Can HBLED drivers be used to power neopixels?


#1

I am using neopixels for my lightsaber project and I was wondering if I could use the HBLED drivers to drive my neopixels? Since I’m using a single 18650 battery to power my project, my neopixel strip only draws about 1A of current directly from my battery since I’m not able to supply the full 5V they are rated for, but the specs of the strips say it can draw up to 40W at full power (8A). The drivers say they can output 4A each. I don’t know what mechanism they use to supply power i.e. voltage step-up or simple current limiting drawing power directly from the battery. Would I be able to slightly re purpose the drivers to drive my neopixels safely at 5V?


#2

Hello @Ryan_Pelo,

I’ve successfully used neopixels with 3.7V power sources. I didn’t measure the time it worked, though.

To answer the question, the HBLED driver cannot supply power to the neopixels. They are conceived to drive high-brightness LEDs at 1A each (the component can handle up to 4A, but the feedback resistors are set to stay at ~1A).They work as a buck (step-down) converter.


#3

If I was to use two cells for a 7.4V power supply, then could I use the drivers to step down the voltage to drive my neopixels? If so, which resistors do I need to remove and what do they need to be replaced with? I really want to get maximum brightness. I viewed a significant brightness increase when going from 3.7V up to 5V and there is simply not enough space to add another step-up/step-down converter inside the lightsaber.


#4

Hello @Ryan_Pelo,

The LED drivers cannot be used that way. In other words, would be extremely difficult because they regulate current instead of voltage. They are still step-down regulators since the output voltage is less than voltage used to power them, but the voltage varies according to the current consumption of the LEDs.