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Pixels flicker when being powered from different power supplies


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I have built a pixel matrix and have been running it on 3 amps (5v) for a while. They would be yellow half way through the third string, instead of white. I connected a second supply (A camera charger), 1.5a, to the third & second strings's + and second -. Everything was working really well and they were all looking really white and bright. Then, only when the screen was all white, the third string (Strange because the power should have been going everywhere) was flickering. The flicker would come about 2/3rds of the way into a fade or if it was completely white.


I am going to get a 30a power supply soon, but that will be connected to my pixlite. These run on a small DMX controller that connects to the Pixlite's  RS485 DMX output, and runs on a different power supply(s).


Also, I know that 5v doesn't carry very well. The first transformer is a 12v one that will go in a box and then 12v will go to the back of the matrix, where there is a 12v to 5a step-down.

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Sounds like not enough power. How many pixels are on the 3a PS. Last year I ran 1000 pixels from a 60a 5v supply. I had ~16.67 amps to each string of 50. That's averaged. I doubt there was that much power to each string but you need a bit of headroom too, typically, 20%.


The rule of thumb with 5v is about 50 pixels before power injection is needed. Try more power and see if that clears up the problem. 

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Would you get an identical power supply or does it not matter as long as it is 5v? I found a cheaper one to the first one I purchased.

Also, would having wires back to the same power supply  to different strings help distribute the power?

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I don't think what type, you just have to have the voltage right.

Last year I had a 60 amp from Holiday Coro and it ran about 4 different elements. In my picture below, the spider burst, circles, burst in the middle, fan all were ran from that single power supply. The burst, circles and fan had power injection in 5 different areas. The spider burst had 3. The circles were injected every two circles.

You will need to fuse the v+ wires from the PS, just as a precaution. It's also good practice to get into.

Edited by Ron Boyd
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Oh OK. My pixels should easily run off the 40 amp that is on its way.  :)

In the UK we have fuses in the plugs. Wouldn't that be enough or would putting individual fuses on each run to the lights be better?


Also, if I have long runs, the power really drops. The pixels are at full brightness until the power gets to below 4.5volts. Can I have two seperate power supplies powering the same item (So I can have one really close and the other connected through the pixlite4?


I understand pixels, but powering them is quite confusing.  :wacko:

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