Power injection for ws2811?

[Quefol]

Hello I'm looking at building a 50x24 pixel matrix display with a e682 or pixlite controller. I have 12 300 led 60/m 100 pixel ws2811 strips. My question is do I need power injection at the end of each strip if I'm using 12v. Also what size of power supply will I need would two 350w or one 700w be sufficient

Thanks 

[Mr. P]

50 minutes ago, Quefol said:

Hello I'm looking at building a 50x24 pixel matrix display with a e682 or pixlite controller. I have 12 300 led 60/m 100 pixel ws2811 strips. My question is do I need power injection at the end of each strip if I'm using 12v. Also what size of power supply will I need would two 350w or one 700w be sufficient

Thanks 

Not sure if you will need power injection but those power supplies will not be big enough. You will need to confirm the specs on your strips but most 60leds/m strips are rated at 72w so that would be 864 watts plus the general rule is 20% overhead.

[k6ccc]

I'm assuming that you will have each 5 meter strip fed from a separate output on the pixel controller.  Further, assuming that you will have the first  50 pixels in one row of the matrix and then the second 50 pixels as the next row in an opposite direction (a zig-zag pattern).  The third row will start the second strip and be driven by the second output of the controller..  Assuming I got that right, as far as the pixels are concerned, you likely wound not need power injection, HOWEVER the controller can't handle 72 amps.  Here is what I would do if I were building that matrix.  I would be using a SanDevices E682, so I will make assumptions around that, and use that in my description.  I assume the Pixlite is at least similar.  I'm assuming using the common 350 watt power supplies (three of them).

At the zig-zag point at the midpoint of each strip, I would wire only the data and ground.  I would feed power and ground to the end of the strip from the second power source.  That way the E682 is powering only the first half of the strip and the power injection is powering the second half of each strip.  As for distribution of power, power supply #1 feeds the left side of the E682, and power supply #2 feeds the right side of the E682, and power supply #3 will only be used for power injection.  I would connect strips 1 - 8 to the first eight outputs of the E682 (clusters 1 & 2), and connect strips 9 - 12 to the third cluster of the E682.  Power supply #3 would have some sort of distribution with fuses to feed the power injection for the second half of the the first eight strips.  I would then use power supply #2 via some fuse distribution to power the second half of strips 9 - 12.  If you are not planning on doing anything with the forth cluster of outputs from the E682, you could use those four outputs for the power injection to strips 9 - 12 by sending only the power and ground connections from teh E682 outputs to the end of the strips.

Using this distribution concept, with the entire matrix full white each power supply is supplying 24 amps, and each output of the E682 is feeding three amps for a total of 24 amps per side of the board.  that keeps all the parts within their power limits.

If this did not all make sense, I can create a drawing.

 

[Quefol]

Thank k6ccc I will probably use your advice 

[Quefol]

Could you draw a diagram for me when you get a chance 

Thanks

Edited December 8, 2016 by Quefol
Update

[k6ccc]

1 hour ago, Quefol said:

Could you draw a diagram for me when you get a chance

Ask and ye shall receive.  I will fully acknowledge that this drawing shown here is too small to read well.  It's here only to give an idea what it looks like.  However, here is a link to a high resolution pdf file that you can blow up to your heart's content:

http://newburghlights.org/images/25x24_matrix_power.pdf

The forum software does not know what to do with a pdf file...  Here is the sample:

 

[Quefol]

Thanks

[k6ccc]

BTW, in the drawing, Blue is ground, Red is power, and Green is data.

 

[Quefol]

I figured so