC-DC PSU could be very useful. So the G-Unique, KMPKT Dynamo, or HDPlex would all be great options. A couple of them paired with a Meanwell PSU could give me a lot of options. Having researched and used Meanwell products in the past I seem to recall them having battery backup units and programmable PSU's. All that would allow things like; charging the battery, turning off the graphics card, and switching over to battery power. With the graphics card off the PC should run well under 150W. The 18560 Lithium-Ion cell is a 3.7v 20A 3Ah battery. That means 3 batteries would get you to 11.1v and 222w, which should run the the PC for 15 minutes. So to get an hour you would need around 12 batteries, which I think I can fit into the various free spaces around the case. If I want to go for 2 hours I could make the case 0.75in (20mm) wider to accommodate more batteries.

Now tot he really the problem, finding any of the G-Unique, KMPKT Dynamo, or HDPlex units. It is great all these options are out there ,but if you can't buy them they are useless.

For now I am relegated to modifying and using a standard PSU. If those units become available at some point in the future I will further explore making my system battery powered.

You can use mini box pico instead. The positive of using a meanwell 12V is you don't have to use a high end plug in DC board, as the regulation is mostly done by the AC-DC PSU.
 

msystems

Master of Cramming
Apr 28, 2017
507
853
Well, I did end up taking the Enermax out of it's cage and the measurements afterwards was 45mm in height which is pretty good.

Although it has no fan after this, i observed that it really didn't spin up the fan anyway unless the sustained load was over 250 watts. So I conclude that a basic ambient airflow should be enough to keep temps under control for low loads. Do this at your own risk though, its hardly worth it now with how good the nano psus are getting. There were a lot more difficulties than I anticipated because of how tightly all the parts and wires are crammed in there. And I have to make a new frame or cut the old one a bit to hold the modular board cause it is just sort of taped in place.