Power Supply A Guide to 12V PSU

[Thehack]

There isn't a "200w mode." Like most PSU the output is sometimes temperature limited. It is a matter of it getting the required cooling.

You can try to use a fan from the motherboard header to see if that helps instead.

It may be for some reason that small current draw causes that terrible whine.

I had a 1700 and Rx 460 that ran gaming without coil whine. But that is just my experience. The system probably only consumed 130W.

 

[PackedPC]

Ok I'll give that a try. I'm building a mega compact render server with a e5 2683 v4 & 64gb ddr4 so I need all the power I can get haha probably post the build once I sort out this issue

 

[Thehack]

Ok I'll give that a try. I'm building a mega compact render server with a e5 2683 v4 & 64gb ddr4 so I need all the power I can get haha probably post the build once I sort out this issue

Good luck! If it ran fine without coin whine while the computer was on, then more than likely you won't have any issues. Just hook the fan to the motherboard so it only turns on when your mobo is on.

 

[PackedPC]

Thanks for the help dude, totally sorted now. Must of been the fan pass through that was causing the crazy whining.

 

[raksan]

While waiting for the case, my mean well 400 running combo with z2-atx-200 in naked form:

 

[chx]

Edit: nevermind, this was posted to https://smallformfactor.net/forum/threads/meanwell-external-ac-adapter-60w-280w-version.1659/ already.

 

[Thehack]

While waiting for the case, my mean well 400 running combo with z2-atx-200 in naked form:

One of us. One of us! Sweet setup and welcome to the 12V club.

 

[raksan]

@Thehack now I have a proper case, Lone L4, and I managed to put all components inside. The case has space just enough to fit the PSU, I'm more than happy with this. And I followed your guide by connecting the 12v from PSU directly to 8 pins cpu power (I only plug 4 pins, leave another 4 untouched) and 5v sata power is from pico psu. So far I used very little wires.

The computer run very stable, I didn't do any benchmark but I play game every night. The graphic card run hot though, but I'll fix it by replacing the heatsink and fan later.

 

[Thehack]

@Thehack now I have a proper case, Lone L4, and I managed to put all components inside. The case has space just enough to fit the PSU, I'm more than happy with this. And I followed your guide by connecting the 12v from PSU directly to 8 pins cpu power (I only plug 4 pins, leave another 4 untouched) and 5v sata power is from pico psu. So far I used very little wires.

The computer run very stable, I didn't do any benchmark but I play game every night. The graphic card run hot though, but I'll fix it by replacing the heatsink and fan later.

Sweet! You should post this in the L4 thread if you haven't.

Have you tried reversing the CPU fan? Since both fans are intakes, there are no nearby exhaust for the GPU heat. It may perform better as exhaust, as it seems like your CPU cooler is float type.

Also, I recommend you ground your AC power entry to PSU. Or connect it to the chassis, and check the resistance between the power cord and the PSU is less than 0.5 ohms. Don't want an electrical accident.

 

[NYCesquire]

What sort of voodoo would be required for this to run full-power components like a 250w GPU and 85w processor... fanless? Would you need multiple units? Could you replace the small included heatsinks with much larger ones?

 

[Thehack]

What sort of voodoo would be required for this to run full-power components like a 250w GPU and 85w processor... fanless? Would you need multiple units? Could you replace the small included heatsinks with much larger ones?

Are talking about the full build being fanless? If you're talking about just the PSU fanless, you should thermal tape some aluminum heatsinks, and locate it near airflow. You should buy the 400W version, and you should make big attempts to undervolt everything. GPUs and CPUs can have their power reduced by 30% for only 5% performance hit.

If you're talking about the whole case fanless, then fanless is in the opposite direction of SFF as you'd require huge-ass heatsinks to dissipate everything.

 

[NYCesquire]

Are talking about the full build being fanless? If you're talking about just the PSU fanless, you should thermal tape some aluminum heatsinks, and locate it near airflow. You should buy the 400W version, and you should make big attempts to undervolt everything. GPUs and CPUs can have their power reduced by 30% for only 5% performance hit.

