DIY LEDs - The write-up

[ReefEnabler]

Hey all....need some advice here.

I finished up the first of my 2 fixtures to go over my 46 bow last night. Of course I had to hold it over the tank to see what it would look like. Here is the weird part, it's providing blue and white disco ball like effect over the tank. I don't have heavy surface agitation, but enough that it shimmers. I'm at a loss here why it's doing this so bad. My fish will be trippin if I leave it over the tank. No video yet, and not sure it would even capture the effect.

I'm planning for 34 LED's total, 17 per half. 9 Blue, 8 White.

Any thoughts on what could be causing this? Is it too few LED's? Spacing too far apart? I'm looking for some direction if anyone has experienced this before.


Scott

10"x10" HeatsinkUSA.com heatsink
http://i267.photobucket.com

what hight, and optics?[/QUOTE]

Your video looks like normal shimmer to me. I can tell the surface agitation is minimal because of the very high frequency way the shimmer is forming. If you put a powerhead up near the waterline to get some more rolling surface action, chances are the shimmer will be more "macro" and dramatic, and less like little balls dancing around eachother.... either way you will still get flashes of blue/yellow but that's pretty much a desirable effect to most of us.

Optics can actually make the shimmer less crisp, since they are increasing the size of the bright spot as seen from the water. With no optics you have a teeny tiny bright spot. With the Cree or Carclo optics you then have a bright spot that is almost an inch wide, so it does make the shimmer less sharp, but not by much.

 

[madmike]

Sorry if this has already been answered a thousand times but how far can the meanwell driver be away from the first LED in the string. I see most people mount them with the fixture, but I want to add 12 leds along a aluminum channel to the back of my ATI sunpower fixture, so I want to hide as much as possible. The driver could be as far as 12 feet away from the first LED, would this be ok?

Also, what are the current "best" LEDs for both the whites and blues. The white XPG and the XRE royal blue?

Thanks!

 

[MerDoX]

Stu,

Your comparision shots are amazing. This is what LED non-believers should look at. I think the LED side is more evenly spread out and brighter also. I agree that you need to add some blues or exchange some whites for blues to get the desired Kelvin level. But LEDs 100W (36 x 4v(round up) x 700mA) = MH 400W?!?!!! WoW! You are not even running LEDs at their max of 1A.

Please describe your LED arrangements (spacing, optics, heights off the water) and tank size. Thanks.

 

[Neogenocide]

ReefEnabler....

Thanks for the feedback. I played with them a little tonight after they ran through a complete light cycle. I am liking them more and more. I plan on forging ahead and finish building the second of the two fixtures. After I get them complete, I'll have to play more with height, optics, and flow to get the look I want.

Thanks again everyone for this great thread and feedback!!

Scott

 

[100%hydrophylic]

i guess this is the place to ask LED questions? well my bad on making a new thread lol.

i have a AC to DC converter. 12VDC 1.5A

will that guy plug into this guy

http://www.nanotuners.com/product_in...roducts_id=617

and power 6 leds?

i want to get my supplies from nanotuners, so its going to be 3 of the blue LEDs and 3 of the white.

 

[dnahas]

The driver could be as far as 12 feet away from the first LED, would this be ok?
Thanks!

Yes, make sure you use a large enough gauge for the current and distance.

The white XPG and the XRE royal blue?

Thanks!

Yes.

 

[madmike]

Thanks dnahas!

 

[kcress]

Whoa, whoa!

Who said twelve feet is OK??! None of the driver companies will say that. They normally quote a few feet - like 2. Perhaps 6 feet might work too. 12 feet c o u l d work. It could also not work. It could also blow out all your LEDs or the driver.

You should strive to include the driver into the fixture. If you can't, keep the cords as short as you can.

Until someone does some long term testing on a couple of different drivers, (same exact model), you can't assume a long set of leads will be problem free.

 

[madmike]

hmmm.... that sucks.... I guess I'll have to be the guinea pig then because a meanwell driver mounted on my ATI fixtures would definitely be an an eyesore

 

[The Grim Reefer]

I would just set up a sting with 12 feet of wire or whatever you need and test fly it before you go go through the hassle of getting everything in the fixture. At least if you do toast everything you wont have to start over from scratch.

 

[der_wille_zur_macht]

Woah I take a weekend offline and three pages go by. :lol:

I'm sure this has already been addressed, but:

It's as if I'm seeing blue shimmer and white shimmer at the same time.......not sure but I'm not really liking what I'm seeing so far.

Scott

I see that often on certain LED rigs. I'm kind of surprised it isn't talked about more frequently. In my head I call it "color separation" - not sure if it's an accurate term or not but that's what I use. Factors that seem to make it more pronounced:

1) Spacing between the LEDs. I.e. if they're not mixed well.
2) Overall LED count. If you've only got 6 LEDs - 3 white and 3 blue - vs 36 of each, for instance - it's more pronounced.
3) Optic choice. Tighter optics = more laminar light = this effect is a little more pronounced.

Ways you can combat this, if it really annoys you - get a "diffuse" or "frosted" lens as wide as you can find, or make your own from a piece of frosted lens from some other source, and put it on a small number of your LEDs (like, 10% or less). This will create a diffuse "backdrop" light that should cut some of the color separation. I'd try these diffuser lenses on only whites, only blues, a mix of both, etc. until it looks right to you.

 

[TheFishMan65]

Wow, go away for a weekend and I have a lot of reading. However, I also reread some. So...

Sorry Stu I missed your post. I need to read about 'steradians', been a while since geometry. You said:

So for a point source the inverse square law works, but for an emitter that emits over 2PI steradians, it should be = (Inverse Square LAW) / 2 for an emitter that emits all light over 1/2 sphere (hemisphere).

