coolwaters Posted January 8, 2008 Author Share Posted January 8, 2008 ok i took apart my tank again just to clean it and make improvements. ok so far the heatsink is 7/8" tall so i can probably make the hood less then 1 1/2" tall it weights like 2 lbs... i may have been better off with 2 copper heatsinks...but w/e im happy so far. the space where my LEDs are located will be about 1/2" so overall im predicating the hood to be no more then 1 1/2" (1/2" more then i want but we never get what we want...) Link to comment
Shoot Me_I Explode Posted January 10, 2008 Share Posted January 10, 2008 Could someone be so kind to give me a link to the 3w blue LED's with the star board on that site. I've looked all over the site and can only find the white ones coolwaters links to on page one. Also do you think 20 led's are enough to light a 10gallon tank to support a sps and clams? Link to comment
Hans Dorn Posted January 10, 2008 Share Posted January 10, 2008 Hi Shoot, I guess you're looking for these: Blue Cree XR These are rated ca. 16lm @ 350mA BTW. You might want to look out for the newer XR-E blue. They're rated ca. 40lm @ 350mA. Even at twice the price, you'd get more bang for the buck Regards Hans P.S: Decent blue LEDs are hard to find though. I paid a small fortune for mine.... Edit: Another source: Dealextreme Cheaper if you order more than a couple of them. Link to comment
coolwaters Posted January 10, 2008 Author Share Posted January 10, 2008 yeah it is cheaper at dealsextreme if u buy more then 3+ just have to remember to type in "bulkrate" || To enable volume discounts on this site, use coupon code: BULKRATE during checkout || anyways 20 leds on a standard 10g AGA should be fine since thats about 60w of pure light. u just have to put more white LEDs then Blue. and place it so the light is denser. btw make sure u understand how to power the LEDs http://www.candlepowerforums.com/vb/showthread.php?t=175615 cuz if u dont they wont last more then a few months.... btw the blue LEDs im using is pretty outdated but still bright. im packing my LEDs closely and using light diffusers. im just stuck improving my DIY tank... Link to comment
coolwaters Posted January 10, 2008 Author Share Posted January 10, 2008 i just noticed luxeon is selling thos new TFFC LEDs for K2. now its 200lumens. but thats still 42lumens per watt....Seoul is in the 60lumens. not sure about cree tho. my total hearsink area is like 8" X 3" so i should be able to get the 15+ LEDs i want. im aiming at 18 LEDs so 54watts of pure light should be great. also most of it is white. the sump is going to be one red/blue/white each will probably be running at a total of 1 watt not bad for a refuge of half a gallon. if it doesnt get hot i'll leave it on 24/7. i checked on ebay to see if i could get a nice copper sheet. but im happy what i got so far. if anyone wants to do this project with a lot of LEDs i recommend getting a nice at least 1/8" thick copper sheet and aluminum heatsinks on top. cant w8 to put mine together. still have to wait like 2 more weeks for my new LEDs. but i'll just take apart my other arrays so i can start on it sooner. Link to comment
Hans Dorn Posted January 10, 2008 Share Posted January 10, 2008 Im using 1" square aluminum tubing as a heatsink. I glued the LEDs to it with thermal epoxy, and let a slow fan blow along the top. The LEDs only get slightly warm at 350mA. I don't plan on driving them harder - yet Regards Hans Link to comment
coolwaters Posted January 10, 2008 Author Share Posted January 10, 2008 i really think u should get something with fins. like an real heatsink. but if it works for you then great. can someone help me find a cheap low profile water cooling system? XD Link to comment
evilc66 Posted January 10, 2008 Share Posted January 10, 2008 square tube will work fine. Heatsinking is all about mass and surface area. I had thought about doing similar for when/if I retro my BC14, but I was going to use C channel. Link to comment
shagrat Posted January 10, 2008 Share Posted January 10, 2008 Cool thread. With regards to power supplies, wouldn't a standard PC power supply do the job? Link to comment
coolwaters Posted January 10, 2008 Author Share Posted January 10, 2008 yeah but its not a regulated power supply. people get confused about LEDs too often. it doesnt run on voltage but it does run on amperage. You all heard that appliances runs on something like 12v and they draw only as much amperage they need. but LEDs they run on amperage and they draw as much voltage as needed. at least its something like that. also LEDs can draw a lot of amps if the voltage is increased even by .5v. because it is a exponential growth. for example a standard LED can draw 50mA at about 2.5v and 200mA at 3V. but at 4v it can draw over 1000mA. if u dont get it look at this Link to comment
Gomer Posted January 11, 2008 Share Posted January 11, 2008 which is why I only use current drivers. Link to comment
evilc66 Posted January 11, 2008 Share Posted January 11, 2008 I think resistors should be outlawed as current limiters for LEDs. Link to comment
