Which PSU to use for display?

BigRedNole

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I am planning on using 12V, but open to 5V as well if someone can sway that decision. I am generally looking into which power supplies are better to use (i.e. which brands/suppliers)?

Also, I read on an old thread that someone has used HP server power supplies for a mega tree. If anyone has done that, I would want to read a lot more on that. I have access to those power supplies for free.
 

ezellner

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MeanWell power supplies appear to have a solid following due to their reliability. They cost slightly more but are worth it based on my experience using both MeanWell and cheaper supplies. Re: 12 V vs. 5 V, 12 V requires fewer power injection points (roughly one every 100 vs. one every 50 for 5 V set-ups). The trade off is more power consumption with 12 V (about 2.4 times as much) and more power supplies (2.4 times as many). This assumes the power supplies frequently used that are around 300-350 watts for both 5 V and 12 V systems. That's if you design to be safe and assume 100% intensity. If you cheat and set-up your system to run at lower intensities, you can get away with fewer. In that case, be prepared if you accidentally run 100% intensity and all kinds of bad things happen.
 

Derf

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If you have access to server power supplies go for it. The main reason people use meanwells / raywells is the price. Server PSU's have quite a lot of current capability and can easily be modified to work in this lighting hobby. You would just have to take into account you won't be able to use Cable glands if you want a server PSU in an external enclosure as the C13 Fitting into any gland that will allow a water tight seal.

The Pros of Server PSU's:
  • High 12V Rail Output (Normally HP Server PSU's)
  • No Messing about 240/120v Mains as it is a standard connector
  • its free for you
  • If you use a hot swap adaptor you can easily change a PSU if it fails
Cons:
  • Harder to put in outdoor enclosure
  • fans normally run 24/7 on the supply
  • thicker gauge wire normally required as the current is higher than a standard meanwell PSU
  • if not using a hot swap adaptor you will solder cable to the output pins of the power supply which doesn't normally look to great and having the 12v rail exposed

I use them quite a lot for bitcoin mining. we were not allowed exposed 12v rails in the data centres so we use to buy HP Server PSU adaptors. There are a lot of cool things you could adapt to this hobby by simply putting Server Power supply and the word bitcoin.

https://www.ebay.com.au/itm/Gigampz-Adapter-Board-for-Bitcoin-Miner-Power-Supply-HP-DSP-Antminer-ASICMiner/263081664226?hash=item3d40e39ee2:g:K0oAAOSwq7JUBi62:rk:1:pf:0
 

scamper

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5v vs 12v... I have both, pretty much because of price of pixels. 5v ones are cheaper. I use 12v for strips. The disadvantage (if you can call it that) is you need to be careful you don't accidentally put 12v into a 5v string. I did once... ONCE...
Now all of my props are run with data only coming from the control boards and powered separately from the appropriate supply.
I have only ever used cheap supplies purchased off ebay and always have a spare on hand just in case of failure. To date this is my 5th year and have no had a single failure save some noisy fans. At last count I have 12 supplies running and 2 spare in the shed.
I did use a server power supply just for testing, but as I didn't have a ready supply of them never attempted to work with them. What Derf was saying about cabling from them can always be worked around, for example you could put a bus bar in the box with the supply and then run several pigtails out through cable glands.
It all really comes down to what you have access to, what funds you have and how pedantic you want to be with your display setup.
 

Dez

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Yes i have the same newbie question. You should never connect the positive of 2 power supplies together. So how is it different if connect 1 power supply to 1 end of a pixel string, then connect the 2nd power supply to the other end of the same pixel string?? Let’s assume the pixel string is 200 pixels in length.

Are they not still connected via the positive terminals? Please pardon my ignorance with electronics
 

MrX

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Simple answer, it isn't any different and you should not do it. Separate your power needs into zones and make sure there are no positives from two different supplies connected. In my large matrix I have 4 power zones with runs of 400 pixels with injection every 100 and at each end. This means I can run multiple PSUs just for this if needed.

There is no issue powering one string from one controller output off two different PSUs just just make sure the data runs in one logical line as per normal and connect the grounds but make sure the positives don't connect. There are some exceptions with some PSUs which can be run in parallel and some ways to hack power supplies so that it will work but probably not recommended unless you know what you are doing.
 

scamper

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Connecting the positive of 2 power supplies is really only a no no because if the voltage is different they try and compensate, but if you have a string of lights you have a separation and if one has a slightly higher voltage, it will just supply power to more lights.
You do need the negatives connected though, as there needs to be a reference to ground. If for example 1 supply is at 12.2v and one is at 12.5 volts, the positive may not be higher or lower, but the negatives are. So then in reference to the data line, which is very low, there may be next to no data getting through.
 

