WS2812B max amperage

[Matt Smith]

Hi there,

I'm new to the forum and come from a professional lighting background. I'm looking at doing some custom fixtures and from research I'm thinking I'll be going the WS2812B

I need a 60 LED/m 12v unit as these will be portable units.

My question is, I can't seem to find a max amperage rating for the WS2812B Strips themselves. Does anyone know what the actual LED strips can handle. I'm hoping to do a 15AMP cable and power inject every 12.5m (750 LEDS) not sure if I'll get too much voltage drop from this. Is there a way to calculate this accurately or is it mostly experimental?

I've read through the manual and searched the forums but it doesn't seem to explain toooo much. I read the post about voltage drop through cables, all that kind of stuff makes sense

Thanks heaps in advance!

 

[David_AVD]

I'm thinking you'll need to inject power every 4 - 5 metres. The voltage drop at 12.5 metres would be quite severe.

 

[fasteddy]

From memory 2812B current draw is 18.5mA per colour, so that would be 55.5mA per LED

From my experience with the 60 LED/m strip then you will need to inject between each 5 metre strip, or you can supply power in between the 2 strips so the first strip is being supplied from its end and the second strip is being supplied from it beginning. Just make sure the cable you use for power can handle the load of both strips

 

[Matt Smith]

Thanks very much guys,
I've read that 12v systems are less efficient as they have to drop voltage down to the 2v that the LED's require anyway so if one moves to a 5v system do you need to be power injecting even more often than 5 metres?

 

[fasteddy]

Thanks very much guys,
I've read that 12v systems are less efficient as they have to drop voltage down to the 2v that the LED's require anyway so if one moves to a 5v system do you need to be power injecting even more often than 5 metres?

The 2812B spec sheet says that it is a 5vdc input, so the only way I see you would get 12vdc 2812B strip is that it uses buck convertors to bring down the 12vdc to 5vdc, so this means if using it as 12vdc then you can only cut the strip every 1/2 metre as each 1/2 metre section has a buck converter.
If your not needing to cut the strip down then the 12vdc model will give you the best of both worlds, giving you less voltage drop and also running the LEDs efficiently at 5VDC, I'm not sure how efficient the buck converters are
But ive not used this strip before so I cant comment on its reliability

 

[Matt Smith]

Perfect thanks so much, I've ordered some 2812B and a pixilite 16 mk2 so shall be an interesting time!
Shall post how I end up going with it all

 

[Cologne LED]

you'll need to inject power every 4 - 5 metres.