DIY LED lighting

[evilc66]

If you are talking about Lumileds (Luxeon), which you didn't make quite clear in your post, then yes thats right. Problem is that the K2 LEDs they are using are a few years behind the curve. The new K2s with TFCC are much better, but are still hard to find because of the recent recall. There are other manufacturers that are equally as good, if not better than the performance of the K2 LEDs, such as Cree, Seoul Semi, Edison, Osram and others.

 

AquaIlluminations uses SSC LEDs if I remember correctly (P3/P4?), and others here have used Cree's quite a bit for their DIY projects. I'm using the Luxeon Rebels, but they have the same supply issues as the K2 TFCC.

 

My advice right now if you are looking to do this is to steer clear of the old K2's. They are thermaly and optically inefficient compared to the new stuff, and the price is around the same for some models if you look hard enough. Oh, and if you don't see one of the manufacturer name I listed above on the LED, I wouldn't guarantee it's performance at all.

[coolwaters]

hey again people.

has anyone tried out the new p7 c-bins?

i got 3 regulators (cant find them atm...) and each gives out about 755mA so if i wire them in parallel i'll get almost 2.3amps. as soon as i get enough money again and time... i'll use that and maybe 4 blue LEDs.

hopefully the D-bin will come out by then. or even E-bins...

[Zombo]

Well, with evilc66's assistance, I'm starting to piece together my LED retrofit for the FrankenWave9. So far, I'm going with 5 x Cree XR-E Q5's and 8 x Cree XR Blues, driven by two 1000ma BuckPucks. We're still on the hunt for a cost-effective heatsink that will retro into the existing hood. I know this is gonna be a pricey setup, but in the long haul, I'm going to be much happier with the results than had I gone with a Sunpod or stuffing 96W of PC's in the hood.

[coolwaters]

have you thought about using high performance cpu heatsink and bolting them down to the heatsink?

that might be overkill...

 

just get a nice size aluminum heatsink and a good big fan to cool it off.

copper oxidizes too fast. and worst of all its so close to saltwater.

 

im planning to use a P7 led along with some blues on a less then 5g tank. im going to be using a intel stock heatsink. it should do the job

[coolwaters]

hey guys im going to be back to LED reefing soon. maybe next month or 2.

hopefully the D-bin P7 comes out by then. but im liking the blueish tint on the c-bins p7. i'll probably add 2 or 3 Blue LEDs to make it bluer.

 

also adding a adjustable lens and light diffusers. its going to be crazy so just w8 up =p

[coolwaters]

hey thats a pretty cool looking heatsink

http://www.led-tech.de/en/High-Power-Suppl...89_106_114.html

 

anyways heres a pic of the heatsink that i might use for the P7. but might use something else if i cant get some Blue LEDs to fit.

 

i was thinking about mounting a copper base but i'll rust/oxidize too fast.

 

i'll probably just use another aluminum plate.

[itz216]

Anybody tried this style ...pin fin heatsink?

Pin Fin Heatsink

[evilc66]

Would work fine for individual 3W LEDs, but they don't make them very big. Plug they will be harder to get and somewhat expensive. PC heatsinks are a very cheap and easy way to get the job done.

[itz216]

Opinions ...what determines the efficiency of a heatsink ...material then shape then mass ( thick to thin ...pulling heat away)?

 

I might be drilling down too far ...just curious, and it might help determine the "best" material and shape to search for ...or make.

 

IMO, I think price is relative ...if you are counting on this thing protecting $50, $100, $200 or more worth of LEDs plus the time it took to buy, take delivery and assemble, then who cares if it cost $40 or $50? Buy your LEDs in bulk and you can save that much.

[Zombo]

Buy your LEDs in bulk and you can save that much.

 

Bulk prices LEDs, from what I'm seeing, are not as efficient at providing the PAR/Lumen values you'd need to effectively light a reef, hence the need for 50+ LED arrays to do the same as a <15 LED array using quality high-powered LEDs.

[itz216]

...clarify ...bulk as in "quantity" discount (not quality) ...buy 10+ or 20+ or 30+ and some sellers drop the price per unit.

 

DealExtreme.com sells the Cree XR-E Q5's for $6.98 ea., but if you buy 10 or more the price drops to $5.91 ea.

 

Considering most projects will demand 10+ ( my est. is a 55G would need 100+), there's $$$ to be saved by buying them at a quantity discount ( bulk rate).

[evilc66]

The two major factors for a heatsink is mass and surface area. You want a base that is thicker (more mass) to help wick the heat away from the heat source. The thicker the base, the longer it will take to saturate. Surface area is probably more important than the mass of the heatsink. Every additional square inch of area that is exposed to the air creates that much more ability to reject the heat.

 

Having a ton of surface area doesn't always make it effective for a certain task. Take for example the heatsink you linked to. With the fan mounted to the top like is shown in some pictures, there is more air flow contact around the circumference of the pin, which is a plus, but there is a large dead spot right under the center of the fan, which is probably where the majority of the thermal load is going to be.

 

Now put the fan to the side. You elliminate the dead spot, but now you have reduced the efficiency of the air flow going through the heatsink. The air hits the first set of pins and creates turbulence (which in the right circumstances is what you want) and slows the air velocity down quite a bit, reducing the effectiveness of the airflow and the heatsink.

 

Sorry if I went a little too far into things there. Heatsinks can be a tricky thing to pick out. Bigger doesn't always mean better. High fin count can be good. But if high fin count forces small fin seperation, it reduces effectiveness at low/no air speed.

[itz216]

Thx.

Thoughts on a heat sink based on the pin fin, but using a 1/8" sheet of copper as the base employing wires with the ends pounded flat ( like a canoe paddle) instead of pins?

