Power Supply LED AC-DC 12v PSU

[Max Harrison]

Hello all! This is my first post so please feel free to inform me if there are any guidelines I'm not following correctly.

Anyway, I've seen these LED AC-DC PSUs laying around, they provide 12v @ up to 33A. I was wondering if these could conceivably power a small pico PSU for the motherboard and power the rest of the build directly via custom EPS/VGA cables off of the 12V rail from the ac-dc psu? Thanks.

 

[Piewalker]

I've wondered the same thing -- if an ultra thin 12v LED driver unit would do the trick or if the output isn't filtered and doesn't meet ATX current ripple standards needed for stability. I would think it'd be fine pairing with a Pico for the motherboard and bypassing the pico straight to the GPU. But I'm not sure if they have over-voltage correction and if they're solely passively-cooled. And what is their efficiency? Give me a Platinum and I'd be interested. The fact that most have terminal interfaces is great and is a step up on network server PSUs, which use proprietary gold finger or other type of connectors for output and control. Those are more difficult to deal with but have higher power output generally than LED drivers. But if someone can point out a reasonably small 12v LED driver PSU above 50a (600w), it may be worth considering if it could fit in a SFF build, at least for testing/proof-of-concept.

 

[Max Harrison]

I've wondered the same thing -- if an ultra thin 12v LED driver unit would do the trick or if the output isn't filtered and doesn't meet ATX current ripple standards needed for stability.

That's my worry, I'm worried it just isn't stable enough, as there is a difference between just powering an led and powering a computer in terms of required accuracy. They're only like 25 euros shipped so I might give it a crack and read of the voltages and see what it delivers on an old test board.

I would think it'd be fine pairing with a Pico for the motherboard and bypassing the pico straight to the GPU. But I'm not sure if they have over-voltage correction and if they're solely passively-cooled. And what is their efficiency? Give me a Platinum and I'd be interested.

I'm reasonably well versed when it comes to electronics, but am still not too experienced, I'm only 20 years old, all though I have been tinkering with computers/tech since about the age of 9, but I wouldn't know how to test for the over-voltage correction - or even what that's explicitly used for aha -

In terms of efficiency I'm not too bothered, I will probably not use the full 400w yet also, but I'd rather have more wattage ready for the inevitable upgrade.

The fact that most have terminal interfaces is great and is a step up on network server PSUs, which use proprietary gold finger or other type of connectors for output and control. Those are more difficult to deal with but have higher power output generally than LED drivers. But if someone can point out a reasonably small 12v LED driver PSU above 50a (600w), it may be worth considering if it could fit in a SFF build, at least for testing/proof-of-concept.

I fall into a rather specific case here, as my build is definetely SFF oriented, but not all that small. I'm going for a full custom loop watercooled system retro fitted into an old cockpit voice recorder that I was gifted (Something similar to this) with dimensions of around 180 * 120 * 320mm. I am going to lengthen it to arround 400mm vs the 320mm it is currently, allowing me to fit larger radiators and, in this case, it'd be perfect to fit one of these 400w LED drivers along the length of it as it is 334*53*22mm in dimensions and it'd fit nicely in my current plans.

Oh and to make matters harder I've decided to make this my first hardline watercooled build. That should be fun..

 

[Choidebu]

Please don't. Search this forum for '12v guide', we have some infos and options for you there.

In short,
1> ripple needs to be <120mVp-p
2> poor regulation. led drivers are mostly constant current (to some degree), constant voltage is not even on the requirement.
3> very cheap components and design, leading short life and very low efficiency, we're talking 60% area here.

If a 400W brick is 30usd while a proper medical grade 200W supply is 50usd, do think twice...

 

[Max Harrison]

Please don't. Search this forum for '12v guide', we have some infos and options for you there.

In short,
1> ripple needs to be <120mVp-p
2> poor regulation. led drivers are mostly constant current (to some degree), constant voltage is not even on the requirement.
3> very cheap components and design, leading short life and very low efficiency, we're talking 60% area here.

If a 400W brick is 30usd while a proper medical grade 200W supply is 50usd, do think twice...

This was my worry, I'm still going to order one of those as I need a 12v psu for the LED's I have in my pool, and I will check it out while I'm at it I might as well, but won't be plugging it into anything unless it's somehow the holy grail ahaha

 

[Ajjj]

Hello everyone,

i know this is an old thread, but i am wondering how do you see this topic after nearly 5y.

I am building a NAS as project and i need to power a small SBC (zimablade 7700) and up to 4x 3,5" hdd.

My idea is to use a cheap SMPS from china, coupled with pico PSU as the original poster, but my power requirements are much, much lower. The SBC takes MAX 36w (in my configuration will never reach it) and the HDDs should take max 40w at start up then significantly lower.

