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AssuredElectrical, Master Electrician
Category: Electrical
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Experience:  Contractor-42+ Years in the ElectricalTrade
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How to power circuit boards

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Hi, I have a somewhat unusual situation. I need to power a large number(200ish) of circuit boards. The input is two +12v and two grounds(A pheonix connector), but I only need to provide one +12v and one ground. Constant draw, ~120 watts.


So far my solution is this:

1. Take a computer power supply with several PCI-E outputs. PCI-E is +12v and a ground, rated up to 150w, using 5 grounds and 3 +12v wires.

2. Cut off the ends of all 8 PCI-E cords, strip them. Now they can go directly into the pheonix connector, but with 8 stranded wires this is a pain(x200 times).

3. Join the 8 wires together with 2 wire nuts, one for +12v and one for ground. Out of that comes a 14ga solid copper wire(So I don't have to twist the strands).

4. That goes directly into the pheonix connector.


So this process works. It also provides stable +12v, and can take any range of input(100-240v), which is nice.


This is really inefficient though- I have to strip 12 wires per and use two wire nuts. One PSU is like $200, powers 7-8 of these.


What are my other options to provide stable +12v power to these devices? Is there maybe an adapter I could buy or find that would take a computer PSU's +12v into a pheonix connector? Is there some way to make this more efficient than what I've already got? A better power supply/converter perhaps?


If it matters my inputs will be 120/208 three-phase.


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Customer: replied 4 years ago.

Hi Michelle,

I have not yet found an answer, and would still like assistance.

If someone can't help me better solve the main problem, but can provide me some advice on what sounds unsafe/likely to fail, or other relevant opinions from their experience on what I'm doing, that would be worth something to me as well(Maybe $15?), although not as much as the real question.


Thank you, XXXXX XXXXX continue to look for a professional to assist you. Please let me know if I can be of any further assistance while you wait.



Welcome. My name is XXXXX XXXXX would be glad to assist.

Let me get some more information to understand the situation correctly.

You want to power 200 circuit boards?

Each board uses only 2 wires , +12v and -12v?

All boards have their own connector for plug in to power the board, so just need to wire the plugs?

AC or DC output on the power supply?

Does each board consume 120 watts? Or is this a total of some or all?

You want to keep connections down as minimal as possible?


Customer: replied 4 years ago.

Yes, I want to power 200 circuit boards.

Each board only needs 2 wires, +12v and ground. (No -v). It has two additional +12v / ground inputs that are optional but not required(See photo below- 4 phoenix inputs coming in total). Each board draws 120 watts individually(Yes, this is a lot of power, something I am tackling separately.).

Each board has a separate input. It looks like this, complete with the phoenix connector:

The power supply currently does DC output, AC input, but that is a piece that (?maybe?) can be changed.

I would like to keep the work required to wire up each board, and the total cost of the parts involved(primarily PSU's but also wiring) to a minimum, while making sure that the setup is as safe and stable as reasonable(No chance of the wires melting later due to the high amperage, etc).

Ok, thanks so much for the details.

I have a setup in mind now, so let me put it together and see if it is a feasible solution.


But let me be sure beforehand.

Never seen a circuit board consume 120 watts, that is a huge number, especially at 12 volts.

More than a refrigerator.


Wire sizes are going to be enormous for distribution from a power supply trying to provide multiple boards from one unit.


That is the board requirements to power up, is that correct?

The power requirements for the total 200 is certainly something that needs attention and research

As for the circuit boards, you stated that the power supply you have outputs DC, does that mean that the boards require DC or can they operate 12 volt AC? (just for information on looking for power supplies at the moment, it wont affect the setup and wiring either way)


Customer: replied 4 years ago.

Yes, it is a lot of power, and produce a lot of heat(separate problem). These are doing computational work.

So the power supplies I've been working from take 100-240v AC coming in, 1000w maximum. I use them to power 7 of these each. Each one is powered by one PCI-E output(8 wires).


