LED Consult

[siege]

Most wise and noble LED gurus, I beseech thee for feedback...

 

I'm planning an LED array for a 50 breeder, the size of which is 36x18x18, and the lights will be placed 6-8" above the water line. I'll eventually be keeping SPS and clams, so I need the power and I'm looking for even coverage.

 

Right now I'm looking at:

 

24 x XP-G cool white

24 x XR-E royal blue

4 x ELN 60-48D drivers

 

I'm planning to use 16 of the HeatsinkUSA 7.28"x1" sinks, with 3 LEDs per. With even spacing, that should give me one LED every ~ 3-3.5" in both dimensions. I'd like to rig the meanwells up to an Digital Aquatics Advanced Light Controller for dimming on/off. As I understand, I'll either need 2 ALCs, or I'll have to rig up a buffer circuit so one ALC can control four drivers (2 per channel).

 

So, questions... Are my plans sound? Is there a better choice of driver for my application? I'm already using DA equipment, so I'd like to use something compatible with the ALC. I see Nanotuners is leaning towards TRC drivers (including placeholders for some new models), but I dunno anything about them. Can someone enlighten me? If I could get down to 2 drivers on a single ALC, that would be great.

 

Thanks in advance.

[evilc66]

That should work out ok. Are you planning on lenses? With the height of the tank, and the distance off the top, you should be. 60's will work fine.

 

What you have planned will work with the Reefkeeper. If you want to reduce the driver complexity, there are two options. 4 of the 40W 700mA TRP drivers will work on a single ALC module. The current draw on the dimming circuit on these drivers is considerably less than any of the Meanwells. If you want to reduce the driver count, then a pair of the 75W 700mA drivers will do the trick. 700mA is still going to be enough light once you factor in optics, and the greater efficiency of the XP-G LEDs.

 

I'd go with a different heatsink setup though. What's your reasoning for using a ton of small heatsinks? Larger heatsinks provide a greater safety net, as well as more surface area for layout flexibility.

[siege]

Thanks for the info on those drivers. If the TRPs pull that much less current on the dimming circuit, then I guess it's way more economical to go with them and remove one ALC.

 

Yeah, I was planning on 60 or 80 degree optics. Guess I forgot to mention that. I'll go with the 60s.

 

I was planning to use the smaller heatsinks because of the weight to distribution ratio. In order to spread the LEDs out as evenly over the tank, I'd need way larger heatsinks, which is more weight over the tank. I was thinking of lining them up in rows, making air channels, and then cooling each row with a fan at the end of the channel.

[evilc66]

There are other ways to get larger heatsinks than going with big units from the likes of HeatsinkUSA. The more interconnecting mass you have, the better. It helps to create more even distribution of heat, and fewer hotspots.

[siege]

The major alternative to a heavy finned heatsink (that I know of, at any rate) is the DIY c/u channel fixture that's becoming popular. My concern is that I keep hearing mixed reviews about how hot they get... probably because if one uses the hardware store stuff, it's relatively thin, light weight stock. So I could make a physically larger heatsink, but it would have less mass and less surface area, and be less efficient for cooling.

 

My original plan was to use numerous smaller heatsinks and ensure they're all being effectively air cooled. Maybe I should take a look at a hybrid approach. Smaller sinks rigged together with aluminum angle stock. Or maybe I should bite the bullet, get a couple of big heavy sinks, bolt 'em into my canopy really well, and be done with it.

 

Decisions, decisions...