DIY LEDs - The write-up

[Yossarian99]

I just used a small instant-read cooking thermometer I attached to the heatsink with the aid of some heatsink compound and tape. Probably not the most reliable method, but the numbers still gave a good idea.

I'm now using an electronic temperature probe just measuring the air temperature in the top part of the hood. It'e probably not very reliable in this configuration, but the lead right now is too short to bring it right to the heatsink.

 

[shikhyung]

soundwave, the buckpuck could handle 2 of 6 string of LED, but from your part list, look like you wired 1 for each 6 string. Is there a reason? Thanks.

 

[Soundwave]

I was informed that 6 was the recommended max for each puck. Where did you see that they can do two strings? If that is possible, I may add more LEDs to my setup.

Because of the new lighting, I've found myself acquiring more and more sps to test the coloration and growth. So far, so good.

 

[ReefEnabler]

What's the Vf of your LEDs again? Each puck has 32v output, and its recommended to leave 2v buffer, meaning 30 is really the most Vf you want.... I thought you were using just under 24 volts per buck???

 

[der_wille_zur_macht]

<a href=showthread.php?s=&postid=14837720#post14837720 target=_blank>Originally posted</a> by ReefEnabler
I look forward to seeing what you decide for that tank. Please be sure to keep us updated!

Certainly will, but construction is probably a year or two off so don't hold your breath.

(hopefully by then, XR-E's are cheaper!)

 

[james3370]

uuuugh, now i keep looking at my biocube 8 thinking "i can get a spare hood from nanotuners.com for $60. i have several old laptop power supplies laying around, i wonder how many LEDs i'll need....."

 

[dogstar74]

I was asked about the driver that I used. I used it for the simplicity of just plugging it in without another power source like a PC power supply. This was great to simplify the 6 LED strand that I used. However, that would pose huge problems in a large array, as you can only drive 6 LEDs with the Xitanium driver, and you would need a new power cord for every driver. Therefore you'd need several power strips just to plug the light into.

So in conclusion, the buckpucks could all be wired to the power source you choose so long as the voltage and current requirements are met. Thus soundwave's construct is more conducive to any lighting scheme not intended for a nano requiring only 6 LEDs.

Cheers
Aaron

 

[Yossarian99]

Dogstar,

You could probably wire the inputs of all the line drivers into a single power cord (using a terminal strip, or a suitable wire connector). The only limitation is not to exceed the rated current draw on the suppling power cord/circuit.

Still, I find the line drivers to be much more expensive, so in a larger project (like mine - 48 LEDs), I chose a DC power supply and DC voltage drivers (buckpucks).

 

[fernandokng]

Just to give you guys some feedback on the last week.

After further discussion, I was able to get LEDsupply to provide me my missing parts. I'm happy and ready to start on my project, though it shouldn't have taken this long.

I was furious at them at first, but they came through the second time around. So now, I'm happier customer

Can't wait to get started! I just have to make sure all of LEDs work now. hehe.

Btw, do you guys use any shield to block the leds from water splashes and salt creep?

<a href=showthread.php?s=&postid=14819036#post14819036 target=_blank>Originally posted</a> by fernandokng
I doubt the delivery guy opened anything. I think the worst feeling, other than losing the money, is being called a liar. You pay for something, and when you don't get it's bad enough. But then be called a liar when you're trying to sort things out, and get blamed for things you clearly did not do is just horrific.

He's like "I know people like you, and you're lying". I'm not an idiot (or blind), and it's pretty easy to tell the box was empty with the exception of the optics. Telling me to go check the box again and again doesn't help me much. And then he think he's trying to do me a favor by offering to charge me again, but only at 50%. I never flat about blamed him that he screwed up, and only said that there might have been some mix up in the process and waited patiently. Of course though, he did not hesitate to call me a liar.

For those people who have gotten their products, I'm glad you had a great experience. Based on my experience though, if you have any issues after your order, you can kiss your money good bye. Their kind of service can be summarized by reading their "no return policy", and I should have been more skeptical. I couldn't have presented my case anymore honestly than I had, and I don't hope this doesn't happen to the other reefers.

I also told him to visit ReefCentral, to see that I'm actually not a scam artist, and I was doing this legitimately for my tank. He said something along the lines of "I don't care about what you're doing for your reef tank, etc."

Ironically, today, I got my other LEDs from DealExtreme.com, which is based out of Hong Kong. Who would have imagined I'd be ripped off by a US company instead of an HK one. Crazy huh. Now I have to find another place to get the buckpucks, the blue LEDs, and the optic holders.

