Author Topic: Power draw question  (Read 2047 times)

Offline fatcat46

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Power draw question
« on: September 22, 2016, 10:47:53 AM »
I am building a 16 string mega tree. The lights require 66mA each. Each string has 100 lights for a total of 6.6 amps. More than the power distro or the f16v2 put out per port. My plan is to NOT use the F16v2 to power the tree, just to control it. I was going to combine two stings together with a "T" and use 4 ports off the power distro board to feed power to each. Now it dawns on me that the distro board can't handle that because 2 strings requires 12.12 amps. Even 1 string can't be powered off one port because it's over the 5 amps. I was also planning to use two power supplies for the tree

My question is can I combine the power from 3 power ports (15amp) into one wire and connect that to my 200 lights?

Thanks for any help.
FatCat46

Offline JonB256

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Re: Power draw question
« Reply #1 on: September 22, 2016, 01:28:05 PM »
I have never seen a 100 count string of pixels overload a 5amp channel fuse.

If you are truly worried, power inject at the end of each string.

Offline fatcat46

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Re: Power draw question
« Reply #2 on: September 22, 2016, 01:46:44 PM »
I have never seen a 100 count string of pixels overload a 5amp channel fuse.

If you are truly worried, power inject at the end of each string.

JonB256,

I am only going by the specs for the lights https://www.aliexpress.com/store/product/18AWG-wire-100pcs-string-DC12V-12mm-WS2811-addressable-RGB-led-smart-pixel-node-with-all-BLACK/701799_32599191945.html

If I understand you correctly, you are saying That I would put a "T" at the beginning of the 1st 100, connecting power from the power supply along with ground and control from the F16v2. Then, also put a "T" between the 1st 100 and second 100 injecting power to both the end of the 1st 100 and beginning of the 2nd 100. Repeating that for each set of 200 lights.

I assume I can the use the disrto boards to do the power injecting.

Offline JonB256

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Re: Power draw question
« Reply #3 on: September 22, 2016, 03:26:22 PM »
That sounds right.

If you use two power supplies, be sure to run a ground wire between them. Can be a lighter gauge than the normal Pos and Neg wires.

Offline AAH

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Re: Power draw question
« Reply #4 on: September 22, 2016, 05:17:45 PM »
The design spec for 2811 gives a current of 18.5mA per colour per pixel. This equates to 55.5mA per pixel at full white. I would think the 66mA is a typo. A 5A fuse is never likely to blow at the 5.5A that the 100 pixels will draw.

Offline rich_schultz

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Re: Power draw question
« Reply #5 on: September 22, 2016, 05:17:51 PM »
What I have done is pull the data line off the board and connect the power and ground wires through an inline fuse direct to the power supply. I find it easier to have a "power" strip inside my boxes so I don't have to mess with the limited current capacity of each port.


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Offline fatcat46

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Re: Power draw question
« Reply #6 on: September 22, 2016, 06:14:12 PM »
Thanks everyone. I think I understand now.

 

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