Power Supply A Guide to 12V PSU

Thehack

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So obvious now that you say it...

I will go with the C6, can't find anything smaller till now.

C6 is the smallest standard grounded AC cord. You can go with nonstandard connectors, just anything really, but they're more expensive and must be custom made.
 

BaK

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May 17, 2016
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You can finally count me in! :)
-> https://smallformfactor.net/forum/threads/12v-b01t3-a-3l-brickless-apu-build.15897/


While rereading that thread,
...
Also note that some DC-DC boards have additional cap filter circuit, or LC filter circuit.
...
I was wondering if the M2426 was doing such filtering?
Especially as I have another 12V build in progress, involving a MeanWell EPP-500-12 and its 187mVp-p ripple and noise which is above ATX recommendation of 120mVp-p.

I think I will anyway add an AC filter to be on the safe side:
Will one like this be ok?
 

gagarin61

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Jan 7, 2021
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How difficult/dangerous would it be to wire a 12V Mean Well PSU? My motherboard (ASRock Rack X570D4I-2T) takes an 8 pin 12V DC connector for power, and I need an 8 pin PCI Express connector for a GPU. The motherboard has a separate 4 pin connector for powering up to 5 SATA drives. Could I use for GPU power, or is this really stupid?

I'm looking at the Mean Well RPS-500-12-C (enclosed medical PSU), which can supply 320W with convection cooling only, with 91% typical efficiency.

My fears are related to the following:
  1. What are the most risky moments of the build?
  2. What should I definitely not miss and what should I think extra carefully about?
  3. What about the AC inputs? Can I encapsulate and insulate them for extra safety?
  4. What about ground?
  5. What about everything catching fire?
  6. Am I being paranoid?
Should I let someone else do this, or is it feasible for a complete amateur? I actually took a few electrical and electronics courses in high school, but I've forgotten everything. I have a good grasp of and a lot of experience building computers. But I have no real experience working with electrical wiring, etc.

Encouragement or discouragement is much appreciated. Thank you!
 

Thehack

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You can finally count me in! :)
-> https://smallformfactor.net/forum/threads/12v-b01t3-a-3l-brickless-apu-build.15897/


While rereading that thread,

I was wondering if the M2426 was doing such filtering?
Especially as I have another 12V build in progress, involving a MeanWell EPP-500-12 and its 187mVp-p ripple and noise which is above ATX recommendation of 120mVp-p.

I think I will anyway add an AC filter to be on the safe side:
Will one like this be ok?
The M2426 has some basic filtering but not enough to affect anything.

AC side filtering is important if you’re in an industrial setting with possibly crappy power or your local grid has “dirty” AC. A modern grid with a fairly modern home is fine.

Personally I think some out of spec ripple is okay as long as the unit has good transient response and regulation. All your components are powered by VRM anyways, and the regulation on those are tight, due to modern tech.
 

BaK

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The M2426 has some basic filtering but not enough to affect anything.
Ok, noted!

AC side filtering is important if you’re in an industrial setting with possibly crappy power or your local grid has “dirty” AC. A modern grid with a fairly modern home is fine.

Personally I think some out of spec ripple is okay as long as the unit has good transient response and regulation. All your components are powered by VRM anyways, and the regulation on those are tight, due to modern tech.
Thanks a bunch, I feel more confident now pulling the trigger with the MeanWell 500W!
 

quad

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Has anyone considered using a server PSU for this? They seem to be 12V single voltage and they're compact. They're very cheap on ebay! I just ordered a 750W HP 599383-001 for $14.89 off ebay just to try it as an experiment. I'm going to try to take the board out of the enclosure and cool it with a much larger diameter fan to make it quiet.
 

quad

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Has anyone considered using a server PSU for this? They seem to be 12V single voltage and they're compact. They're very cheap on ebay! I just ordered a 750W HP 599383-001 for $14.89 off ebay just to try it as an experiment. I'm going to try to take the board out of the enclosure and cool it with a much larger diameter fan to make it quiet.
PS If anyone is considering the same, make sure it's not one of the 200-277V input units (unless you have that in your house)
 

Thehack

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Has anyone considered using a server PSU for this? They seem to be 12V single voltage and they're compact. They're very cheap on ebay! I just ordered a 750W HP 599383-001 for $14.89 off ebay just to try it as an experiment. I'm going to try to take the board out of the enclosure and cool it with a much larger diameter fan to make it quiet.

