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Thread: Power Supply Limits and Control of Brightness

  1. #1
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    Default Power Supply Limits and Control of Brightness

    I have successfully connected my first three mini trees and have them running my schedule from my Falcon F16V4. Frankly, I'm quite pleased with just those props, but of course I have many more lights to add. The trees are using 296 pixels. Then, I have two 143 pixel Chromabulbs and a 316-pixel custom model I am creating along with the house outline, which I expect to use another 330 pixels. So, I will have a total of 1,228 pixels or so.

    I'm not sure the wattage of the pixels. The Amazon page shows 0.6 watts/led, but the company's website shows 0.3 watts/led. This means I would be running 368.4 watts at full white/full brightness based on the company page and 736.8 watts per the Amazon page.

    I have a 350 watt power supply already set up with my controller and a second power supply that is not yet installed in anything. I'm not really sure yet how to set utilize the second power supply. I'm sure it's not difficult and I could figure it out, but it would be nice if I could skip the extra learning curve for this year. Assuming the lights are 0.6 watts, I would need to use the second power supply and even then would not be able to run the lights at 100%. Frankly, I wouldn't mind running the lights at 40% (that would be 295 watts, about 85% of the power supply), but that brings me to my question: How do I make sure that the lights run at 40% so I don't overload my power supply?

    I am pretty sure I saw that the ports on my Falcon F16V4 were set to 40% brightness. However, now that I connected xLights to the controller, it is using ZCPP and the option for output settings/brightness is of course gone. I see that I could set the brightness in the controller visualizer, but xLights won't let me access that (perhaps because it is ZCPP?). Is the only option to set dimming curves on each model? Is there a similar overall brightness setting in xLights that I can set and forget to make sure I do not use over 40%? Last thing I want is to forget to set a model appropriately and fry the power supply/board.

  2. #2
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    Default Re: Power Supply Limits and Control of Brightness

    Quote Originally Posted by oyarsa View Post
    I have successfully connected my first three mini trees and have them running my schedule from my Falcon F16V4. Frankly, I'm quite pleased with just those props, but of course I have many more lights to add. The trees are using 296 pixels. Then, I have two 143 pixel Chromabulbs and a 316-pixel custom model I am creating along with the house outline, which I expect to use another 330 pixels. So, I will have a total of 1,228 pixels or so.

    I'm not sure the wattage of the pixels. The Amazon page shows 0.6 watts/led, but the company's website shows 0.3 watts/led. This means I would be running 368.4 watts at full white/full brightness based on the company page and 736.8 watts per the Amazon page.

    I have a 350 watt power supply already set up with my controller and a second power supply that is not yet installed in anything. I'm not really sure yet how to set utilize the second power supply. I'm sure it's not difficult and I could figure it out, but it would be nice if I could skip the extra learning curve for this year. Assuming the lights are 0.6 watts, I would need to use the second power supply and even then would not be able to run the lights at 100%. Frankly, I wouldn't mind running the lights at 40% (that would be 295 watts, about 85% of the power supply), but that brings me to my question: How do I make sure that the lights run at 40% so I don't overload my power supply?

    I am pretty sure I saw that the ports on my Falcon F16V4 were set to 40% brightness. However, now that I connected xLights to the controller, it is using ZCPP and the option for output settings/brightness is of course gone. I see that I could set the brightness in the controller visualizer, but xLights won't let me access that (perhaps because it is ZCPP?). Is the only option to set dimming curves on each model? Is there a similar overall brightness setting in xLights that I can set and forget to make sure I do not use over 40%? Last thing I want is to forget to set a model appropriately and fry the power supply/board.
    Basic PIXEL math: internally each PIXEL has 3 LEDS. Each has a current requirement of .02a or 20ma. Each pixel can draw up to 60ma, white. The math: .06a * 12v = 0.72watts

    AMAZON IS NOT THE PLACE TO LEARN. You came to the RIGHT PLACE. Amazon is full of garbage and BAD information. It is their vendors that do not have a clue what they are doing, mostly.

    Oh, a note on PSUs ... I had 6 PSUs - 12v 360w NEW - each one got tossed because the output was 1) non-adjustable 2) 11.6v out and fell to 9v with a 10 amp load. They got tossed because they were sitting on a shelf for a few years.