I can solve the GPU/CPU etc being fanless. I'm asking specifically: How could I get a fanless meanwell psu up to 400 watts? Which components on the PSU would i need to heat sink? Would just doing that be enough? Would I need to run two PSUs to do it?

 

[Thehack]

I can solve the GPU/CPU etc being fanless. I'm asking specifically: How could I get a fanless meanwell psu up to 400 watts? Which components on the PSU would i need to heat sink? Would just doing that be enough? Would I need to run two PSUs to do it?

In that case you should try for the epp 400 and replace or add larger heatsinks. I'm not sure how much you should engineer for it to be able to cool itself.

 

[aquelito]

And it works !! Thanks @Thehack for the nice wire harness for my EPP-400-12. Works beautifully paired with a G-Unique board.
Sorry for the bad quality pic ; phone is broken.

I did not stop there and asked the very knowledgable C_Payne @ [H] to develop for me a custom +12V load switch I had in mind.

Thanks to this small MOSFET circuit (next to the multimeter), anything hooked up to an open-frame PSU is fed with +12V when the system boots.
This way, you avoid to power the GPU with your Meanwell PSU when the system is off.

Courtesy of C_Payne (c).

My successful test with my thin mini-itx system :

 

[0xdec]

And it works !! Thanks @Thehack for the nice wire harness for my EPP-400-12. Works beautifully paired with a G-Unique board.
Sorry for the bad quality pic ; phone is broken.

I did not stop there and asked the very knowledgable C_Payne @ [H] to develop for me a custom +12V load switch I had in mind.

Thanks to this small MOSFET circuit (next to the multimeter), anything hooked up to an open-frame PSU is fed with +12V when the system boots.
This way, you avoid to power the GPU with your Meanwell PSU when the system is off.

Courtesy of C_Payne (c).

My successful test with my thin mini-itx system :

That looks great! Do you have a schematic for the MOSFET switch?

 

[chribzzz]

I'am actually surprised the epp series work with pc gear that get direct 12v from the ac-dc. The dynamic load spec isn't great right?! (max 1200mv p-p) if iam not mistaking most pc psu's have like a max of 200mv p-p transient response. Anyone who has more info about this?

 

[Thehack]

I'am actually surprised the epp series work with pc gear that get direct 12v from the ac-dc. The dynamic load spec isn't great right?! (max 1200mv p-p) if iam not mistaking most pc psu's have like a max of 200mv p-p transient response. Anyone who has more info about this?

I looked into what you mentioned. The only pertinent spec I could find that ATX regulation specs is +/- 5%. Is there a special dynamic load specifications that ATX mentions?

Regardless, the chips also have their own DC regulation. These boards work fine even with regular external ac adapter.

 

[chribzzz]

I looked into what you mentioned. The only pertinent spec I could find that ATX regulation specs is +/- 5%. Is there a special dynamic load specifications that ATX mentions?

Regardless, the chips also have their own DC regulation. These boards work fine even with regular external ac adapter.

Thanks for looking into it.
So 5% reg is 600mv, these EPP meanwell are one the edge of the ATX spec. For the dynamic load you can search for some PSU reviews on tomshardware.com where they perform transient load tests. (these are not ATX spec but give a representation of the performance) I realy like the idea of less wire clutter but it's probably not that simple to find a good performing 12v supply that's around the 2% regulation like SFX and ATX supply's. Was thinking of a higher wattage build but it makes me nervous if it could wreck your HW. Do you think EPP could perform equaly compared to perhaps a corair SF600?
Stable voltages are good for the longevity of your HW right?

 

[Biowarejak]

Stable voltages are good for the longevity of your HW right?

Clean power delivery is vital.

 

[cmyk78]

I've been looking at 12 volt power supplies and found the TUNS700F12, would this work with a G-Unique?
There are 300 and 500 watt versions also, but since it's only 40 and 15 dollars more respectively, might as well go with the 700.
There are also heatsinks that look designed for these at ~22.9mm and ~11.4mm, which could be paired with some 60mm or 50mm fans.