LED Design

[coolsurf]

I am presuming you are using 3w?

I've seen it done two ways...both stating positive reults. One is stagering evrey othr LED and the other is rows...alternating every other row (one blue and one white). I have not heard a negative either way.

 

[giulianom]

Here's the full layout, with the two heatsinks.

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26 columns of 9 LEDs (across the two heatsinks), including the split-columns at either end... although I may fix that..


234 LEDs.

I bet I could blind passers by... from my home... in daylight... at half power...

 

[giulianom]

And here's what it would look like, inside the canopy.

Hung ~3" from the top of the canopy.


The idea is that both heatsinks would be hung from the top of the canopy from bolts/standoffs, and that the front heatsink would be attached to the pivoting front section of the canopy.. flip up and out of the way.

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[giulianom]

Re-arranged the first and last columns...

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May switch the colors around depending on the ratios, but I think this pattern is good.

 

[dan30097]

sweet

 

[dan30097]

Wow thats a huge tank. How do you keep it so clean?

 

[giulianom]

I think he meant the other guy's tank pictures (which are nice).

Personally, I draw hermit crabs and snails, and they keep my picture of a tank nice and clean. ;-)

 

[giulianom]

Thought I'd come up with an alternate design.

LEDs arranged in 3-LED triangles, one royal blue, one blue, one white.


On this heatsink 7.28" wide x 54" long, I could fit 75 of the 3-LED pucks, or 225 LEDs.


Perhaps I could go with 1W LEDs with this many instead of 3W LEDs?

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Or perhaps this arrangement is a bit better...

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[giulianom]

Both heatsinks, the front 7.28" and the rear 10":

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175 3-LED pucks, total of 525 LEDs.


I may decide to split them up into 3 x 18" long sections to make them easier to manage seperately.

 

[giulianom]

Removed 7 of the 3-pod LED arrays, making it an even 168 x 3 LEDs (504 LEDs total).


Color coded them into sections, with each section (theoretically) being driven by a Steve'sLEDs quad-driver with 28 LEDs each, 3 per section.

3 quad drivers per section, 6 sections.. 18 drivers..


2-chip 3W Steve'sLEDs...
Probably 2 x 3W Royal Blue, and 1 x 3W 2-chip Cool White 10K per pod.

336 x 3W Royal Blue $3.15 ea, $1058
168 x 3W Cool White $3.25 ea, $546


Overkill? Perhaps...

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[morganatlanta]

That is way way way more than you need. See the PAR numbers from SRA_Chipmunk who did an LED build with Steve's LEDs.

 

[giulianom]

I have no doubt that this is way more than I need...

At this point I'm just playing around with physical arrangements.


I will probably break up the giant heatsinks into 18" sections and work from there...

I doubt the LED pucks need to be so close to each other, too.

 

[coolsurf]

Here is some good information that may help. I've been refering to his thread alot and still asking questions regularly. His is a true success story.

 

[giulianom]

Good reading, thanks!

 

[coolsurf]

NP

BTW, both of us entered into the LED builds with identical MH setups...same bulbs and everything.

 

[giulianom]

Made some further changes in the design...

Six 18" long heatsinks instead of two 54" long ones - 3 of them 7.28" wide, 3 of them 10" wide.


I designed the framework for 1"x1"x1/8" aluminum angle stock, with the corners mitered. I may try to braze the corners together...

The length of the frame is designed to fit the inner length of the canopy, so it should slide right in... Mounting method TBD.


Bottom:

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90 3-LED pucks, centered in a 3" circle.

90 White, 90 Royal Blue (lighter), and 90 normal blue (darker) for a total of 270 LEDs.


Top:

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Top view of the heatsinks.

I may try to design in some fan shrouds, with the fan(s) blowing down the center(s) and out the sides of the heatsink(s).

May also design in some center braces in between the heatsinks.


Thoughts?

Is 270 LEDs closer to a "sane" design?

 

[morganatlanta]

SRA_chipmunk had 1 LED per gallon and got more than enough PAR. I guess you can always turn them down, and you'll be more energy efficient if you are in the right part of the output curve, but you'll be paying more up front for capacity you won't need.

 

[giulianom]

Do I really need 1 Royal Blue and 1 normal blue?

Perhaps I could get away with just the Royal Blue and the Cool Whites...

 

[morganatlanta]

I think it is a matter of personal preference. I have CREE XRE cool white and royal blue (42 of each) on my 125, but I find the royal blue too harsh on my eyes, so I'm adding 42 regular blues (epoxied and soldered in, but I'm waiting for the optics to come in). Other people seem happy with just the CW and Royal. The corals I have are doing fine with just the CW and Royal, so it is a human eye thing, not a coral thing that is driving me to add more LEDs.

 

[giulianom]

I'm thinking that I might be able to do away with the 7.28" wide heatsink, and only use the 10" one.

It would give me 54 pods of 3 LEDs, or a total of 162 LEDs.. on top of a 150G tank.