Yeah lots of miners do it. From customer usability standpoint it is terrible (and liability). If it is a common model they sell breakout boards for it.
 

Valantar

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Has anyone considered using a server PSU for this? They seem to be 12V single voltage and they're compact. They're very cheap on ebay! I just ordered a 750W HP 599383-001 for $14.89 off ebay just to try it as an experiment. I'm going to try to take the board out of the enclosure and cool it with a much larger diameter fan to make it quiet.
There have been some experiments, but generally people aren't willing to gamble on buying used server hardware, particularly power supplies - they're too prone to failure. Stands to reason really, as it's likely been run at a high % of its rated load 24/7 for several years before being replaced. There's also noise to consider, of course, and the fact that they generally don't have any type of standard pinout. That being said, things like @petricor's fantastic S4MAX project wouldn't have been possible without using a server PSU. They got theirs new though, not used.
 
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BaK

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How do you guys manage to crimp the 160344-2 Ring Terminal Connector mentioned at the end of the first post, in the 'C. Wiring for Meanwell RPS-200-12/24-C' diagram?


I got mines from digikey:

And these terminals turn out to be made out of a thickness of 0.61mm (0.024"), which I am not able to crimp with my 16AWG (1.5mm2) plier (SN-48B):


These ring terminals just don't want to get bent, probably due to their thickness.

Did I order the wrong ones?
Or should I look for another crimper jaw that have a bigger teeth than 16AWG, event though I am going to use these terminals along with 16 or 18AWG cables?
 
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Valantar

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How do you guys manage to crimp the 160344-2 Ring Terminal Connector mentioned at the end of the first post, in the 'C. Wiring for Meanwell RPS-200-12/24-C' diagram?


I got mines from digikey:

And these terminals turn out to be made out of a thickness of 0.61mm (0.024"), which I am not able to crimp with my 16AWG (1.5mm2) plier (SN-48B):


These ring terminals just don't want to get bent, probably due to their thickness.

Did I order the wrong ones?
Or should I look for another crimper jaw that have a bigger teeth than 16AWG, event though I am going to use these terminals along with 16 or 18AWG cables?
I didn't use terminals like that for my ground connection, but wanted something with insulation specced for mains voltage AC, so I got something more like these (not the actual product). They don't need ratcheting crimp pliers or even a proper crimp die as the area for crimping is just a metal tube - anything capable of deforming the tube significantly in a small spot will do (I used a set of pliers similar to these, as they're made for just that purpose, but even a good set of pliers could feasibly do the job in a pinch). It's clearly a less strain resistant form of connection than a multi-wing crimp that wraps tightly around both the conductors and the insulation, but also much easier to deal with. It's not like ring terminals are typically pulled on much, so IMO it's fine, but I'm no electrician obviously. I used the same ring terminals and crimping tools for the AC input (L, N and GND) for the UHP-350-12 in my travel PC, and those have held up excellently.
 
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BaK

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Thanks for sharing your experience!
I could indeed switch to the kind of ring terminals you linked, I actually already have the right pliers for them. I know there are ones without insulation, so I can add a black heatshrink to them to stay in my color scheme.

I found them bulkier, that's why I went with the 160344-2 ones for my B01T3 build, for both AC and DC sides of the LSP-160-12T.

Will Investigate a little more and then choose between the terminals you linked (available quickly locally) or new pliers/jaw heads (coming from China and that I won't be sure are accurate before getting them).

Would be of great help if someone who already dealt with the 160344-2 ones could chime in.
 
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Valantar

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Thanks for sharing your experience!
I could indeed switch to the kind of ring terminals you linked, I actually already have the right pliers for them. I know there are ones without insulation, so I can add a black heatshrink to them to stay in my color scheme.

