lcornelius:
Hi all,
Please point me in the right direction if this question has been asked before.
I did allot of reading on the forum, but can't seem to find a answer.
I'm building a light hood for my 2m x 1m marine tank.
Will be using about 196 CREE 3w LEDs. Will use Cool White, Blue and Royal Blue LEDs.
Well first off, 196 seems like a lot of LEDs for a 6 foot tank. To put that into perspective, the Vertex uses 192 for a 6 foot fixture and they are only run at 700ma, not 1000ma. I am not sure of the way you have them laid out, but if you are going for depth penetration (the tank is 1m tall or wide?) then you can cut down on the LEDs and use optics on LED sections which are above SPS sitting at the bottom of the tank. To put this into perspective again, the Aqua Illuminations sits at about 76 watts per unit and has a feasible foot print of 2'x2' with optics. These are tested and true ultra high powered LED fixtures that will cook your corals at full power. So for starters, you can eliminate some of those mean wells by eliminating some LEDs
EDIT: Looks like you will be running at 700ma, I was confused by the 3watt, you are actually only running 2.4 watts. I still think you can do away with some LEDs though, but really there is a big diff between 1000 ma and 700ma
The problem is that I will need 14 individual Mean Well drivers, 2 per 300mm x 300mm section.
So I think this is not the best way to do it. I would rather run 3 big drivers, one for white, one for blue and one for royal blue.
Now I need a circuit to dimm each block of LEDs.
Well, your choices are limited, due to the fact that high power LEDs gobble voltage, you are pretty much stuck unless you want to go into heavy duty commercial power supplies and have some specialty divers made. However, Thomas Reseach has a 120w driver out that tops out at 114volts and runs at just over 1000ma. It has a 10v dimmer circuit. Feasibly, you can run 32 3watters. The only place I know that has them, is Nanotuners, I believe they have exclusive distro rights in NA. They are also substantially more expensive that the 48v mean wells. They are between 80 and 130 dollars.
Driver at 700mA 3.2 volt
Driver at 1000mA 3.3 volt
The CREE model numers:
Neutral White Cree XP-G LED (XPGWHT-L1-0000-00FE4)
Blue Cree XP-E LED (XPEBLU-L1-0000-00201)
Royal Blue Cree XP-E LED (XPEROY-L1-0000-00B01)
If I were you, I'd consider using a cool white LED instead like XPGWHT-L1-0000-00H51. It will push you to between 5000k-8000k. Also, you get better lumen output from that chip
That being said, I have a question while I am here,
Can you daisy chain all the blue or white drivers together into one PWM channel or does each driver need it's own channel?