JB`s LED Build Thread

I'm using thermal adhesive. It's less work and it works perfectly fine.

The lenses I use have adhesive tape on the back, so they come with their own adhesive. I order a few extra in case have problems with getting one to stick.

 

Ok, If anyone is interested, I'm going to have a little DIY LED workshop for club members next Sunday (May 22nd) starting at Noon. It will probably last several hours (maybe until 4 or 5). We won't be able to complete an entire fixture, but I will try and hit all of the main points.

I'll be posting about this in another thread a bit later.

If you would like to attend, please RSVP.

Thanks

-JB

 

A few thoughts:

1) I would go with 2 channels rather than 3. I can tell you from experience that the added complexity of a 3rd channel doesn't really buy you anything. I'm going with a 2 channel design on the lights I'm building now for my display tank.

2) I can't see any real value in using both XM-L and XP-G. The XM-L's are 20% more efficient than the same current than XP-G's but they are also more expensive. I used XM-L's on my frag tank light and I'm using XP-G's in my display tank fixtures. I decided to go with the XP-G's because they are cheaper and good optics are readily available for them (at the time I ordered, no optics were available for the XM-L).

3) I used 80 degree optics for my display tank lights. The added spread should help reduce shadowing. Also, if you read ReefLedLights.com's article on how to pick optics, they say that the 70 degrees actually have more par than the 60's, so the 80's can't be too bad.

-JB

 

My display tank is a 6' 125. I will have 3 fixtures each with 36 LED's. 24 Royal Blue XP-E and 12 Cool White XP-G per fixture.

For the drivers, if you don't care about dimming, there are a number of drivers out there that will drive a bunch of strands. If you want dimming, the 60-48D is the best bet. It can drive several strings, but the more strings you put in parallel, the lower current you will have per string. I'm running all 24 blues on 1 driver, and I'm getting about 800mA per series.

-JB

 

That sucks. I've noticed a few very minor issues with the LED's from there, but nothing major like that. Hopefully you won't have to wait for the next group buy to get replacements...

 

Here is a basic description of Series vs Parallel Circuits:
http://edwardcho-sph3u.blogspot.com/2010/09/what-is-difference-between-parallel.html
LEDReefLights.com has a nice page on wiring that shows a simple "series" configuration as well as some parallel configurations:
http://reefledlights.com/wiring-diagrams/
-JB

 

Yes, you can run 24 XP-E on a single 60-48D driver as long as they are in 2 series of 12 ran in parallel (I went in to more detail in your build thread).

And as a matter of fact, yes, I do have a FTS shot now. I just finished installing my LED's in my display tank tonight and I'm going to be posting the pics in a sec.

-JB

 

Ok, so it took me all night, but I've got my LED's installed in my display tank.   The verdict:  LOVE THEM.    There is a very slight amount of banding towards the top of the tank, but it's not that noticeable unless you're looking for it.   The inside of the tank is definitely brighter, but there is less "light splash" outside of the tank than I had with my metal halides.   I believe that this is because the optics do a much better job of keeping of focusing the majority of the light inside the tank.
Here's what the tank looked like with my old lighting: 3 x Phoenix 14K Metal Halide (250W)
/Portals/0/activeforums_Attach/FTS-1.jpg
Now here it is with the LED's installed and running at 100% power.  The overall color is VERY close to the 14K Phoenix look (which I love)
/Portals/0/activeforums_Attach/FTS-3.jpg
Here's all of the LED's running at 10% power (the lowest the drivers will go).   Looks great, even at low power, but definitely not as bright.
/Portals/0/activeforums_Attach/FTS-2.jpg
Here's just the Royal Blue XP-E's running at full power...   Talk about colors that POP! (my camera doesn't do it justice at all).
/Portals/0/activeforums_Attach/FTS-4.jpg
Now the Royal Blue's at low power
/Portals/0/activeforums_Attach/FTS-7.jpg
Cool White XP-G's running at full power
/Portals/0/activeforums_Attach/FTS-5.jpg
Cool white at low power
/Portals/0/activeforums_Attach/FTS-6.jpg

 

I'm not sure that I believe that LED's are all that powerful.... There are probably a lot of factors involved (like the type of optics, etc). In any case, I'll be starting low and ramping up. I'll probably start at about 50% and ramp up to 75% over about a month.

 

Assuming you have a center brace, I'd go with 2 48 LED fixtures, each with 32 Royal Blue (XP-E), and 16 Cool White (XP-G or XM-L).   I'd put them on a 24" x 8.5" heat sink with 2" spacing between the LEDS (4 x 12 grid).   For optics, I'd go with 70 or 80 degree optics.   The drivers are a little more tricky with this configuration.   You could get away with 2 or 3 drivers per fixture, but I'd probably use 4 per fixture.  2 for the blues and 2 for the whites.   I would divide the LED's into series of 8.   For the blues, I would run 2 series of LED's in parallel per driver.   For the whites, I'd run a single series of 8 for each driver.   The reason for this is that the XP-G/XM-L can take a lot more current, and running them in parallel knocks down the current quite a bit.    This is only one of many possible configurations.   If you don't care about dimming, there are other options that would require fewer drivers.
As Andy said, this will be expensive (probably around $500 per fixture) but that will be offset by a lower cost of ownership (no bulb replacements, lower electric bill, etc).