Decrease Number of Power Supplies

L

Little_b

Member
I am curious what others are doing about the number of power supplies everyone uses with how many pixels are in your display. I have a matrix that is just under 8000 12v pixels. It requires 13 power supplies and 3 20amp breaker circuits to run it. I have other pixel props (mini trees, arches, snowflakes, etc.) and I've found I can only put about 4-5 power supplies on a single breaker. Is this normal? Now I understand if I used 5v pixels instead I could get double the total pixels per power supply, but some of my runs are long and the 12v seemed to be a better choice. Plus I like to use all the same type so I don't have to worry about mixing them up on accident.
I want to add another prop that could take up to 10K - 12K pixels. Some of the runs are fairly close to the Controller/power supplies, but others are about 20-30 feet away and power injection gets more difficult on this one, which is why I'm still thinking on using 12v pixels. Is there a way to power it all without having to line the lawn with 15-20 power supplies?
 
First thing I?d do is decrease brightness. There is very little difference between 50% and 100% to our eyes but power is directly proportional.

I would question your power supplies per pixels as well. I have a matrix with 4,600 pixels and run it off only four 12 volt power supplies.

Have you measured the amperage draw of your pixels?
 
To add to what StickyWicket said, for reference, I run all mine at 10% and still plenty bright from the road and less stress and need for more power supplies. 100% and I light up mine and several neighbors yards and windows....you know I just had to see what full on 100% would look like. :thup2:
 
If you run 5v you can reduce the number of power supplies, but also if run length is a problem, you can add a 5v power supply just to reduce the run length and still.be using less total than had you run 12v. And you're not loading the breaker with the full 300w on that additional power supply--you're just splitting the load up. It's just that I see people liking to pack all their PSU's up together into one enclosure and then route long wires. I find ways to spread my PSU's out. I measure some of my 5v run lengths in inches.
 
I totally agree that more PSUs isn't a bad thing. The easiest voltage to distribute without problems is 120V AC. Keep the PSUs small and as close as possible to the props. Most of my props have PSUs built right into them I use a lot of 75 and 150W power supplies.
 
Don't know how large a 8000 pixels matrix is, but at that level of investment and equipment failure risk, maybe a weather protected TV is an option?
 
Thanks everyone for your responses. I've always calculated power needs based on full white as a fail safe. I hardly ever use full white as I don't really like the "off-white" color it produces. But I figure if something went haywire and everything turned on, I'd be safe. To answer some of the questions here, I use to only have 8 power supplies on the matrix and 2- 16 channel controllers, but I was constantly having flickering issues due to the length from the controller to the pixels was too long. So I rewired it into 8 sections, and every 2 sections is powered by 3 power supplies and one controller. I have had hardly any issues since. My matrix is 63 rows high and 126 rows wide, making it about 16' x 32' on my roof, so sorry iflights, a TV screen won't work. 7938 pixels times .045A/pixel = 357Amps divided by 30A/supply = 12 power supplies.

So on my new project, if I plan to only run the pixels at 50%, can I essentially put twice as many pixels on a single power supply? In my example above, would it equate to only needing 6 power supplies?

I agree on keeping the power supplies close to the props, I don't mind that, and I have several around the yard. At what point or how many power supplies until you overload the AC circuit breaker? I'm guessing if you plug them all in at the same time the initial power surge will trip it, but if you do one at a time, what is the average number of power supplies on the line are folks seeing?
 
I would have to agree with jchuchla. We run 5volt pixels in 99% of our show this year. We are still on two breaker's though we are not sure of the draw yet. We also incorporated fuse's on all of our big pixel items to hopefully prevent bad things from happening. About 70% of our props have independent power supply's. We bought a lot off ebay of older Thin client PS's and have been using them. 4 amps per prop is enough for running our show at about 15% bright. Our mega tree is running 2 60 amp 5v PS's just fine. Merry Christmas.
 
If you plug your PSU's into that thing on amazon I pointed to and set your pixels to the test color you want (e.g. 100% white), that will tell you exactly the current draw you are putting on the breaker. I cannot sing this thing's praises enough.
 
