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Production ONE2 DISTRO 400 - A 12V Power distribution board

InfernoZeus

SFF Lingo Aficionado
May 23, 2017
98
53
1. Compatibility with pico psu. The distribution board will use a load sensing circuit to turn on a load switch (or relay) to distribute 12V power to PCIE outs. However 12V rail will still be on on the input side. Positive is less wires.

Yes, yes, YES! I was thinking about exactly this yesterday. It seems like such an obvious answer for adding a power hungry GPU to the simplicity of the Direct-plug ATX solutions.
 

QinX

Master of Cramming
kees
Mar 2, 2015
541
374
The transistor used on my load switch and riser is a BTS555 rated for 165A : shouldn't be an issue !

Please keep heat dissipation in mind.
That it is rated for 165 does not mean that that is without any heat sinking/cooling.

Some napkin math:
Amperage:
400W/12V=33,3A

Voltage drop across Load Switch
33,3A*0,0025Ohm=0,083V

Power Dissipation in Load Switch
0,083V*33,3A = 2,78W

Now your Load Switch is soldered to the PCB so it's not in free air, but I take it as a guide in this case
From the Datasheet:
junction - ambient (free air): 30 K/W
For every 1 Watt of dissipated heat the RthJA goes up by 30
2,78*30= 83,4K, so at ambient 25C inside a computer case the load switch would be 108,4C

With proper heat sinking you'll not have any issue I think. but keep in mind that just a rating of 165A isn't the only thing you need to take into account.

PS: Not meant to be degrading in any way, just trying to inform you.
 
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Thehack

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Mar 6, 2016
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Yes, yes, YES! I was thinking about exactly this yesterday. It seems like such an obvious answer for adding a power hungry GPU to the simplicity of the Direct-plug ATX solutions.

Yes, we just need enough people on board. The other issue is since a small run item drives up costs and prototype.


Please keep heat dissipation in mind.
That it is rated for 165 does not mean that that is without any heat sinking/cooling.

Some napkin math:
Amperage:
400W/12V=33,3A

Voltage drop across Load Switch
33,3A*0,0025Ohm=0,083V

Power Dissipation in Load Switch
0,083V*33,3A = 2,78W

Now your Load Switch is soldered to the PCB so it's not in free air, but I take it as a guide in this case
From the Datasheet:
junction - ambient (free air): 30 K/W
For every 1 Watt of dissipated heat the RthJA goes up by 30
2,78*30= 83,4K, so at ambient 25C inside a computer case the load switch would be 108,4C

With proper heat sinking you'll not have any issue I think. but keep in mind that just a rating of 165A isn't the only thing you need to take into account.

PS: Not meant to be degrading in any way, just trying to inform you.

Indeed. Usually fat mosfets are tied to heatsinks or boardsink(?) Either way, we're just looking at 25A nominal for the first design. Do you happen to be an electrical engineer?
 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
952
1,124
@Thehack : the most power it's rated for, the better it is !

What side of the circuit would have to be beefier to cope with a greater current ?
The part of the circuit cleaning the input signal ?

@QinX : no problem, your explanations are more than welcome :)
I was just saying that the load switch is rated for 165A, which gives us lots of margin, as we aim at 30/35A max.
 

QinX

Master of Cramming
kees
Mar 2, 2015
541
374
Indeed. Usually fat mosfets are tied to heatsinks or boardsink(?) Either way, we're just looking at 25A nominal for the first design. Do you happen to be an electrical engineer?

I'm not capable of any circuit design like HDPlex or G-unique is making.
I can design a PCIe riser and such and simple circuitry but not anything that involves a lot actual knowledge like how certain inductors and switching frequencies need to be tuned to each other.

no problem, your explanations are more than welcome :)
I was just saying that the load switch is rated for 165A, which gives us lots of margin, as we aim at 30/35A max.

Great that I can be of assistance, just keep in mind that 30/35A already needs some proper heatsinking, either via a PCB with vias or an actual heatsink.
 

Sashby

Average Stuffer
Nov 13, 2017
71
105
Omg god I hope this becomes feasible!
I do have one small suggestion if possible. Could the pcb board be spilt in two? Benefits: segregate heat per board and distribute the board size around the computer case in two halves. Regardless I'm very excited for this and the KMPKT Merge.
 
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Thehack

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Omg god I hope this becomes feasible!
I do have one small suggestion if possible. Could the pcb board be spilt in two? Benefits: segregate heat per board and distribute the board size around the computer case in two halves. Regardless I'm very excited for this and the KMPKT Merge.

1. If heat management is an issue, it would be best resolved by heatsinks, which doesn't necessitate separate boards.

2. I would say, I think the board will be small enough to where it's not a big deal of you requiring to separate the board for sizing. Otherwise, there's nothing saying you can't use 2 boards.

For this to make it, we need a several people interested in the first run. I'm willing to front a good portion of the design costs.

Edit: I think doing a 400W design first is the most feasible option. If this gains traction, possible 250W and 600W version.
 
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Link1712

Chassis Packer
May 29, 2018
17
8
Well we already have a 600W version. If anyone is interested in one of those two samples i mentioned earlier, just DM me.
 
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Thehack

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Well we already have a 600W version. If anyone is interested in one of those two samples i mentioned earlier, just DM me.

I'm looking more for a 12V version. Simpler, more compact. It's really the future.

The first post has been updated with better diagrams and stuff.
 

Kmpkt

Innovation through Miniaturization
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Feb 1, 2016
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Just checking out the details of this for the first time. If I'm not mistaken, isn't this just a 12V version of my Dynamo 360? Also I'm not claiming IP or anything, I actually think it's a very elegant solution and hope you can bring it to fruition : )
 

Thehack

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Just checking out the details of this for the first time. If I'm not mistaken, isn't this just a 12V version of my Dynamo 360? Also I'm not claiming IP or anything, I actually think it's a very elegant solution and hope you can bring it to fruition : )

Yes. If anything, the Dynamo 360 provide additional load balancing features that this will not have. This is a less featured version.

This is niche of niche and I hope it will allow us to further miniaturize our builds. If you recall, we did have a conversation where we discussed your decision to go with 19V. I'm really just trying to bring a project that I've been thinking about for a long time but haven't had the balls to pursue.

I hope it solves how difficult it is to get a G-Unique running, as this will be compatible with any PicoPSU style units.
 

aquelito

King of Cable Management
Piccolo PC
Feb 16, 2016
952
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@Kmpkt : yes, this is a very welcome initiative from @Thehack, to formalize and gather in one single board the various experiments and solutions some of us came up with within the last past year.
Being either Thehack own experiments, or my 12V load switch for instance.
 

Thehack

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12V system almost run in large current so a couple or more of V-in terminal is need.

I have 2 sets (4 total) of screw terminals. There are 400W psu that use only one set of screw terminals yet they provide 33A output. These are industrial rated units so I think my two sets are safe.
 

Kmpkt

Innovation through Miniaturization
KMPKT
Feb 1, 2016
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It was where the board designer put them. I am planning to revise the board for version 2.0, so if you have any suggestions I'm all ears.
 

Thehack

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It was where the board designer put them. I am planning to revise the board for version 2.0, so if you have any suggestions I'm all ears.

I'm thinking about adding mounting points of 32x32 for compatibility with 40mm fan mounts. My board would be about 50mm width.