Power Supply A Guide to 12V PSU

[NateDawg72]

Interesting I have no issues with my PicoPSU 160XT and EPP-200-12. It does take about 15-20 seconds after plugging in power before the CPU will boot, not sure if it has to charge some capacitors or something like that.

It might be something that varies per motherboard
In regards to booting, I haven't had it not boot yet and I hit the power button about 1 second after flipping the switch on the AC side

 

[arataisozaki]

@NateDawg72 : still my awfull test bench !



The direct plug unit is directly wired to the EPP-400-12.
The One2 board is also powered by the EPP-400-12, in "always ON" mode.

Maybe I should try to power the direct plug unit through the "always ON" 4-Pin connector of the One2 to avoid cold boot issues ?

Indeed, on some occasions, the LED power of the motherboard will light up then shut down immediately.
The 180mm fan will continue to run but the pump won't start.
No POST.

I have to manually shut down the AC Line then wait and press again the power button to be able to boot.

What kind of inline connectors could I use to extend both 12AWG silicon wires of the direct plug unit ?

@arataisozaki @Thehack : this is the kind of solutions you were mentioning end of October right ?

Yes, that is exactly what we were talking about Nice to see it actually works!
Why do you have 12 AWG wires on your direct plug unit? I think the One2 takes all the wattage. There shouldn't be more than 10 W be going to your direct plug unit. You can just desolder them and put longer smaller wires in there...

 

[dEuuCe]

Nothing fancy:
Old Maximus VI Impact w/ 4790k CPU
Zotac 1080 Mini
picoPSU-160-XT

All (3) power inputs are wired in Parallel to a Meanwell EPP-400-12

No boots issues for me, cold or otherwise.

 

[Choidebu]

How exactly do you wire that? Does your gpu not turning itself on all the time even if the mainboard does not? I can understand eps being on all the time is no problem, but gpu?

Sorry this thread have been challenging my pc-electrical-common-sense all the time..

 

[aquelito]

@arataisozaki : this unit was built last year for an other build. I'm just borrowing it but I'll ask the permission to adapt it

I'm also working on a separate PCB to be able to control the Meanwell EPP-400-12 with your power switch.
For me, it's the most universal and cleanest way to use a MW.

Haven't been able to get it work though...


I wanted to test a Meanwell EPP-300-12 but, from the spec sheet, that PS_ON connector pinout of the EPP-300 is the exact opposite of the EPP-400.
Connectors are also different.

I hope it's just an errata from the spec sheet. Otherwise it's just a stupid design choice from MW.

Will have to confirm that with a multimeter.

 

[smitty2k1]

How exactly do you wire that? Does your gpu not turning itself on all the time even if the mainboard does not? I can understand eps being on all the time is no problem, but gpu?

Sorry this thread have been challenging my pc-electrical-common-sense all the time..

This also confuses me but intrigues me as I have an ASUS Impact VI and 4770k myself.

 

[NateDawg72]

How exactly do you wire that? Does your gpu not turning itself on all the time even if the mainboard does not? I can understand eps being on all the time is no problem, but gpu?

This also confuses me but intrigues me as I have an ASUS Impact VI and 4770k myself.

That's similar to how I've wired my EPP-400-12. It isn't much of a problem with the GPU because there won't be any load but fans and LEDs may turn on. With my particular GPU I don't have any fans or LEDs plugged in since my fans are using a 4pin header on my motherboard so I don't even notice

This is an old picture from when I used PicoPSU 160XT

 

[dEuuCe]

How exactly do you wire that? Does your gpu not turning itself on all the time even if the mainboard does not? I can understand eps being on all the time is no problem, but gpu?

Sorry this thread have been challenging my pc-electrical-common-sense all the time..

This also confuses me but intrigues me as I have an ASUS Impact VI and 4770k myself.

The 8pin CPU power is wired to the 12v Meanwell
The PicoPSU power is wired to the 12v Meanwell
The 8pin GPU power is wired to the 12v Meanwell.

I just have some wago connectors bridging the leads at the MeanWell to keep it clean, I can take a closer picture of the connectors when I get home if someone would like...

While the 8pin GPU connector might have live power, The GPU isn't pulling any power over that connector while the PC is off; at least mine doesn't. I can't speak to the ATX specification, just to what I've observed.

Same goes for the 8pin CPU connector, if the motherboard isn't "ON" it's not pulling power over that connector.

 

[Choidebu]

So it's not that they don't 'turn on' but your particular gpu does not? Because this why people use load switches is because on mining, where they use multiple psus to power gpus separate from motherboard. Some gpus would start their fan immediately when they receive power, so I guess it depends on the power design?