What's wrong with doing the math, and maybe verifying it down the road with an ammeter or power usage meter? 357A * 12V = 4200 W,and adding the usual 20% margin results in 5100W. Assuming 100% power supply efficiency (which isn't reality, but...) divided by 120 = 42A of 120VAC. I would split that over 2 or 3 of you house circuits (i.e. circuit breakers) unless you have a circuit with higher than normal amperage. The other thing that would need verifying is that each pixel draws on 0.045A, which is less than what I'm used to seeing.

Also, 1pet2_9's recommended power-usage meter is apparently rated for only 15A, which might not be enough for this project.
 
P. Short said:
What's wrong with doing the math, and maybe verifying it down the road with an ammeter or power usage meter? 357A * 12V = 4200 W,and adding the usual 20% margin results in 5100W. Assuming 100% power supply efficiency (which isn't reality, but...) divided by 120 = 42A of 120VAC. I would split that over 2 or 3 of you house circuits (i.e. circuit breakers) unless you have a circuit with higher than normal amperage. The other thing that would need verifying is that each pixel draws on 0.045A, which is less than what I'm used to seeing.

Also, 1pet2_9's recommended power-usage meter is apparently rated for only 15A, which might not be enough for this project.
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It doesn't have to be that exact ammeter. The point is that these meters exist which you just plug in. The problem with the math is it's frequently wrong math. The meter tells you as it is. And you have the power supplies already, so why guess if you don't have to?
 
Clamp on meter works for me, I have a couple of them laying around here. Just haven't needed to use it yet this year. If we need more power we would just put in more outlets. 200 amp service with plenty of room! 220v Outdoor sub panel might be on the list before next year though. Can get bigger power supply's than.
 
I like the clamps too, but I don't trust their readings too much at low currents (and low voltage, to a lesser extent). There are multiple 220v PSU's I'm drooling over. One's waterproof, so don't need a box. The other's got a thin form factor, so I can fit it right in a PVC and wire right out through a T coupler. So simple.
 
I prefer the larger psus and 12v myself. 12v is much easier to distribute for me and I try to keep AC out of the front yard as much as possible. I have 6 Meanwell RSP3000-12 spread out across the display with another 30 or so RSP320's in less dense areas. I've got close to 7k pixels on one of the RSP3000-12's @30% intensity and it isn't even breaking a sweat. I too would recommend a DC clamp ammeter. Be careful when buying one because most are only AC
 
1pet2_9 said:
It doesn't have to be that exact ammeter. The point is that these meters exist which you just plug in. The problem with the math is it's frequently wrong math. The meter tells you as it is. And you have the power supplies already, so why guess if you don't have to?
Click to expand...

Math can always be checked by others, and definitely helps in not avoiding under- or over-provisioning.
 
P. Short said:
Math can always be checked by others, and definitely helps in not avoiding under- or over-provisioning.
Click to expand...

I'm on the fence whether it's a worthwhile discussion, but it's like if you're trying to cut a piece of wood to the same length as another. Why tape measure it when you can just lay it down side-by-side and draw a pencil mark? Math has its place, but no need to calculate the current of 12 power supplies with P=VI when it's Christmas and you've literally got 12 power supplies running pixels sitting right there.
 
LOL xGROMx 7 of our power supply's are not server but computer ATX power supplies! Reason we use the ATX is the protection they offer is amazing! If there is a short even a pixel shorts out the PS will not turn on, and if you over draw on them they will shut down. Our mega tree last year had shut down due to to much current draw, it was the first time that had happened and it was a pure programming issue IE our fault but regardless it protected our tree from other issues that could have came from that simple error. We run all 5 volt lights now because of that also one of the strings last year had a shorted pixel and the PS wouldn't turn on. I replaced the PS three times before putting the ohm meter on the strip, but we feel that might have saved us from a mishap as the light that had shorted was on our structure. Anything attached to the house is ran off an ATX power supply for that reason now! We also have been purchasing 7-40v DC to 5v DC 350 watt converters so that we might be able to use something like the HP1200 or go even 36 volt out in the yard for the yard props. We like having the power supplies on the props as of now because of the safty, all the AC in the yard is on GFCI's.
 
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