Help needed in 1000 neopixel project

[leoneckert]

Hello!

I am building some signs and each uses between 700 and 1300 LEDs, the WS2812. I am facing some uncertainties and wanted to ask for your help.

I am powering them with two 5V/40A power supply units. from the first one I guide two cables into a breadboard, put a capacitor 1000uF in between + and - and from the I connect the first strip of lights and from there the cable goes back to the arduino mega and powers that one as well. (I will attach drawing and photo).

The data cable crosses a 480ohm resistor and goes into the first strip and continues its way through all attached strips in the sign.

Aprox every 2 meters I attach new power supply to the strip. So all sections share the same data circuit, yet are individually powered. I ditribute them over the two Power Supply Units, too as I figuered 1300x60 / 1000 = 78 amp needed.

Does that sound and look correct?

it seems like the cables before the capacitor, that come from the power supply get extremely hot, in the beginning they even melted the breadboard (i then changed them to slightly thicker ones). also the lights get very hot.

Can you please help/correct me?

Thanks a million!

[adafruit_support_mike]

If you're running 40-70A of current from the power supply to the signs, you need some serious cable. For comparison, 12 gauge Romex (used for house wiring) is only rated for 25A.

For power that high, you need to talk to a locally certified electrician and have them tell you both the technical and legal requirements in your region.

[leoneckert]

Thank you so much Mike,

one more question, I thought about a different circuit (attached).

Is it right to think that I can delegate the amps of the power supply onto the three different cables. Each of the cables would than only carry a third of the current and therefore could do with more AWG?

If that is right, is there a good way to attach these relatively thick cables to the small strip connections, the arduino and the capacitors?

What about the lights themselves, apologise the question, but do the have a AWG number as well? is there the risk of them (or rather the connections between them) to get really/too hot?

If I guide the lights around a curve, I cut and connect them with smaller pieces of cable, does this cable need to have the same AWG as the (red and white in my attachment) cable doming directly from the power supply, or can I connect small pieces of strip with thinner cable?

Thank you so much for your help, it is hard to get proper advise from my local electricians.
Leon

[adafruit_support_mike]

We suggest making VCC and GND connections about every meter along the NeoPixel strips.

If you try to send power farther than that, the resistance of the traces along the strip and the current consumption of all the pixels along the way will reduce the power to the point where the last ones can't light fully. Since blue and green LEDs operate at a higher voltage than red ones, the blue end is first to go, followed by the green. The result is what we call a 'red-shifted' strip:

https://learn.adafruit.com/adafruit-neo ... ting-power

You can use multiple cables to carry power, and that will reduce the amount of power any single cable has to carry. For a system with that much power, you should really get in touch with an electrician who's licensed in your area though. Not only are there techncial challenges, there may be laws you don't know about, and there will definitely be safety practices you should learn from a qualified professional.