Diy led refugium light

15 1 watt leds at 3.2Vf = 48 Vf total. When choosing a driver you always need to add some extra voltage for overhead for the driver circuit, so you should judge accordingly.

3.2 Vf X 350 mA = 1.12 watts per led x 15 = 16.8 watts of power.It's good to add a 20% cushion to the watt requirement so add an additional 3.4 watts to make the driver requiring 20.2 watts total.

Given that a lot of power supplies and drivers are available at around 48 VDC, you might want to consider paring down the number to 13 leds and come in around at around 42 Vf.

Next question is are you going to dim them and, if so, how? Meanwell ELN 60-48 is a dimming driver that will produce 48 VDC and can be adjusted down from a maximum of 1300 mA to the 350 mA you need. Dimming can be controlled with a pot and a 10 volt power supply.

If you are dimming with a controller that puts out PWM signals you can go with a meanwell LDD driver of the correct amps (350 mA), or wire the leds into two series sets with a parallel input to drop the current from 700 mA to the 350 mA you need. The LDD driver requires a digital input PWM to dim correctly, something like a storm or typhon.

Does that give you the information you need?


Edited by Fatman - March 18 2016 at 11:37pm

The ELN is a great choice. Limit it to 13 LEDs and it will work great. It is a self contained power supply/driver. You will need a 10v 500mA wall wart type power supply to turn it on as well as to use with a 10k ohm pot to dim the driver. Should be a ton of light for a sump light.

9 volt will work you just can't ever get a true 100% on using 9v. You get 10%-90% which is more than good enough for a sump light.

What fatman said but it's getting really hard to find non switching ones anymore. I don't think it's even $2 more for switching. More like .50

Wait another question guys ! So the forward voltage of these LEDs are 350mA,, so in order to use a HDD driver of 700mA I would need to do two strings of LEDs so one of six and one of 7 ,, on that same driver ?? Or am I missing some thing ?

Looks like a fun project. If I had that stuff laying around I too would choose it over the economical "Home Depot Special" I usually use for the Refugium light.

Yes, keeping them closer together will produce more shimmer than if they are spread out then each one produces a different shadow. Those shadows cast in a different locations and cause a larger shadow area which cancels out the skimmer. Single source light (I.E. hallides) produce the most shimmer as every ripple on the water surface produces a matching shadow that moves on the sand without any other shadow interfering with it.

Yeah that's one row of LEDs !! Mine is 5 rows of 22 LEDs !!! Lol disco Bally not so nice shimmer