I found them bulkier, that's why I went with the 160344-2 ones for my B01T3 build, for both AC and DC sides of the LSP-160-12T.

Will Investigate a little more and then choose between the terminals you linked (available quickly locally) or new pliers/jaw heads (coming from China and that I won't be sure are accurate before getting them).

Would be of great help if someone who already dealt with the 160344-2 ones could chime in.
If the 160344-2 terminals are smaller that also likely explains why they are thicker, if their current ratings are similar at least. I can't say I looked too hard or long for this; I bought the ring terminals for my OptiplRX 570 build, and at the time got what I could easily get my hands on locally. (For the record, I actually had to trim them slightly to make them fit in the "wells" around the connectors on the UHP-350-12, as they were intially too wide.) That's a pretty low power build though, and for the ground connector in my HTPC I just used what I had.
 

BaK

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I just had a chat with the support from 'TE Connectivity', the manufacturer of the 160344-2 terminals I bought.
Great support btw compared to what I'm used to get with computer hardware supports. Their moto is indeed "Our top priority is to deliver an Extraordinary Customer Experience during each interaction that you have with our Customer Service organization." Heh!

Well, they told me that this kind of terminals, sold in reel, are supposed to be crimped by an applicator, such as this one:

o_O

Then I explained that kind of tool was a bit too much for my hobbyist needs, so he proposed the following to me:
Thinner ring terminals:

And another crimping tool:

Unfortunately, I noticed now that both product pages indicate "No distributors are currently reporting inventory for this product" :\

Anyway the 160344-2 terminals are obviously a no-go for us. See under, the 160344-2 terminals obviously need a good amount of force to be bent in a hand tool crimper.
I will let you know what I end up ordering instead.
 
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Thehack

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You can probably just use a semi standard jst style crimper. It won’t be exact to specs. Measure the width of the wings when they are pushed parallel and that is the width of the crimped you need.

Otherwise, I would just use the barrel crimps that can be crimped with any common stripper crimper combo.
 
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BaK

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You can probably just use a semi standard jst style crimper. It won’t be exact to specs. Measure the width of the wings when they are pushed parallel and that is the width of the crimped you need.

With my cheap crimper, I guess it's what you call a semi standard jst style crimper, process starts well but when the big wings reach the 'cellar' of the jaws, the wings just don't want to follow the curve and start to go back down.

No matter how hard I push on the crimper, there is no way to tighten it more.

This is where I get stucked.
We also see the little wings in the back, maybe also preventing me to tighten the crimper more
 

Valantar

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With my cheap crimper, I guess it's what you call a semi standard jst style crimper, process starts well but when the big wings reach the 'cellar' of the jaws, the wings just don't want to follow the curve and start to go back down.

No matter how hard I push on the crimper, there is no way to tighten it more.

This is where I get stucked.
We also see the little wings in the back, maybe also preventing me to tighten the crimper more
How much force have you tried applying? On some of the more challenging crimps I've done I've exerted more force than I was really comfortable with to get the jaws to close, and it's been fine. Be careful, of course, and back off if your tool doesn't seem like it'll take it.
 
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BaK

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How much force have you tried applying? On some of the more challenging crimps I've done I've exerted more force than I was really comfortable with to get the jaws to close, and it's been fine. Be careful, of course, and back off if your tool doesn't seem like it'll take it.

I always try to be cautious, but following your advice I went FULL force with two hands on the crimper, and....


The cheapo crimper has resisted, it did it!!!

Thanks a lot @Valantar, you're the man! 👑
I'm so happy I can go on with my build without having to hunt new parts!
 

Curiosity

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I've realized that while i'm pretty comfortable with 12v in general, I had a question I couldn't find an answer to yet.

3 prong vs 2 prong power connectors, for plugging into wall outlets.
I've seen sff builds and electrical devices done with 3 and 2 prong connectors.
Where is the line drawn that determines you need to go 3 prong instead of 2?

using an xt60/xt30 wouldl be a lot easier than an mr30 for me, but I recognize the importance of proper grounding.