 

Thought ...mass for absorption and less density of pins and ever thinner material for fast heat transfer. Would need fine tuning of paddle angle for optimal airflow across heatsink.

 

Easy to fabricate ...might be effective for small and large applications - albeit time consuming for multiple feet of surface.

 

[evilc66]

Interesting idea. You will find that making that by hand to be quite difficult. The pins on that type of heatsink are an interference fit. Meaning that the pin is slightly bigger than the hole and it is pressed in. It will be difficult to do with pins that thin by hand.

 

I think you will also find that there are many heatsink available for very little cost that will perform adequately. Don't get me worng, I'm all for DIY. But there is a limit

[itz216]

My lighting "hood", a 9" dia. copper dome, will basically be enclosed, so I'm trying to think of a really simple and highly efficient way to get the heat transfered to the air inside this dome. Then I can use a tiny fan to push the hot air out through a simple exhaust port ( read: hole) while cooler air is drawn in through strategically drilled vent holes.

 

Something tiny like this ...small ( 25mm x 25mm x 10mm) ...quiet ( rated @ 20 dB)

Sunon Fan

 

Or this may be the solution ...if the technology matures to consumer level - due out 2009.

Micro fan

[evilc66]

Try and go with as big of a fan as you can fit. That dinkey little fan @ 20db only pushes 1.2cfm. This 80mm fan pushes 27cfm @ 21db. It also has a greater chance of lasting longer. I've seen lots of those tiny fans start making noise and fairing withing a pretty short period of time in comparison to larger fans. Plus, the more air you can move over the heatsink, the more effective the cooling will be.

 

What kind of array are you trying to set up?

[itz216]

What kind of array are you trying to set up?

 

I'm thinking (8, maybe 9) of the Cree's you suggested ( XR-E Q5). (4 or 5) cool white and (4) royal blue ...running at 700 or better yet 1000mA. 5"x5" copper heatsink, TBD. LEDs set up in three rows ... 3/2/3 or 3/3/3 grid. LEDs will be about 2-3" from the surface so I may need some optics. (8 or 9 ) x 3w over 5G ( 20" deep x 9" dia.) should give me enough light to grow some SPS along with the zoas/palys, GSP and shrooms/ricordea I have now.

 

Since this tank is so small, it's best viewed close. So I didn't want to put in a big loud fan with a big vent, but I defer to your experience - and the dB rating and 27 cfm on your 80mm makes it a real possibility, thx ; ) How about several tiny fans? Maybe 1 in and 1 out to generate good air replacement and turbulence? Redundancy brings safety ...

 

How about 18cfm and 16 dB ...fan

[Zombo]

With a 5:4 ratio of Q5's to Blues, you'll have less of that visually appealing "blue" tint to your reef, but more white. The Q5's, AFAIK will wash out the blues pretty easy -- that's why I'm going with a 5:8 ratio Q5:Blue on my array...just some food for thought.

[evilc66]

It may not look too bad. Really depends on what itz216 really wants it to look like.

 

Itz216, I'm starting to remember what we talked about. I agree that redundency might not be a bad idea. If two fans were used, I would say both blowing in would be preferable.

 

Normally I would say that with the array being so close to the water you wouldn't need optics, but with a 20" depth it could help quite a bit. If you are to use optics, I would try to raise the array a little higher if possible to get more light spread at the higher portions of the tank. Then again, it might not be too bad without them considering the tight 90deg viewing angle of the XR-Es.

 

I think out of politeness for Coolwaters, if this project goes much further, you should start your own thread.

[itz216]

Agreed.

 

Thx Coolwaters for starting this thread ...and Evilc66 for supporting tech stuff.

 

...look forward to seeing some DIY LED lighting.

[Weetabix7]

[coolwaters]

its been a while since i done this but i like to think everyone thats keeping this thread alive until i get back to reefing.

 

im aiming for clams and rics.

 

check this site if you want to know what makes heatsinks efficient.

http://www.frostytech.com/top5heatsinks.cfm

but keep in mind the heatsinks there are for 125w+ CPUs so a mere 10w of leds would be overkill.

 

you can tell the fins are razer thin (i got a Tuniq for my PC and it can cut you up pretty bad) also heatpipes for LEDs isnt needed unless is one of those 100w+ LEDs.

 

im w8ing for the D-bin P7 LEDs because i was planning to get one and maybe 2 blue LEDs.

that should give me a 10k look.

 

having single LEDs all wired together is just too much work for me now...

 

i spent a lot on LEDs up to now and i only wished i did my research before i bought anything.

 

also a fan is a must. like wat Evilc66 said heatsinks will get heat soaked over time and will burn out LEDs.

[evilc66]

also a fan is a must. like wat Evilc66 said heatsinks will get heat soaked over time and will burn out LEDs.

 

Fans are not a must. If the heatsink is properly design/selected, the fan just aids in the cooling process. Ideally you want a heatsink that can deal with the heat load without using a fan incase of failure. Most of the time we have to make compromises on that becasue the right heatsink is not always available. Easy insurance is to go big (mass wise, not number of fins)

[coolwaters]

PC fans "should" last just as long was the LEDs.

 

i noticed on my custom heatsink (basically 12 chip set heatsinks mounted on 2 aluminum bars) wasn't enough for 10w LEDs and that sucker was huge...

 

but it was fine for the first 15 mins until it got heat soaked. a small 50mm PC fan kept that at a chill temp.

 

if i remember correctly your heatsink was just as big as the tank? XD im just messin with u

 

im really looking forward to the P7 LEDs just wish my rebates from my computer came faster....

i got $30 back so far. about 140 more to go =p

[coolwaters]

first post updated....

 

dam just noticed that the lens is glass...so its going to be a little tricky to drill a cavity for the LED.