I mean, with psus you get specs that states idle power consumption when no load is connected. No such spec with gpus, so your card might very well consuming phantom watts just being connected to live rail.

 

[dEuuCe]

So it's not that they don't 'turn on' but your particular gpu does not? Because this why people use load switches is because on mining, where they use multiple psus to power gpus separate from motherboard. Some gpus would start their fan immediately when they receive power, so I guess it depends on the power design?

I mean, with psus you get specs that states idle power consumption when no load is connected. No such spec with gpus, so your card might very well consuming phantom watts just being connected to live rail.

Fair enough...

I unfortunately have no experience, first or third hand, in regards to the mining context you alluded to, so I can't confidently speak on what's happening.

I can confirm, when testing the power consumption of my Zotac 1080 I had my multi-meter between the MeanWell and the GPU, there was no power flowing to the GPU while the PC was off.

Sounds like it depends on GPU card(s) at play; there could be, and will be, variations in power consumption between AMD and Nvidia cards, cards across different series, even cards in the same series. Determining those variations consistently is going to be a challenge without more data.

I have a couple other video cards I will test in a little while and post the results.

 

[Thehack]

So it's not that they don't 'turn on' but your particular gpu does not? Because this why people use load switches is because on mining, where they use multiple psus to power gpus separate from motherboard. Some gpus would start their fan immediately when they receive power, so I guess it depends on the power design?

I mean, with psus you get specs that states idle power consumption when no load is connected. No such spec with gpus, so your card might very well consuming phantom watts just being connected to live rail.

The gpu doesn't actually turn on. Just the fan and led.

The GPU, and the power controller itself, needs to 'wake' to be on. If the PC is off, those components are off.

The switches only serve the purpose of avoiding this issue.

Mining PSU uses a 24 pin adapter or always on mode, to detect when to supply power.

 

[aquelito]

If I were to watercool a Meanwell EPP-400-12, how would it be done ?

- Replacing the original aluminium heatsinks like this ?

- Or simply screwing the Meanwell to a HDD cold plate ?

 

[Supercluster]

Spoiler

If I were to watercool a Meanwell EPP-400-12, how would it be done ?

- Replacing the original aluminium heatsinks like this ?

- Or simply screwing the Meanwell to a HDD cold plate ?

Count me highly interested in the HDD water block method, and the data of your findings, with any method, when it goes live.

 

[arataisozaki]

Just one thing to mind: I think I read somewhere in the datasheet that the different heatsinks of the meanwell must not be electrically connected.

EDIT: Just confirmed. "HS1, HS2, HS3, HS4 can not be shorted"

 

[Wenemun]

hi guys. For those interested I whipped up a EPP 400-12 in sketchup. It's accurate to the data sheet plans, but not sure if it matches the real thing. Obvs not all the board components are there...

https://smallformfactor.net/forum/threads/meanwell-epp-400-12-ac-dc.9733/

 

[McSpain]

Edit2:
First found this adapter and thought it was standard sized. Then realised, that my MeanWell RPS-200-12 doesn't have any info about fan control. Do MeanWell PSU's power down their fans withou load, or do I need a load switch to trigger it only, when the computer actually draws power?

 

[Thehack]

200W does not have a fan output.

The 400W does. It is simply on/off.

I'd connect the fan to the chassis header to control it when the pc is on and via bios.

 

[McSpain]

200W does not have a fan output.

The 400W does. It is simply on/off.

I'd connect the fan to the chassis header to control it when the pc is on and via bios.

You mean the fan header of the 200 isn't controlled but always on.
I might hook up the PSU fan to the 12V output from the SATA connector, which is unused anyway. Will need to do some crimping today...

 

[Choidebu]

I found an ebay deal on 500W TDK psu, GWS500-12, for 53 AUD!

It's a bit big, 240x105x41, and fans, but all other specs looks good. 150mV ripple, remote sense and remote on, even has output programming (whatever that is).

Just posting here if anyone from down under interested, as I'd not know what to do with it even if I got it.

Edit: forgot the link.

 

[aquelito]

I also have this in my eBay watch list, but pretty huge :
https://www.ebay.com/itm/NEW-TDK-La...upply-500W-12V-41-67A-Open-Frame/264065831905

@Thehack : did you make a post on how to correctly ground an open-frame PSU ?

EDIT : https://smallformfactor.net/forum/threads/electrical-safety-thread.8108/

Simply connecting the Ground prong of the AC connector to one of the Meanwell standoff hole with a 16AWG wire is enough ?