Matrix Falcon Port Allocation

[Chrisekert]

Hi Team, I have a spare Falcon plus expansion board and this year decided to put together a Matrix for our garage door. We have decided to go 2 Matrix's totalling 2304 12v pixels @25% Brightness which will be 48x48. We have plenty of ports and power supplies - to keep it simple and avoiding to much injection what have others done in regards to running max pixels on each port of controller? Eg can we get away with 16 ports at 144 pixels ? Cheers

 

[uncledan]

I don't foresee any issues with 144 pixels per port without injection, especially if 18AWG. Always best to test. Lots of people go much more than 144 pixels without injection. Sequence played fine for me and no issues with pixels with 696 pixels on port of Falcon with no injection @20% intensity from what I recall. I limit intensity on all my controllers on the port configuration of Falcon not xLights just to be safe

 

[LawrenceDriveLights]

Yes, 144 pixels per port without power injection on lower brightness setting should be ok.
As a rough rule of thumb, most 12v pixels are 0.06 amps or for 100 pixels have a current draw of 6 amps at 100% brightness for white, so technically for 144 pixels it would be 8.64 amps, but as uncledan mentioned and I have experienced a lower brightness setting reduces current draw.

Just be aware if for some crazy reason the brightness setting goes to 100% (can happen if you accidentally forget to set brightness level on controller, or for some other reason the brightness jumps to 100%) you may blow the 5 amp fuse on the controllers output, which isnt a massive issue if you have a spare fuse.

On a side note, i have experienced some 12V pixels from some Vendors have a lower current draw than the "rule of thumb" of 6 amps per 100 pixels.

So I would suggest you invest in a multimeter that can measure amps (most do) and do a quick test for yourself to check current draw.

 

[merryoncherry]

"most 12v pixels are 0.06 amps or for 100 pixels have a current draw of 6 amps at 100% brightness for white"

Regulators do. Resistors do not. And as most pixels are not regulated, the statement above is false. 144 modern 12V wimpy resistor pixels at 100% white are fine, probably draw 3A or less.

 

[uncledan]

"most 12v pixels are 0.06 amps or for 100 pixels have a current draw of 6 amps at 100% brightness for white"

Regulators do. Resistors do not. And as most pixels are not regulated, the statement above is false. 144 modern 12V wimpy resistor pixels at 100% white are fine, probably draw 3A or less.

60ma is the norm for 12v pixels in the hobby and a safe number. I wouldn't say the statement is false when you have no clue what pixels the user is using. Always better to be safe than sorry(and test of course). I know you're new to the hobby but 60ma for 12v node has been the norm for years and is a good safe number to use. Regardless you should be fine @Chrisekert

 

[Chrisekert]

my similar size matrix of 24x92 (2208 px) I run on 2 falcon ports with 2x power injection at the 500px and 1500px marks @30% - no reason you shouldn't be able to run the whole thing without injection at 12v on 4 ports

Oh wow ! Nice one

 

[merryoncherry]

60ma for 12V pixels is a safe number, yes, but it is outdated. Designing around that number cost me thousands of dollars for extra power, ports, and cables and many hours of time screwing together connections and entering them into xLights. (To those who think I may sound bitter about this... yes, yes I am.) Every time somebody repeats that outdated information, it costs some newbie time and money.

I did not make this up, I measured it and documented it quite carefully for you all here: https://auschristmaslighting.com/threads/which-pixels.14637/#post-125697

I was very clear that 12V regulator pixels are still in the 50+mA range, and that it is only modern 12V resistor pixels that are significantly less... but those are the most popular when purchasing today. I did neglect to mention that the 12V resistor C9 and rectangle modules seem to use a higher wattage also, but assumed people weren't using them for matrixes (C9 matrix would be cool though). A couple years ago, regulator pixels were the best. But the only reason to use a regulator pixel these days is if you need extra brightness and are designing to run it at 100%.

