Power Injection Sanity Check - 47" Ice Princess

Pavle

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Just want to validate my power injection on a 47" Ice Princess (Boscoyo) with 550 pixels.
I've watched this xEssentials PI video multiple times, so just clarifying a few things:

I am using 5v pixels and split across 2 ports of a falcon F16V3 and I've got a single LRS-350-5 powering controller and this prop.
  • String 1 running 400 pixels
  • String 2 running 150 pixels
According to the tutorial I linked, no power injection run should exceed 350 pixels with 14AWG (this is what I am using). After pushing the pixels, for testing I have tied pixels 101, 201, 301 to a power injection source, I then have controller power and data in at pixel 1 and 401 and finally I've got separate power injection runs at 400 and 550 (end of stings) - this was successful and all pixels powered up with as best I can tell displaying accurate colours running at 30% (Hopefully I've got 100% also covered in this scenario)?

Is this acceptable to permanently do it likes this or what would you suggest I change before I make it permanent?
 

Bryan H

Bryan
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Its not an written thing, but like to I power inject every 100 pixels. Just looks neater and I think that at 30% white with your current set up will show some yellowing on string 1.
 

Notenoughlights

260,000+ twinkly lights
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Its not an written thing, but like to I power inject every 100 pixels. Just looks neater and I think that at 30% white with your current set up will show some yellowing on string 1.

I stick to this idea (with my mega tree it's every 73 pixels but in each direction) and i've yet to have any issues either with full brightness or lack of power delivery.
 

Pavle

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Its not an written thing, but like to I power inject every 100 pixels. Just looks neater and I think that at 30% white with your current set up will show some yellowing on string 1.

I’ve got power at 1, 101, 201, 301 and 400 - isn’t that every 100 pixels?
 

i13

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Assuming that you're power injecting in both directions then I agree that this is probably overkill but there is nothing wrong with it. If you only want to run the pixels at 30% brightness then the power injection points can be further apart. It is okay if voltage drop causes incorrect colours at 100% brightness; you just ideally might want to avoid overloading anything at 100% brightness.

The wire thickness and spacing between the pixels will affect the number of injection points required.
 

Pavle

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Assuming that you're power injecting in both directions then I agree that this is probably overkill but there is nothing wrong with it. If you only want to run the pixels at 30% brightness then the power injection points can be further apart. It is okay if voltage drop causes incorrect colours at 100% brightness; you just ideally might want to avoid overloading anything at 100% brightness.

The wire thickness and spacing between the pixels will affect the number of injection points required.
I’d prefer to do it once and not have to make adjustments later. Everything I’ve seen recommends that 5v pixels require power injection at both ends of a 100ct string so that you can count back 50 nodes from the power injection point. Just wanted to check myself before proceeding.

assuming I run it at 100% and no fuses pop, am I then only looking for something heating up as a check? If this is all okay and there is no heat detected, I’m good? If that’s correct, how long should I run for continuously to check this?
 

Katekate

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the first thing you should be looking for is inconsistent colour or brightness. run it 100% in every colour and see how it looks.
 

djgra79

My name is Graham & I love flashing lights!
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I don't use a rule of which number pixel to inject at. Similar to Kate above I just test at 100% and see where it looks off in colour enough that it would annoy me and then inject around that point.
Whilst I build to work at 100% I will never run at this brightness, especially at full white. So with colours bouncing around even at 100%, chances are you will not tell the slight colour difference from left to right side of a prop, unless possibly a matrix or HD coro item.
 

Pavle

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Power injection has just about sunk in now with only multiple power supplies left to tackle.

have successfully powered a total of 950 nodes simultaneously so well on my way - thanks for all the continued support

BA9141E9-C5E1-4B16-9AB9-4FFCCA217989.jpeg
image captured from RGB Sequences: Aladdin- A whole new world
 
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pixelated

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There is an interesting "PIxel Light Power Calculator" here: Pixel Light Power Calculator It shows you graphically the voltage drop and allows for multiple power injection points. It might be useful just to get an idea of what may happen in a particular design.
 

TerryK

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There is an interesting "PIxel Light Power Calculator" here: Pixel Light Power Calculator It shows you graphically the voltage drop and allows for multiple power injection points. It might be useful just to get an idea of what may happen in a particular design.
Thanks, I have used that tool and it's very helpful
Please note that the calculator does not seem to be designed to properly calculate strings with V+ broken at power injection points. There was a fairly recent thread regarding this. Refer to Thread Title: Powering two LRS-350-5's from the same power cord and best practice
There
also appears to be an interaction between the pixel wattage and drive intensity (somewhat expected).
 

pixelated

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Thank you for this information. I suppose it assumes only one power supply. I tried to find contact information for the site but there appears to be none.
When V+ is broken this is due to another power supply being added. You could treat each new power supply section separately as it does not affect any other section. The pixel count would start again from 1 on the graph but could be renumbered when printed out. The graphs for the different sections could then be connected to give the whole picture. I found the post you referenced and that is what they did. However, there appears to be no way to not start at pixel 0 for the first point.
 
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