Can you power PixelBlaze via 12v in directly, without a buck converter?

I’d always thought you needed to give the PixelBlaze 5v in, even when using 12v lights, and just tie in a common ground. However, I just noticed that in the page, it reads:

Power: V3 Standard: 4-18 V with reverse polarity protection.

Does that mean you can feed a PixelBlaze 12v for power and it’ll handle it without letting out the magic smoke? I couldn’t think of a way of testing that without, well, destroying a PixelBlaze if I was wrong.

The detailed specs say:

  • Power supply: micro-USB (1.8 A pass-through) or 5 V back-feed from the LED strip, with an onboard 3.3 V regulator for the ESP32 and expansion boards
  • Power protection: reverse-polarity protection and up to 18 V overvoltage protection to prevent damage from common wiring mistakes

Which implies that it would be fine. Obviously that’d be super helpful if so.

Same question for the Pico, if different from the v3; the Pico specs read:

5 V back-fed from LEDs

  • Power supply: directly from the header, with an onboard 3.3 V regulator for the ESP32

P.S. – I know ElectroMage shop sells a cheap 12v → 5v converter, but it’d be a lot cleaner for my 12v LED wiring to not need one.

1 Like

You can, but it won’t run for long. The regulator I use will protect Pb from more than 5v, but running at 12v for any extended period of time generates too much heat, and the regulator will thermally throttle.

1 Like

Perfect. Thanks. It might be worth making that more explicit in the documentation on your website.

1 Like

Agreed, i have been confused in the past. Ended up using a 5V regulator to avoid taking the risk of frying anything.

1 Like

In case anybody is wondering, the control board can handle 12v, but the expander board cannot.
I found that out the hard way and let out all the magic smoke from the expander. The control board still functions, but I’ll need to get a new expander board and a buck converter to prevent future issues.

Does the 12v to 5v mini buck converter available in the store have more oomph than the regulator on the PixelBlaze board itself? It seems smallish, so I’m wondering if it will also thermally throttle when it gets hot due to normal use?

It can tolerate it without damage, but I wouldn’t say “handle” 12V.

The input voltage regulator on the Pixelblaze Standard will prevent damage when given 12V (up to 18V), but while powered it will get very hot and eventually start to cut out as the voltage regulator overheats and goes into thermal protection. It’s a linear voltage regulator, it works by converting any excess voltage into heat, the more excess volts the more heat.

I recommend the mini buck for a 12V system. It has enough power for Pixelblaze, an output expander, and a sensor board, with more to spare. It uses an efficient buck DC-DC converter, which actually converts power from a higher voltage down to 5V with minimal losses, so it is much more efficient and does not generate a lot of heat. I officially rate it for 600mA, but the components are rated for higher and it might still work fine up to 1A. It’s not enough to run a bunch of 5V LEDs on though.

This topic was automatically closed 120 days after the last reply. New replies are no longer allowed.