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I'm tring to build a led display with 32 strips of ws2812b led strips with 60 leds each. That's a total amount of 1920 leds. How many power supplies should I buy? Given the max current of 50mA per leds, that's a 50mA x 60 x 32 = 96A. I'm going to buy to power supplies of 5V 60A (https://www.amazon.it/HAILI-Trasformatore-Adattatore-Alimentazione-Telecamere/dp/B07Y38SMQ3/). What should be the connection of the strips? Should I power every side of each strip? I made a schema:

enter image description here

Do you have any suggestions to connect all these cables with each other? (32 + 32 each side).

The Led strip I'm using is the 1m 60 IP30 + WS2812BECO Black PCB as pictured here: enter image description here

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  • \$\begingroup\$ The ws2812b is not a strip it's an individual RGB LED as far as I remember. You are asking someone to confirm that the cabling arrangement for a power supply with no data sheet connected to some unspecified strips of LEDs is OK. Your expectations may be too high. \$\endgroup\$
    – Andy aka
    Commented Mar 29, 2020 at 18:21
  • \$\begingroup\$ Do not draw a schematic in this case. Rather draw the actual wiring diagram showing how you plan to connect the LEDs. You will need two 60 A supplies. \$\endgroup\$
    – skvery
    Commented Mar 29, 2020 at 18:24
  • \$\begingroup\$ Your are right, the LEDs are connected as pictured in the red box. There are 60 leds on each strip. \$\endgroup\$ Commented Mar 29, 2020 at 18:38
  • \$\begingroup\$ How far apart will the strips be placed? 60 leds/m = 18 watt/meter that's 300 mW per LED+driver - 10 mA for each driver? Anyway: 18 W * 32 = 576 W (cooling?) - 115.2 A. \$\endgroup\$
    – greybeard
    Commented Jul 31, 2023 at 4:31

1 Answer 1

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The wiring of the power depends on the layout of the strips, if they are connected exactly like in the image, i would switch build a ring supply (powering both sides of the strips.

Please be aware of the following:

  • 5V, 96A is no joke in terms of security. If the wires touch, there will be a huge arc.
  • 5V 96A requires large wire (like 25mm2)
  • Each strip of 60 LED's requires 3.6A, check if the strips are made for this current
  • Check if its possible to drive 1920 led from one data pin. Shifting out data for 1920 led is around 76.8k bits of data
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    \$\begingroup\$ 5V, 96A is no joke in terms of security. If the wires touch, there will be a huge arc. --> Another solution would be buy 10 power supply that provide 5V 10A if it's more safe; Each strip of 60 LED's requires 3.6A, check if the strips are made for this current --> from the vendor, I can see that 60 leds/m = 18 watt/meter; Check if its possible to drive 1920 led from one data pin. Shifting out data for 1920 led is around 76.8k bits of data --> Raspberry Pi Zero W has 512MB of RAM, I'll check how much memory is available \$\endgroup\$ Commented Mar 29, 2020 at 19:22
  • \$\begingroup\$ @DiegoBraga how fast do you want/need to update the LEDs? It’s not a matter of memory (this is insignificant) but speed of the data link to the LEDs. \$\endgroup\$
    – jcaron
    Commented Mar 29, 2020 at 21:37
  • \$\begingroup\$ @jcaron I want it to be really fast. I checked yesterday and the free memory on the Raspberry Pi Zero was 44MB, so pretty much space for the shifting data. What I'm concern is the connection of the 2 power units in the diagram I've attached: should I connected each side of the strip for both positive and negative lines? or should I attach just the input side for the positive line? \$\endgroup\$ Commented Mar 30, 2020 at 7:29
  • \$\begingroup\$ @DiegoBraga the WS2812 take minimum 19.2us per LED per frame + 280us reset. For 1920 LEDs thats minimum 37144us per frame, leading to an absolute max frame rate of 26.9fps. if you can get the timing exactly right. Realistically, if your bit-banging on a pi, theres a good chance you want more marging on that, and I wouldn't want to rely on anything more than 20fps. \$\endgroup\$ Commented Mar 30 at 0:24
  • \$\begingroup\$ That also means you'll have a close to 40ms phase difference in update point from the top left to bottom right. This probably won't be a problem, but might cause interesting shutter effects if it it interacts with anything else. It might be worth considering a horizontal interleaved pattern as used by early CRTs. \$\endgroup\$ Commented Mar 30 at 0:27

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