I'm putting together a light for my reef aquarium and I confirm wether or not my assumptions, about which power supply to use, are correct. I'm using LDD-H dc-dc drivers for powering my leds which are in 4 channels, approx 12v required for each channel(varying current for each). The manufacturer recommends a 48v power supply for powering this array, but I believe that's so that multiple arrays can run on a single psu which I only am going to be running a single one. If my thought process is correct, then there should not be any problem running this same setup off of 24v rather than 48v as long as my wattage input is equal. Is that correct? My led array as a max wattage rating of ~80w, but they won't be run that high as I'm shooting for ~65w. In this situation there shouldn't be any difference wether my psu is 24v 6.25a or 48v 3a as they are close enough in total power. Am I totally wrong or am I on the right track to move forward? I want to make sure before I order my power supply.

Here is the LDD-H datasheet if anyone needs it:http://www.mouser.com/ds/2/260/LDD-H-spec-766227.pdf

 

I would guess the recommendation is about efficiency and heat production. Look at the efficiency curves for 24V input. At 12V out (4 leds @ a Vf of 3), it doesn't look too bad.