DIY LED Using 10 Watt Arrays

[mike31154]

Decided to document what I'd like to do with respect to LED lighting for my 77 gal tank. I've been fence sitting for some time watching various builds etc & finally decided to do a bit more than experiment, although this is really still just that, an experiment. While I'd love to get my hands on something like an EcoTech Radion, they're just a bit too rich for my budget at the moment. I have some knowledge as far as electrical gear goes, so a DIY lighting fixture should not be a problem & save me a few $$ in the process.

I'm not a fan of builds with massive heatsinks and have been looking for a somewhat lighter & more elegant solution. Some of the more costly commercial fixtures like Radion, Orphek, Kessil have caught my fancy since they seem to be able to get the job done without a 50lb piece of aluminum to draw heat from their LEDs. A reasonably sized heatsink with a fan or two is more to my liking.

Inititally I'd been looking at an MR16 two pin bulb solution. They're designed to run off 12VDC, so with a 12 Volt power supply, some MR16 LEDs & sockets to plug them into, I figured that would be a good way to go. Have a few 4 watt (4 x 1 watt) MR16s in cool white as samples that I'm using above the kitchen sink as task lighting.



These are great little lamps with heatsink & current limiting circuitry incorporated, but they do seem to run a little hot after being on for a while, so not sure whether they'll last the advertised number of hours before giving up the ghost. So far so good, perhaps the heatsinks are doing their job & my fears are unfounded. There are few to no threads on anyone using these over their tank, FOWLR, softie, LPS or SPS. Nevertheless, I'll keep my options open, since once the sockets are wired up to a 12 VDC supply, they're plug & play, easily replaced. Worst case, I can even disassemble them & replace the individual LEDs.

Since I'm on a 12 VDC kick as far as power supplies go, I've decided to pursue the 10 watt LED array route. Several manufacturers are now using similar arrays as a LED option for aquariums. Arrays can be had that run at over 100 watts. They're now available in many different colours, including UV & combo colours on the same chip. The combo chips are an interesting development since they should minimize the disco ball effect reported from many builders using individual 3 watt LEDs of different colours. They all use between 9 & 12 VDC running at 900 to 1000 mA. So close to 10 watts each at the rated voltage. I already have 4 cool white (6,000 to 7,000K) versions of these. 10 Royal Blues came in the mail yesterday & ten 10,000K arrays are enroute. Should be plenty for my 77 including spares.



Now to the heatsink issue. I already have two small heatsinks with fans designed specifically for these arrays & 10 more on the way. What I'm thinking is to use two aluminum rails in parallel & screwing these heatsinks into them. The heatsinks will span the two rails & serve to hold them together. I'd like to tap the heatsinks & mount each array with two screws in addition to using heatsink compound. Even with the tiny fan, these are very light, so the fixture should be light & open for air circulation as well.



Last but not least, there are optics available to fit over these. I'm thinking of trying without to start & go from there. Here's a pic with all the goods(except the power supply).



Stay tuned.