The output must be 12v DC.

Does that help? What did you have in mind?

Ok, understand.
I had the below in mind. Helps to keep it uniform and identical for parts etc.

I used a 750 watt supply with single output wires to make it easy for distribution.
That way, you power to one distribution Buss and supply a group of boards at the same time.

The higher the wattage, the heavier wire is needed depending on the distance from the power supply.

I can give you the locations to purchase the material used in the diagram.
Look it over, let me know your thoughts.



Click on the image, then click the "Raw Image" for an exploded view

Customer: replied 4 years ago.

Thanks for the reply. That does look better than what I had in mind, although not a complete game changer for my process.

Do you have links to where I could buy those things(the bus and the power supply?)

Sure, not a problem .
There are other busses available at some of the locations, so it is not just the one I posted, although I thought it to be the best to use in the application.





I do not see any way of cutting time with the board wiring themselves. Takes 2 wires and about it.
Power supplies with a single capable output seems to be the time saver, just wire to the buss and over with as opposed to multiple connections and splitting off wires.

Tried running other scenarios, and that one I posted seemed the easiest and most practical based on experience in building control panels and automated systems for industry.

Opinion of course, we all have our personal preferences
I like the use of Marine distribution equipment because it is a clean install and the components are rated high and fit many low voltage applications.
They have so much more to offer, if you navigate the sites.

Let me know if any other information is needed.
AssuredElectrical, Master Electrician
Category: Electrical
Satisfied Customers: 4241
Experience: Contractor-42+ Years in the ElectricalTrade
AssuredElectrical and other Electrical Specialists are ready to help you
Customer: replied 4 years ago.

Hm, so that is a good solution, maybe a better solution than what I have. It rounds out to ~210 per 7 including shipping as opposed to ~$246 per 7 for the other way(labor included). Going with a higher amperage requires an even more ridiculously thick wire.

I'm not sure if it would be more stable. How reliable are those PSU's, do you have any experience with them? Could they run reliably in a relatively hot setting(~95 degrees F) for years on end?

I'm also not sure how to wire in the really really thick #4 wire. Will it even wire properly to the se-1000-12 version? And fit under the busbar screw?

I think unfortunately I'm going to have to stick with my current method for this batch, but I'll experiment with the busbar and PSU, and perhaps switch to this method for the next batch. Thanks for the help, and if you could respond to the above questions too that'd be great.

The PSU's should be able to operate in that environment as they are built for -40 ~ +85C, 10 ~ 95% RH

That is double your ambient.

I have only used a few of these units from that company. So, I cannot speak for their longevity, but they do come with 3 years warranty so the company does feel good on them and stand by their product.

The buss bars have been used many times and are a great distribution asset and easily installed.

The #4 wire will fit, you use a ring terminal lug with the correct hole diameter. It crimps on the end of the wire and then fits under the screw tightly. Should be no issue on connections.

I will look further and see if there are any other alternatives that I may not have looked at it in the past. Always nice to keep an open mind.

Will let you know if I find an alternative.

Thanks for the rating, it is appreciate and glad to work with you on the situation.

Customer: replied 4 years ago.

Thanks so much for the details. That will help me when I'm experimenting with this solution.

And thanks for considering futher options. If you come up with something significantly more efficient, I would gladly tip for the information. I have considered trying to power them 1 per PSU (12v 10A), but that never seemed to be more efficient when I worked out the numbers.

You are welcome and will contact if I find another solution.
Customer: replied 4 years ago.

Hm, I got an email asking me to rate your response so that the payment goes through, but I've already rated, so it is warning me that it would charge me twice. Did the first rating go through and give you credit?

Honestly, I do not know why the system sent that to you.

All is fine, your rating was received and credit to me as well.

Guess sometimes the system doesn't understand that once it is rated, further answers do not require any rating.

Just ignore, all is well and thanks again

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