Yes, I'm inexperienced, so you have to decide if you want the advice of the experienced person who has a rule of thumb from years ago, or the n00b who collected data on the pixels he got last month. Probably best to hear from someone with experience, and who also has hard data, so watch the videos from Ni Family Lights, such as this one:
View: https://www.youtube.com/watch?v=bTCcCIw-Kw4

 

[Skymaster]

Ultimately the WS2811 chip is capable of supplying 55.5mA to the three LEDs combined on full white. Now, depending on what value resistor that the particular manufacturer uses for dropping 12V down to 5V can limit the maximum current available. If they use a 120ohm resistor, that would allow the full 55.5mA and provide 5V to the WS2811 chip.

Also - keep in mind that the whole 'resistor/regulator' and current draw arguments only apply to 12V, and only apply to bullet nodes. Strips use 3 LEDs in series in lieu of dropping the voltage, and 5V have no limitations. It also only applies to WS28x1 based pixels, others such as GS8208 use different methodologies and have different current requirements.
The resistor value chosen by some manufacturers will limit to say 30mA or lower for total current draw. This is done to reduce the power wastage in the resistor, inherent in 12V node designs, sacrificing maximum brightness as a side effect.

You're also seriously limited by the gauge of the wire used, 18awg is still pretty tiny wire for the currents involved over more than 50 pixels. This is why the advice to power inject for 5V pixels is at around this mark. 12V has similar currents flowing, however can handle more voltage drop before it's noticeable, hence why PI is not nearly as required. If you run beefy wire to your pixels, no worries, you'll get close to maximum current draw.

60mA per pixel is still sound advice as a starting point - It's a simple easy blanket statement that covers the worst case scenario, no matter the design of the pixel, operating voltage, etc.
Once you work out voltages, how you intend to deliver power to them, what control chip you're using, pixel drive percentage, you can then refine and reduce as required.

I'd also be hesitant in using pixel.report as a definitive source on what's popular. There were really bad questions in it (5V - are they regulator or resistor - well, neither actually) - and the majority of people that filled it out were ones that had problems and/or fires - many people didn't fill it out if they didn't experience issues.

FUD - Fear Uncertainty Doubt - from Pixel Report Feb 2022

FUD - Fear Uncertainty Doubt Likely everyday of the year another person joins the Christmas Light Community because they wish to put on a show just like the person down the road or from that YouTube video they watched. They generally have no idea what they don't know in the pixel world even if...

auschristmaslighting.com

 

[merryoncherry]

Yep, "denominator problem" in pixel report is pretty bad. We don't even know how many pixels are sold, just that 2 big vendors cover 11m pixels. Poor choice citing it on my part, but I was too lazy to write what is now written below.

I won't let go of the main point... 60mA rule of thumb is bad advice for newbies, unless they're explicit about choosing regulators (which they probably aren't because they cost more and are harder to get).

I guess I also got my sense of what's popular for bullet/flats suitable for matrixes a different way... by asking a couple vendors and based on what's actually for sale at vendors:

1. Gilbert: 5V, 12V resistor (personally tested in 2022 at 24mA avg on 100)
2. RGB man: 12V resistor (personally tested in 2022 at 23mA avg on 100), 5V is special order
3. Amazon (usually Alling/Etop): 5V; 12V resistor (personally tested in 2022 at 22-24mA avg on 100)
4. Ray Wu: Wide variety. 5V, 12V resistor, 12V regulated (personally tested in 2022 the 120-node peace stake config at >50mA/node)
5. Wired Watts. 5V, 12V regulated (personally tested in 2022 at >50mA/node)
6. HolidayCoro: 5V, 12V resistor (personally tested in 2021 at 26mA/node for 100, much more power used when off also) (12V regulator in icicle config only at >50mA/node)
7. Mattos: 12V resistor (hope to test soon), 12V regulated
8. Pixplus: 12V regulated (hope to test soon; reports here are they are 37mA/node)
9. Wally: 12V resistor
10. HLS: 5V, 12V resistor, 12V regulator

That's not all of the major vendors, and missing test data for a some too... got a couple orders coming and will update with numbers when I get the product. But clearly 12V regulators have fallen out of fashion a bit, as I was told. 12V regulators follow the design guideline; 12V bullets do not (these days).