    Try to always get the same PSU brand if possible. I found Meanwell and some others are pretty reliable and maintain a good output up to 90%. MOST power supplies will dip badly beyond 90%. You will pay a bit more and get some peace of mind in return.

    PSUs have internal AC fuses and many have current limiting and some have thermal limiting. It is the really cheap supplies that have no real internal protection and will run until they burn up.

    Hope this helps.

    Oh - I design, build and maintain commercial displays with pixel counts into the 8,000+ pixel range per controller - I suppose I am a PIXEL Addict
    Last edited by RGB_Mixer; 11-20-2021 at 04:46 PM.
    -Eddie

    The missus wants to ride!

  3. #3
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    Default Re: Power Supply Limits and Control of Brightness

    Thankfully, both my PSUs are Meanwell.

    Sooo...now I am trying to figure out how to make my setup work and what more I might need. Based on the 0.72 watts per pixel, with my Falcon F16, I could only run 388 lights total (using 80% of the power supply and at full brightness) with the power supply included (it's a ready-to-run package). So, that would be only 25 lights per port. Even if I added a second supply to the board, that would only be 50 pixels per port. Granted, I'm not going to use that many ports, but how is a person suppose to utilize even the 16 ports of the F16, much less the 32 or 48 of the other F32 and F48? Running at 50% brightness could double that, but still. So how do you manage 8,000 lights per controller? Do you only use the data line from the port, and get power supply completely separate from the controller?

    In my case, I can use 6 of my ports.

    1: Trees (296 pixels)
    2: Garage (180 pixels)
    3. Garage Peak (150 pixels)
    4. Bulb characters (286 pixels)
    5. Custom model (316 pixels)
    6. Porch outline (180 pixels)

    If I start power injecting with my second power supply at pixel 100 of each port, I would be at 600 pixels for the controller power supply and 808 pixels for the second power supply. At 40% brightness, I should be fine. Am I thinking right? Feels like I must be missing something because I get the impression that people run quite a few more lights off each power supply...

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    Default Re: Power Supply Limits and Control of Brightness

    Quote Originally Posted by oyarsa View Post
    Thankfully, both my PSUs are Meanwell.

    Sooo...now I am trying to figure out how to make my setup work and what more I might need. Based on the 0.72 watts per pixel, with my Falcon F16, I could only run 388 lights total (using 80% of the power supply and at full brightness) with the power supply included (it's a ready-to-run package). So, that would be only 25 lights per port. Even if I added a second supply to the board, that would only be 50 pixels per port. Granted, I'm not going to use that many ports, but how is a person suppose to utilize even the 16 ports of the F16, much less the 32 or 48 of the other F32 and F48? Running at 50% brightness could double that, but still. So how do you manage 8,000 lights per controller? Do you only use the data line from the port, and get power supply completely separate from the controller?

    In my case, I can use 6 of my ports.

    1: Trees (296 pixels)
    2: Garage (180 pixels)
    3. Garage Peak (150 pixels)
    4. Bulb characters (286 pixels)
    5. Custom model (316 pixels)
    6. Porch outline (180 pixels)

    If I start power injecting with my second power supply at pixel 100 of each port, I would be at 600 pixels for the controller power supply and 808 pixels for the second power supply. At 40% brightness, I should be fine. Am I thinking right? Feels like I must be missing something because I get the impression that people run quite a few more lights off each power supply...
    You have the right idea. However, power injection will TIE the power supplies together. I use amperage calculations and the 80% rule in designs. I avoid driving PSUs harder than 80% of output, 90% if absolutely necessary. The reason for power injection is due to the construction of the pixels themselves. The wire is the problem. It cannot carry the current beyond "X" amount of pixels. It is too small. This is the only reason we power inject strings.

    I have found a source where the V+/V- is made with #16 wire. That is good for around 500 pixels before PI is needed. I did see one EXPENSIVE string made with #14 conductors for power.

    In real life measurements, a 300 amp PSU bank, ALL WHITE = 5000 pixels @ 100% PSU load. PSU voltage output will drop as much as 20% or more. 9.6v is enough to maintain a good light output. Some pixels will get "stupid" below 9v on a 12v system (erratic behavior).