Good luck to everyone on their future LED purchases.

 

[Yossarian99]

Fernando,

Glad to hear you got that mess sorted out. It's good when a business recognizes the value of keeping a customer happy

On my build, I haven't yet installed a splash shield, but I'm hoping to get some acrylic over the weekend to serve this purpose. It's going to mean I have to cut ventilation holes for the fan intakes now, but that's not a big deal.

I don't think I mentioned in my previous posts, but I just slapped the stuff into an old All-Glass canopy ('All-Glass' is the brand name, not the construction - it's just plastic).

In any case, even without splashes, exposure to the salt air can rapidly corrode some components, so protection is very important.

 

[shikhyung]

Actually, the more strings you drive, the less current drive the LEDs. Ignore my question. Thanks.

 

[dogstar74]

Fernando,

That's wonderful news.

 

[Soundwave]

I keep a plexi shield over the entire bottom of the fixture. The way mine turned out, the fans suck air in and blow air out the sides of the enclosure. There are also holes in the far ends of the plexi so air is allowed to flow over the face of the LEDs to further aid in cooling.

 

[therman]

Has anyone tried to pop an LED off that was attached with the Arctic Silver thermal epoxy?

I'm considering a larger LED build with around 40 LEDs and considering the price difference I may go with the super cheap ones from ebay. However if they are junk or go bad, I want to be able to replace them down the road with higher quality LEDs. Wondering if "popping" them off is actually a possibility, even if it does do some damage to the LED being "popped"

Thanks!

 

[james3370]

short of a hammer & chisel, you won't get it off the epoxy LOL ....for that reason, i used regular screws & nylon washers...as seen above

the drill & tap combo from lowes, HD, or sears works great. just be sure to be-durr the hole pretty good first using a countersink. makes starting the tap straighter much easier (worked 10 years as a machinist). also, lubricate the tap well (i like wd-40) & be sure to occasionally reverse direction about 1/4 of a turn at least once every turn of the tap. this keeps the chips in the hole from getting too long & getting between the tap threads....which will break it

 

[therman]

I'm fine with a hammer and chisel if it's a bad LED Did you use some sort of thermal grease between your LEDs and the heatsink? I had some laying around from when I did thermoelectric stuff, and used it on my other LED light build.

 

[Yossarian99]

I, too, used screws to mount the LEDs, mainly so I could replace bad ones, or add blues if I didn't like the all-white configuration. Definitely use heat sink compound - it increases the efficiency of heat transfer to the heatsink. Myself, I just used a basic silicon grease compound I bought from the electronics store I bought my supplies from.

When using screws, make sure you get the smallest you can. I got #4 stainless steel, but I think #2s would have worked better (but I couldn't find any). Mine were 1/2" long - the shortest I could find. 3/8" would have been better. They were self-tapping, so I didn't have to tap all the holes - made it a lot easier. But being stainless steel, the heads broke off if I used too much force to screw them in. In the end, I may have preferred to tap them, but it all worked out in the end.

I'm using nylon washers to prevent electrical contact between the screws and the terminal contacts on the star boards. I was a bit concerned with using nylon, as I know it can get brittle over time. So it's something I will keep an eye on.

 

[dogstar74]

Here's some real world data to crunch, albeit not very scientific.

Here's what the fixture looks like over the tank. I think it's stunning. I am kinda digging the alien abduction type light column in the middle of the tank. And the shimmer is something that I really missed. The colors of the GSP are popping out at me, and my Rhodactis are faintly orange again just like when and why I bought them.

Here's the kickker,

Do you remember that I thought this heat sink was WAYYYY overkill for 6 LEDs? Well here's some data with a meat thermometer placed deep within the vanes of the HS.

And for us americans:

I can't believe how hot the thing is getting. So I will probably go ahead and mount a fan to it. It'll be a 120V AC fan and I'll just splice it into the supply cord rather than have it run off the same circuit as the LEDs.

Cheers!
Aaron

 

[kcress]

Thanks for that demo Aaron! 120F isn't hot for LEDs but of course your finger would probably disagree. LOL

BTW I like the alien column thing too. Some serious spot lighting might actually further a feeling of a larger tank. You know the light filtering down thru the massive reef above, etc., etc.

 

[Soundwave]

I found that with fans, mine hovers around 80-85 degrees. USE EM.