Figuring out power requirements

Hello all! I’ve recently learned about this controller and I’m super excited to get into it, and to contribute to this community.

My project is adding LED strips to my sailboat. I’m trying to figure out how I should power all the controller/strips. The boat is 12v, so I need to use DC to DC converter to 5v. I’m trying to figure out if I should get a converter for each strip/controller or if I should try to run multiple strip/controller combo. And if I should power the LED strips separately from the controllers.

The strips are 144 per m, SK9822 from the electromage store. And the controllers are v3 standard.

There is going to be 5 strip/controller combinations. The max number of pixels on one controller is going is 245 (1.7m). Here is the breakdown:

  • 2 strip/controller combos with ~245 pixels
  • 1 strip/controller combo with ~175 pixels
  • 2 strip/controller combo with ~91 pixels

I currently am looking at this 12v to 5v converter, either the 10a version or the 15a version. I’m not sold on this converter, so if you have a better suggestion, I’m all ears.

What are your thoughts?

I recommend the Pro expander for this, it will let you run multiple lines out and has fuses w/ blown fuse indicators which are especially important for boats! It also has a 12->5v converter option for powering the controller. Unless you are trying for crazy fast framerates, you can drive a lot of pixels from a single controller. It looks like you have 847 total pixels, which is just fine for a single controller.

There are 8 output channels for data or clocks, and you can share clock lines so you can drive all 5 strips from one expander.

The LEDs will use a surprising amount of power, and many converters voltage will droop when under load, so I recommend getting a larger converter, or use multiple converters.

For multiple converters, you could run the expander on 12V, and have the converters after the output ports.

For these SK9822, figure on 50mA worst case power per pixel. Thats showing 100% white (which turns on all R+G+B elements). It adds up quickly, 43A in total. Drawing a color will be about 1/3rd of that. You can limit max brightness to reduce total power draw as well.

The Pro expander is rated for 15A, so using a 12V power distribution with converters after the expander might be your best bet, as they will draw less than half as much current as they output when going from 12->5V. Using 3-5 of the smaller converters might end up costing less than a giant converter too.

First off, thank you for your prompt advice and very quick turn around on my first order!

Let me make sure I understand you. The wiring would look something like this?, except I should get the 5amp version of the converter.

I should choose the 5v (no converter) option to go this route?

Would I still be able to control each strip independently with only one controller?

also since someone else didn’t already ask and you didn’t mention it yet - WS2185 strips can run natively on 12V which may be easier for you to wire up without needing converters (assuming it’s a clean, stable 12V)

also since you’re on a boat, you could also look at this 12V-5V converter which may be easier to weatherproof. i’ve used a few of those for burning man projects and they’re basically waterproof, dustproof, etc etc. (i use marine grade butt connectors for connecting the wires)

Yes, exactly. That’d be the wiring for one of your five channels. I want to point out the terminology here: Wizzard is suggesting you run the whole thing off one controller, which is split into 5 channels with the pro output expander.

It sounds like your largest channel is 245 pixels. At 50mA max per pixel, you’d need 245 * .05 = 12.5A to run that once channel strip at full intensity. Instead, if solving only for this one channel, you could use the 10A DC-DC converter shown in your diagram, and set the Pixelblaze controller to limit brightness to 10/12.5 = 80% brightness. You’ll barely notice the decrease in maximum intensity. Plus, driving the 144/m strips at full white gets very hot, very fast.

Now, since those 245 LEDs consumed all that current, you’d use additional DC-DC converters (after the 12V coming from the pro expander) to power the other channels.

There’s an onboard regulator on the pro expander which will take your 12V boat power and regulate a lower curent 5V to power the Pixelblaze controller. That 5V isn’t passed to the outputs on the expander though - the 12V input power it. That’s why your diagram, which included the 12V->5V DC-DC converter is correct. If you were using Timster’s suggestion to use 12V WS2815 strips, you wouldn’t use this converter. I agree with him on the choice of converter - I’ve had good weatherproofing experiences with the silver finned ones.

(Apr '23 edit: Now the new Sync feature is a potentially much more elegant solution to this.)

Yes, but if you’d like each of your 5 channels to play a different pattern at the same time, you’ll need to use ZRanger’s “Multisegement” pattern and adapt other pattern code into this Multisegment pattern. If you want 5 separate web pages, one to select independent patterns for each channel, you could use 5 Pixelblaze controllers with no output expander. This is less code to mess with, but harder to coordinate anything across the 5 independent controllers.

Let’s clarify this for folks, since I see a lot of these questions about larger installs:

While @wizard is discussing/planning ways to “sync” multiple PBs, right now, there is no syncing (there is time syncing, so that they’ll align, but no way to make some “follow” others, unlike WLED where you can do this) and especially not if you want to add a sensor board. (Yes, technically you could make one sensor board talk to multiple controllers via wiring, but… Not simple and out of the box)

If you want this effect:
all of the lights work together easily

Then use a single controller if your total LED count is reasonable, depends on lengths, output expander(s), etc. This means the whole set of lights are under one control. Yes, you can adapt things to run “multisegment” but it’s also not out of the box easy. Which lead to the alternative…

If you want this effect:
I have distinct groups of lights and want to control them as parts not at all at once, so maybe I can light just some, or dim others, or turn off most of them, or make them do different things.

Use multiple PBs, as opposed to one PB.

You’ll have more work to make them do things since they each have their own control panel, etc. Automation can help here, since you can tie them into an overall control scheme using WiFi and some form of scripting/automation software. But again, non trivial, and more complex than the single controller approach.

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@jeff I’ll certainly be limiting brightness. The room itself is only 12ft x 11ft, and just the 1m strip at full brightness was ridiculous for the space.

@timster I’ve used that very step down converter at Burning Man for a large light pole camp beacon. Using Cool Neon TCL stuff. It probably is a better product.

@wizard The Pro expander seems like a great idea if I wanted all the strips to be in sync, which I do not. Also, if I have separate controllers then all the wiring I have to run through the complicated boat maze is power. These will all be connected to a 20 amp breaker switch at the panel (brightness will be limited).

Plus, I love the idea of building out my own UI to control them independently.