This seems to support that LEDs are going to have 1/4 of the light on a square inch each time the radius doubles. It just states that the starting amount of light will be twice a the amount of a source sending it light out in all directions.

I think maybe we are discussing semantics. So help me out here.
Point Source - I think your definition (and maybe the correct one) is a light source the sends light in all direction equally. I was using a light source that sends light in a given cone equally (not completely true of an LED, but close).
Do you agree that if LEDs had a even spread of light across there angle of spread that each time the distance doubled the lumens/square inch would be quartered.

 

[Santoki]

I would like to see aquariums pics with led lighting.
Prefereable from this thread.
Thanks

24 XR-E (Q4) per array. 3 arrays total. 1:1 blue/white ratio. All emitters driven @ 700mA.
Emitter spacing ≈1.5" center to center. Active cooling.
40˚ optics
4' 75g.

12 XR-E (Q5) per arrray. 3 arrays total. 1:1 blue/white ratio. 700mA.
Emitter spacing ≈3 per foot. No active cooling.
80˚ and 60˚ optics
30" 70g cube.

Closer shot to show color of 1:1 ratio:

And last, a MH comparison pic.

36 XR-E (Q5) per array. 1 array total. 1:1 ratio. 700mA.
Emitter spacing ≈1.5" center to center. Active cooling.
60˚ optics
6' 300g

The LED unit is flanked by 2 newly replaced 250w XM 15K HQI bulbs.
Max coverage is not demonstrated in this pic, since old MH pendent mounting position was used. Final mounting position to be 5" further back.

For some reason the actual intensity difference does not show in the pics. The extra intensity just looks more washed out on camera...

-R

 

[rickb]

Just put together my setup, but when I dont put any power to the meanwell I still see a few of the LED powering up just a small bit.

 

[der_wille_zur_macht]

You are correct on the efficiency. The Carclo 10mm optic, 10414, has an efficiency of only 80% while others are up closer to 90%. The angle of the 10414 is actually 36.7 degrees according to Carclo's specs. The Cutter web site lists it incorrectly.

I used 150 of these 10414 Carclo optics on the 10mm square boards from Cutter. The little pegs make them incredibly easy to mount and I was very pleased with the beam I got. My LEDs (XP-G and XP-E) are about 15 inches from the water surface, 30" deep tank. The only issue I had with the 10mm board was they are a bit more difficult to solder given the smaller pads and the fact that the tip of your solder gun up very close to the LED. I soldered some 20mm stars and they are childsplay compared to soldering the 10mm squares.

Anyone else used this 10414 Carlco 10mm square optic?

Seems like the "best" choice for the XP-G at the moment. It's not quite as efficient as it could be, and you need to use it with a square MCPCB, but it's at least cheap and reasonbly wide.

 

[der_wille_zur_macht]

For people who haven't seen it, here's the Carlco optic brochure for Cree xlamps. It's pretty buried on their website so I figured I'd post here:

http://carclo-optics.co.uk/catalog/documents/Cree-01-10.pdf

 

[skippyreef]

Thanks for posting the brochure.

I also noticed that some of the rigs are not using traditional heat sinks. Looks like some people are using aluminum rods, channels, flat pieces...ect.

 

[skippyreef]

24 XR-E (Q4) per array. 3 arrays total. 1:1 blue/white ratio. All emitters driven @ 700mA.
Emitter spacing ≈1.5" center to center. Active cooling.
40˚ optics
4' 75g.

12 XR-E (Q5) per arrray. 3 arrays total. 1:1 blue/white ratio. 700mA.
Emitter spacing ≈3 per foot. No active cooling.
80˚ and 60˚ optics
30" 70g cube.

Closer shot to show color of 1:1 ratio:

And last, a MH comparison pic.

36 XR-E (Q5) per array. 1 array total. 1:1 ratio. 700mA.
Emitter spacing ≈1.5" center to center. Active cooling.
60˚ optics
6' 300g

The LED unit is flanked by 2 newly replaced 250w XM 15K HQI bulbs.
Max coverage is not demonstrated in this pic, since old MH pendent mounting position was used. Final mounting position to be 5" further back.

For some reason the actual intensity difference does not show in the pics. The extra intensity just looks more washed out on camera...

-R

Interested in what type of rail you used for the pendents? BTW thanks for all the information and inspiration.

 

[Skeptic_07]

Whats the better option (talking about heatsinks) for doing LED strips of Royal Blues just to supplement T5? I want 12" modules.
Using aluminum "L" or angular channel
1"x1" or 1"x1/2" squared aluminum tube
getting any profile heatsink from heatsinkusa (lets say 8.4" x 12" and have it cut at 1" wide) final pieces will be 1"x12"

OR just getting 8.4 profile x 1" which is cheaper $2.25 but the fins run the short side

And last, 1/8" thick aluminum sheet (again 1"x12")

Thanks!

4 LEDs in each 1" x 12" ran by a meanwell LPC35-700 (3 modules in each driver) guess they run @ 700mA

you could probably do that on 12" of flat aluminum if you wanted to. I did 4 RB XRE on a 700ma buckpuck mounted on 8" of L channel and ran them continuously for a couple months, no fans. it got warm, but never really hot. I'd use L channel again because it was easy to mount and CHEAP!

 

[Santoki]

Skippy,
if you are referring to the first pic, those pendents are mounted to trolleys which fit inside the 1 5/8 x 1 5/8 channels. I had played around with the idea of light movers originally and figured the trolleys would make it easier to move the pendents around before deciding on a permanent position.
-R