Power calculation

D

dannyp

Full time elf
Joined
May 12, 2010
Messages
311
Location
Sydney
I have the following lights and am just wanting to check my calculations for how much power they will use and what power supply I will need.

http://www.aliexpress.com/snapshot/6008549881.html. These lights are 12 v

According to the website they use 0.30 watts per light so for every string of 100 they will use 3.0 watts. If I use a 600watt power supply @80% load this gives me 480 watts of usable power. In other words I should be able to run around 160 strings (with suitable power injection) from the one power supply.

This seems like a huge amount of lights from the 1 p/s but I would like someone to please confirm this as power is not a strong point for me. I think I followed the formula in the 101 manual but maybe I stuffed up somewhere.

Many thanks
 
Umm... 100 x 0.3W = 30W, not 3.0W but may be a typo so you'll have to revise that calculation.

I made a LED current calculator that may be of interest. it's on my web site here.

I don't know if I'd trust the wattages quoted on Ray's site.
 
Umm no that was not a typo and was exactly the mistake I could not see. Feel like an idiot but at least I got a calculator for future reference :)

Thanks so much
 
You will be safer using 0.6W for each node. In real life, 100 pixels will use about 5.5 A when all are white. (I am just testing mine right now). So I calculate 6A as the draw for 100 pixels when sizing my power supplies.
 
David your site is fantastic and full of very useful ideas.

Thanks again
 
Not strings but strips (should be close) I measured 3.3 to 3.6amps with all white, center fed between two one meter sections of Plasma Icicles.

So actual per meter of WS2812 (5v) strips was 1.15-1.3amps per meter (including drop for connectors, cable and flexible PCBs), no more than one meter length from any power injection.
 
David_AVD said:
Obviously any strip figures will vary a lot depending on how many LEDs per metre.
Click to expand...

Aaahh.. good point.. mine were 30 LEDs per meter.. and 5v type.

I also found that some strip manufacturers use heavier copper... They cost more, but they don't have as bad of voltage drop issues for longer strings.
 
You must log in or register to reply here.
Back
Top