Dez

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Now you both have confused me. If you have a string of pixels which is 200 pixels long, do you connect the positive from each of the pixels to the positive of 2different power supplies or do you always make sure to use 1 power supply that can handle the load?
 

tooms

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I ran 6 of these water proof supplies from Ray this season, scaled up from 3 to 6 last year and have not had any problems -

https://www.aliexpress.com/store/product/12V-300W-waterproof-switch-mode-Power-Supply-IP67-rated-AC170-240V-AC90-130V-input-DC12V-output/701799_32475103050.html?spm=2114.12010612.8148356.5.2710668bZ7iqma

The bonus for me with these was I installed them outside enclosure's and not have to worry about the heat generated from the PSU inside an enclosure, so now running much smaller enclosures, big enough to house a falcon distro board and falcon diff receiver board.

I ran 3 of them on my tin roof simply laying them on the roof and anchored to the roof with a tek-screw, I was cautious to not turn them on while the sun was out but I still think they would have been pretty hot in the evenings, I live in Kalgoorlie and our temps during December floated anywhere from 31 to 42 degree's most days and these things were completely exposed, we also copped a few good summer storms that should have been classed as cyclones with hail stones the size of cricket balls and they still kept on running.

I'll be getting another 4 this year to convert the 2 remaining enclosures I have from internal to external power supplies.
 

Dez

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I ran 6 of these water proof supplies from Ray this season, scaled up from 3 to 6 last year and have not had any problems -

https://www.aliexpress.com/store/product/12V-300W-waterproof-switch-mode-Power-Supply-IP67-rated-AC170-240V-AC90-130V-input-DC12V-output/701799_32475103050.html?spm=2114.12010612.8148356.5.2710668bZ7iqma

The bonus for me with these was I installed them outside enclosure's and not have to worry about the heat generated from the PSU inside an enclosure, so now running much smaller enclosures, big enough to house a falcon distro board and falcon diff receiver board.

I ran 3 of them on my tin roof simply laying them on the roof and anchored to the roof with a tek-screw, I was cautious to not turn them on while the sun was out but I still think they would have been pretty hot in the evenings, I live in Kalgoorlie and our temps during December floated anywhere from 31 to 42 degree's most days and these things were completely exposed, we also copped a few good summer storms that should have been classed as cyclones with hail stones the size of cricket balls and they still kept on running.

I'll be getting another 4 this year to convert the 2 remaining enclosures I have from internal to external power supplies.
What made you choose these power supplies? Was it simply so you could mount them outside?
 

tooms

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What made you choose these power supplies? Was it simply so you could mount them outside?
Yep, outside and less cost with enclosures as I wanted more on my roof, I even ran one this year in a garden bed just thrown on the ground
 

scamper

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Now you both have confused me. If you have a string of pixels which is 200 pixels long, do you connect the positive from each of the pixels to the positive of 2different power supplies or do you always make sure to use 1 power supply that can handle the load?
As best practice always try to keep the power supplies dedicated to props. If you must have more than 1 supply for a prop, say a matrix or megatree that has too many pixels for a single supply to handle, then you can do 1 of two things, make sure the power supplies are compatible, so they are the same. and the you can connect 2 different supplies to the same prop, just do it from different ends of the prop. Or you can do what a lot of people do and cut the power at the injection point so the 2 +v's never meet.
In practice, you will be pushing to have a prop that requires more than 1 supply to run, so this should really never be an issue.
 

BigRedNole

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Thank you for all the information. I thought I would be able to use PSUs in the scrap bins, but that is not the case. They are not really scraps. They are sent for service and refurbed for field support. So, I will wind up purchasing. My initial setup is not going to be huge for this year and probably only ramp up 1 thing per year following. Rough estimate at the moment is just under 1,100 pixels (eaves, windows outline, and garage door outlines). I will do some mapping and calculations on the number of PSUs and make sure I have 2 spares on hand. If they aren't needed, they can move to the next year's new prop and purchase additional spares then too.
 

BigRedNole

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Thanks for the video. Very informative and a lot of options instead of the more expensive T-connectors.
 
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