coolwaters Posted January 12, 2008 Author Share Posted January 12, 2008 LEDs are efficient why ruin it with resistors? i rather get a expensive PC power supply with a efficiency of 90% or better with those boards.(also about 90% efficient) IMO anything thats more then 90% is pretty good. a stock PC power supply (most people have them) is only about 80% efficient sometimes 70%... i got 7 blue LEDs right now so i guess i'll just use 6 to bring up my kelvin rating. probably to about a little more then10k if i use 12 white, one green, and one UV. i'll start later on it later 2night. Link to comment
coolwaters Posted January 13, 2008 Author Share Posted January 13, 2008 ok i got my 120mm PC fan. but that thing is huge... dont know if im going to even use it for the LEDs. i'll probably use it in the summer to cool off my tank. Link to comment
coolwaters Posted January 13, 2008 Author Share Posted January 13, 2008 ok iv been doing this project a little... it took a while to get the LEDs off my old projects. that thermal silicone stuff is really strong...stronger then the arctic silver epoxy...the LEDs that was held down by the epoxy just popped off but i really had to work on the silicone stuff... i got them all off without any loses. the stars are a little bent but not bad. i the second hardest part was figuring out the placement of the LEDs...had to double and triple check cuz once there on im not going to take them off again... there nicely packed together. heres some pics and the heatsink (its 7/8" tall) i know theres only 16 LEDs but the others are still being shipped. planing to add 2-4 more. Link to comment
Yang Posted January 13, 2008 Share Posted January 13, 2008 I'm very motivated to try to so this too now. Anyone thought of watercooling the leds? Link to comment
coolwaters Posted January 13, 2008 Author Share Posted January 13, 2008 i did but if u think about it. the radiator tubes...leaks, it just eats up way too much space... u people can try it tho.... cant w8 to wire them... Link to comment
coolwaters Posted January 14, 2008 Author Share Posted January 14, 2008 ok i finished wiring down the white LEDs. there was one board that didnt work so i had to work around it... but everything is fine. tested it with a luxmeter and got about 500 (my 26 PC gives about 400. and thats with over 60 degrees of reflection.) not bad for something that has 130 degrees of light. cant w8 to get the blue ones down. btw heating isnt as bad as i thought but thats with about 10 seconds of burn time. i still have to finish the casing. i really hope it keeps cool. Link to comment
coolwaters Posted January 16, 2008 Author Share Posted January 16, 2008 WOW i finally got 16 LEDs wired down thats 48 watts of light. the heatsink got a little warm after just 20 seconds. but with 48watts i wasn't surprised. i just hope it stays below 90 degrees well photobucket is down right now so i'll post pics 2morrow.....im still seeing thousands of spots.... Link to comment
strangelove Posted January 16, 2008 Share Posted January 16, 2008 WOW i finally got 16 LEDs wired downthats 48 watts of light. the heatsink got a little warm after just 20 seconds. but with 48watts i wasn't surprised. i just hope it stays below 90 degrees well photobucket is down right now so i'll post pics 2morrow.....im still seeing thousands of spots.... Looks like your getting the LED's in direct contact with your heat sinks now, are you running a fan to help move the heat out? If you can run them at or below 85 degrees than you should be good to go. Link to comment
coolwaters Posted January 16, 2008 Author Share Posted January 16, 2008 im afraid that with such a small heatsink compared with the amount of LEDs PC fans will only bring the temperature to a certain point. if this is a success i'll make a better one...cuz this is just too messy... Link to comment
coolwaters Posted January 17, 2008 Author Share Posted January 17, 2008 heres the pics i promised... its really bight a lot better then the MH at my LFS. my camera is on "firework" so it wont look as bright. but even so the last pic is too tense to see the LED. im surprised that this is just about 40watts... maybe this is enough for my ricordeas.... Link to comment
evilc66 Posted January 17, 2008 Share Posted January 17, 2008 Looking good Coolwaters. Need to get some pics of that over the tank. How's the heat on that? The heatsink you are using seems a little small for the load you are putting into it. I know 40W is not the same as a CPU, but they normally have fans blowing a lot more air across it than the low flow/noise fan you will use. I hope it works out for you. Link to comment
Hans Dorn Posted January 17, 2008 Share Posted January 17, 2008 Very nice. Did you notice how the white LEDs start glowing when the blue ones are on Regards Hans Link to comment
coolwaters Posted January 17, 2008 Author Share Posted January 17, 2008 yeah cuz the diode is responding to the light. its better if the wavelength is shorter. the UV bulb really lights them up. im going to try to use 2 fans on higher speeds then i plan if necessary. and on the small one is to keep the moonlight cool. i wish they dont get that hot.. btw heating isnt bad until the after the first or second minute. i might even rethink the heatsink again. Link to comment
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