I was thinking about a 100w SMPS and a 160w pico PSU (i do not seem to find smaller ones)

compared to linear transformes, SMPS should have a much lower volt ripple. Don't they?

the parameters of my projects are:

- It has to fit within the brocken DROBO 5C i chose as housing, so i do not have a ton of space available.
- It has to use as fewer component as possible
- PSU should be internal and not a power-brick
- PSU should work in US (110V) and in Europe (220V). I am an expact in US now, but i may go back to EU sooner than later
- it has to be cheap

(disclaimer: i am a chemistry graduate with a knack for computers, i am not an expert in the field and this is a project i am making for fun and to learn something along the way).

 

[Gilles3000]

Hello everyone,

i know this is an old thread, but i am wondering how do you see this topic after nearly 5y.

I am building a NAS as project and i need to power a small SBC (zimablade 7700) and up to 4x 3,5" hdd.

My idea is to use a cheap SMPS from china, coupled with pico PSU as the original poster, but my power requirements are much, much lower. The SBC takes MAX 36w (in my configuration will never reach it) and the HDDs should take max 40w at start up then significantly lower.

I was thinking about a 100w SMPS and a 160w pico PSU (i do not seem to find smaller ones)

compared to linear transformes, SMPS should have a much lower volt ripple. Don't they?

the parameters of my projects are:

- It has to fit within the brocken DROBO 5C i chose as housing, so i do not have a ton of space available.
- It has to use as fewer component as possible
- PSU should be internal and not a power-brick
- PSU should work in US (110V) and in Europe (220V). I am an expact in US now, but i may go back to EU sooner than later
- it has to be cheap

(disclaimer: i am a chemistry graduate with a knack for computers, i am not an expert in the field and this is a project i am making for fun and to learn something along the way).

Cheap chinese SMPS' were bad 5y ago and they still are today. For a NAS I'd assume you'd want something reliable?

I'd get something proper like a Mean Well RPS-120 they're rated for 84W/120W with passive/active cooling respectively, and available in a range of voltages depending on what pico psu you choose.

At around $30 they're not even expensive and available from trusted retailers like digikey and mouser in the usa.

 

[Arboreal]

Also, take a look at the 12V power supply thread here on SFFN.

Apparently Mean well done a new LOP range of 12V power supplies like the RPS mentioned.

They're mentioned here:

Power Supply - A Guide to 12V PSU

Hello homeduck and welcome to the forum, I have bought a second hand silverstone ml09b case which hosts Sfx PSU, Hw is made up an asrock j4105 mb, 2 ssd and a slim sata drive. How can I understand which Meanwell psu fits my purpose? I mean if 100W or 150W or more. With such hardware, PSU...

smallformfactor.net

 

[Ajjj]

Cheap chinese SMPS' were bad 5y ago and they still are today. For a NAS I'd assume you'd want something reliable?

I'd get something proper like a Mean Well RPS-120 they're rated for 84W/120W with passive/active cooling respectively, and available in a range of voltages depending on what pico psu you choose.

At around $30 they're not even expensive and available from trusted retailers like digikey and mouser in the usa.

Thank you!

The RSP-120 seems a great solution, and it is even available used on ebay; but it is too big. it will take most of the surface area below the HDDs slides and i would not know where to put the SBC. As form factor, the "ultra-thin" LED drivers are just perfect.

i understand the point of having a reliable PSU, though, my thinking was: "if I use a 100w psu and i barely draw 30w from it continuously, it should last a long time even if it is not the best in quality". But maybe it is a faulty way of thinking, i dunno.

my point in the need of being cheap, is connected to the purpose of the project as well . For this endevour to make sense in my mind, it as to cost less than comparable and ready to use solutions like the DXP2800 from Ugreen. I have budget space for the time being, so i will look into the Mean-well solutions.

 

[Ajjj]

Also, take a look at the 12V power supply thread here on SFFN.

Apparently Mean well done a new LOP range of 12V power supplies like the RPS mentioned.

They're mentioned here:

Power Supply - A Guide to 12V PSU

Hello homeduck and welcome to the forum, I have bought a second hand silverstone ml09b case which hosts Sfx PSU, Hw is made up an asrock j4105 mb, 2 ssd and a slim sata drive. How can I understand which Meanwell psu fits my purpose? I mean if 100W or 150W or more. With such hardware, PSU...

smallformfactor.net

thank you!

the LOP series looks great, but it also looks kinda overkill for my application. the EPS-120-12 on the other hand, seems more in line with what i need.
LOP vs EPS
comparing each other i do not see big differences, beside the power output ofc. Any reason why the EPS would be a bad choice?