flickering pixels

DeeJai

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DannyP said:
No I am using 14/020 cable and 3.3mm heavy duty low voltage garden lighting for the power injection. I am thinking it could be the speed setting in the P12R but I have it at 3200 which I thought was pretty standard.
3200 is pretty high, i run mine at 2400.. try out lower levels and see how you go.
 

Benslights

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my 2811's i run from 2400 - 3400. it all depends on the length of the cable. for short cables i have it set at 3400 and for a 6.5 m length i have it at 2400
 

David_AVD

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In theory, 3200 is exactly the speed that 2811 pixels require. Not sure why the variation in speed works or if it's really required.
 

dpavisic

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Ok I think I have narrowed it down. I don't think I understand how to hook up the power supply's using 3 PSUs. In the attached picture (sorry but I couldn't make it clearer), I have -

4 x 100 pixel Technicolour strings (in fact I have 11 but that complicates the picture).
Each string is treated as separate universes and is connected to its own output on the P12r. The P12 R is supplying + N and data. One side of the P12 R is getting power from PS1 and the other side is getting power from PS2. I have the Negatives connected between PS1 and PS2.

At the top of the matrix I have another power supply (PS3) and I am using this to inject just power at the top of each string (shown as a red dot on the diagram). I am injecting both + and Negative into each string. You will see that most strings are injected from 1 power cable that runs from the PS3 and then splits to supply 2 strings. This is for both the + and negative. I then have the Negative from PS3 running back to PS1 and 2 so that all the Negatives are connected.

When I turn on the matrix, some lights flicker, some don't turn on at all and some randomly light up in multiple colours. Even when I started disconnecting the lights from the P12R, they still keep lighting up until I have disconnected the last output. I couldn't work out how the lights still lite up when they were unplugged from the P12R, but Im now thinking its forming a circuit by the way I have connected power.

Reading through the 101 manual, I cant find this exact setup but Fast Eddy does say not to connect the + between power supplies, but I'm thinking that this is exactly what I have done even though PS1 and PS2 are going through the P12R. Am I right and if so can someone tell me where I have gone wrong and how to fix it?
 

drakky

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interestingly I have placed a pixel right on one of the P12 controller outputs to run the boyosco holdman 42" star (146 nodes) power injected at back end , so power and signal on the front and power on the back end told the the P12 there's a null pixel and the thing runs fine over a 10 metre cable, without the pixel in there it flickers and carries on, does this mean that the P12's signal output isn't that good?
 
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AAH

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interestingly I have placed a pixel right on one of the P12 controller outputs to run the boyosco holdman 42" star (146 nodes) power injected at back end , so power and signal on the front and power on the back end told the the P12 there's a null pixel and the thing runs fine over a 10 metre cable, without the pixel in there it flickers and carries on, does this mean that the P12's signal output isn't that good?
If the J1 Sys P12 is the same as the P2 then it will have 300 ohm resistors in series with the line drivers on the outputs. Best practice and the recommended resistor on pixel data sheets is normally something like 33 ohms. Having the higher resistance means the driving distance is dramatically reduced but the line driver is better protected if it happens to get shorted. Placing a null pixel close to the P12 uses the 33 ohm (or similar) resistor that is built into the pixels.
 

drakky

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If the J1 Sys P12 is the same as the P2 then it will have 300 ohm resistors in series with the line drivers on the outputs. Best practice and the recommended resistor on pixel data sheets is normally something like 33 ohms. Having the higher resistance means the driving distance is dramatically reduced but the line driver is better protected if it happens to get shorted. Placing a null pixel close to the P12 uses the 33 ohm (or similar) resistor that is built into the pixels.
ok well I guess then I'll just put a null pixel on every output , thanks
 

AAH

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ok well I guess then I'll just put a null pixel on every output , thanks
It's probably easy to change to a 33 ohm output of you're a competent solderer. I dropped a 33R on top of the 300R's on my P2's. I've never seen a P12 in the flesh to see how hard it is to do on 1 of them.
 

drakky

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It's probably easy to change to a 33 ohm output of you're a competent solderer. I dropped a 33R on top of the 300R's on my P2's. I've never seen a P12 in the flesh to see how hard it is to do on 1 of them.
I'm guessing they are surface mount resistors as there's no normal resistors on the boards,so I'll just throw a normal pixel on each output, that will be the only thing the board will power as I'll run all power separately should be all good I think
 

drakky

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forget null pixels the line drivers work 10 times better and you don't have to program anything
 
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