    The real life aspect: there is no way displays are going to be nothing but all white - that is a duty cycle of 100%. Majority of the time the duty cycle on most displays will be around 50%. So unless your display calls for allot of FULL WHITE (every pixel), you will not tax the PSUs to 100%.

    The idea is to maintain voltage. The wire (copper conductor) DC characteristics are very different than AC characteristics. AC wire length can be 2x longer than DC, as a general rule. The lower the voltage, the harder it is to maintain. I.E. 120v AC no real big deal. 12v AC can be difficult. 12v DC will be difficult. I also use 5v and that is a bear to maintain.

    When you take into consideration the duty cycle, that is how some folks can put 6000+ pixels on a power bank of 300A. I look for ALL WHITE to ensure my displays are balanced throughout. Any sign of a 'VISUAL' deviation needs attention (for commercial customers).

    Average folks will not be too disconcerted over that.
    -Eddie

    The missus wants to ride!

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    Default Re: Power Supply Limits and Control of Brightness

    So, even if the positive wire is disconnected at the power injection point, the demands are shared by the two power supplies?

    In real life, how many pixels do you assume one 30a/350 watt supply will cover? How do you monitor how much power your display actually uses?

    When you need more power, how do you apply it? Through several power supplies chained together from one distribution board? I assume something completely separated from the control board, correct?

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    Default Re: Power Supply Limits and Control of Brightness

    My 360 watt 5v power supply is driving 1000 pixels and the voltage only dropped from 5.2v to 4.9v. At this point, I just add strings until I see a problem.

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    Default Re: Power Supply Limits and Control of Brightness

    Other factor in power injection is, pixel strings only occasionally go straight. String chains can zig zag a lot. Power injection wires can take a more direct route (which pretty much describes my entire morning today--routing power).

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    Default Re: Power Supply Limits and Control of Brightness

    One thought - you will be surprised how low you can go on brightness and still be very bright. Got 20% of my props up last weekend and had the controller at 40% brightness which was basically blinding. Moved it to 20% and settled on 13% brightness after last night and its still BRIGHT.

  9. #9
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    Default Re: Power Supply Limits and Control of Brightness

    VERY cool Good to hear.

    My experience with lower outputs affects the darker colors the most. When I run twinkle in the mix, I want to see "WHITE". It is that dynamic range that compels me to build it right so it can run @ 100% no matter what. WHITE is right.

    My PSU banks are usually 110% of what I need.
    -Eddie

    The missus wants to ride!

  10. #10
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    Default Re: Power Supply Limits and Control of Brightness

    Quote Originally Posted by oyarsa View Post
    So, even if the positive wire is disconnected at the power injection point, the demands are shared by the two power supplies?

    In real life, how many pixels do you assume one 30a/350 watt supply will cover? How do you monitor how much power your display actually uses?

    When you need more power, how do you apply it? Through several power supplies chained together from one distribution board? I assume something completely separated from the control board, correct?
    Ummm - not if you disconnect a PI point and that was the only point. Is okay to leave the positives connected together. The hysterics between the PSUs virtually become null with the resistance between pixel 1 and PI point @ pixel 100, for instance.

    Hang onto your hat. I RARELY run allot of power through my controllers. I could get away with NO power to the controllers with all the power injection I use. They get their power from the PROPS. I have some DX receivers that I never apply power to. They get their power from the Pixels that are massively Power Injected.

    It depends on your show. 30A w/a 100% duty cycle = 500 pixels. At a 80% duty cycle = 625 pixels. 30a/.06 pixel =500 pixels 500 pixels / .8 80% duty cycle = 625 pixels. This also assumes all outputs are set to 100%.

    Power injection: always tie the negatives. Data requires a reference and it references the negative. Positive can be tied together. Try to adjust and match output voltages on the PSUs ... through diodes, I set @ 12.6v to get a 12v out for power banks. For general multiple power supplies, setting them @ 12.1 with NO LOAD is good. As soon as they see a load, they drop to 12v or a little less = this is acceptable and anticipated.

    Some power banks I use have remote sensing to maintain voltage at the point of consumption over long distances. 4 of these units ganged cost around $1,000.00 - yeah, specialty stuff.

    Anyhow - you get the idea
    -Eddie

    The missus wants to ride!

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