coolwaters Posted January 7, 2008 Share Posted January 7, 2008 copper absorbs heat really well and aluminum releases it better. like what evilc66 said. also did some research. i dont know about luxeons...had pretty bad experiences with them...but never the less they are durable and can be over driven better then other brand LEDs. its funny how luxeon jumped from 45lumens per watt to about 100lumens. Link to comment
strangelove Posted January 8, 2008 Share Posted January 8, 2008 Got my Luxeon Rebels today (540lumens!!). Holy are they ever bright! I screwed one onto a heatsink that I had kicking around and powered it up with a lab power supply in constant current mode. I can still see three little spots when I close my eyes . Just for fun I taped a thermocouple to the side of the heatsink and tried running it at various currents. Up to 400mA I was able to easily keep the temp below 35C. I tested up to 600mA and then lost my nerve. The temperature was getting up around 50C on the heat sink and I suspect that the junction was pushing 60C. Not wanting to cook them on the first day I put things away. The shimmer with this over the aquarium was amazing! I also got a used BC29 canopy from my LFS so I'll have a platform to mod without impacting my original canopy . Gotta wait for the parts from Kaidomain that CW recommended. Then I'll get busy. More details to follow when the next parts arrive. CHeers NRG I'm just wondering it the rebels are that bright that they hurt your eyes, what might they be doing to fishes eyes? Link to comment
coolwaters Posted January 8, 2008 Share Posted January 8, 2008 its not that bright...if it does hurt their eyes then thos 400w MH will probably do more damage. to look directly into the lights people =P Link to comment
NanoReefGuy Posted January 8, 2008 Share Posted January 8, 2008 There's a new opportunity ... Fish sunglasses Actually if you think of nature you would see spots if you looked directly at the sun. Fish are exposed to this in the wild all the time. Even with the amount of light from these LEDs I suspect it will be less bright than a tropical reef. I know from taking pictures when SCUBA diving in shallow water I can take pictures around 1/60s@f8/ I can't take a picture of my tank with these settings and get good exposure. Most of my tank pictures are taken on a tripod around 1/25@f4. No fish were hurt in the making of this light... Cheers NRG Link to comment
Hans Dorn Posted January 8, 2008 Share Posted January 8, 2008 Hi evilc66, what are you using to protect your light from salt water? I tried putting in a polystyrene sheet, but it reflects an awful lot of light - much more than the water surface. Regards Hans Link to comment
coolwaters Posted January 8, 2008 Share Posted January 8, 2008 Hans try using a thin layer of cell-cast acrylic or GP acrylic. clearest thing i have ever seen. cuz my tanks is made from it. XD I'm planning to use a light diffuser and hopefully wont lose that much light. Link to comment
strangelove Posted January 8, 2008 Share Posted January 8, 2008 There's a new opportunity ... Fish sunglasses Actually if you think of nature you would see spots if you looked directly at the sun. Fish are exposed to this in the wild all the time. Even with the amount of light from these LEDs I suspect it will be less bright than a tropical reef. I know from taking pictures when SCUBA diving in shallow water I can take pictures around 1/60s@f8/ I can't take a picture of my tank with these settings and get good exposure. Most of my tank pictures are taken on a tripod around 1/25@f4. No fish were hurt in the making of this light... Cheers NRG Good point. Link to comment
NanoReefGuy Posted January 8, 2008 Share Posted January 8, 2008 Hi I was wondering if putting a mirror polished piece of stainless behind the LEDs would reduce part of the problem. Light may have to pounce back and forth a few times but it would probably have more coming through the acrylic in the end. Kind of reminds me of building a gas pumped laser NRG Link to comment
coolwaters Posted January 8, 2008 Share Posted January 8, 2008 well im going to do that. everything (except the LEDs of course) wil be covered with mylar i find that stuff great and very cheap. u need something with IR filtration if u want to use MH... anyone know if Weld-on #16 will bond eggcrates aka light diffusers to acrylic? last thing i want is for my heatsink to fall into the tank. Link to comment
AdriftQuasar Posted January 8, 2008 Share Posted January 8, 2008 I'm really excited about what LEDs might be able to do for aquariums and as soon as it becomes economical to take that plunge, I will, but until then, I'll keep reading. Link to comment
evilc66 Posted January 8, 2008 Author Share Posted January 8, 2008 It's getting closer to being practical, but not just yet. It has been a lot of fun experimenting with all of this, as anyone else that has gone the LED route will tell you, even though it has cost a few bucks along the way. I'm just protecting the LEDs with acrylic. The enclosure is covered on all sides (with venting of course), and I don't see much if any light lost between covered and uncovered. If light losses are an issue, one option would be to cover the electrical contact points of the LEDs with epoxy (once everything is soldered of course) and leave the lense uncovered. It may act as a bit of an insulator though. NRG, when are you starting to sell Fish Sunglasses? Link to comment
coolwaters Posted January 8, 2008 Share Posted January 8, 2008 most countries are already converting their street lights to LED and other buildings. US is falling behind once again... Link to comment
evilc66 Posted January 8, 2008 Author Share Posted January 8, 2008 Not so. The city of Ann Arbor MI (University of Michigan home) just cut a deal with Cree to convert their street lights over. Don't know when it is going to be complete, and I'm sure there will be more coming soon. I don't think the change in Europe is as prolific as you state. They still have to find the financing too. Interestingly enough, Canada was one of the first contries to change to LED street lighting. Kinda funny that a PC cooling company (Coolermaster) did the thermal management of the lamps. Link to comment
neanderthalman Posted January 8, 2008 Share Posted January 8, 2008 Interestingly enough, Canada was one of the first contries to change to LED street lighting. Kinda funny that a PC cooling company (Coolermaster) did the thermal management of the lamps. Wait, when did this happen? All I ever see are HPS and MH (might be MV, can't tell for looking) Link to comment
bfedick Posted January 9, 2008 Share Posted January 9, 2008 +1 on Neanderthalman. Most of the traffic signal lights in Western Canada are LED but I've never seen an LED lamp for street illumination. Link to comment
NanoReefGuy Posted January 9, 2008 Share Posted January 9, 2008 Hi Evil One custom pair of fish sunglasses coming soon. They'll be for sale on EBay along with a bridge that I have for sale.... I live in Western Canada and can tell you that the street lights are still HPS, but most traffic lights have been con verted to LED. I imaging that most cities will make the change eventually (SOON ). Cheers NRG Link to comment
evilc66 Posted January 9, 2008 Author Share Posted January 9, 2008 Sorry, I guess I implied that the entire country changed over. I found a few articles about some cities striking deals with LED manufacturers to do the changeover. I'll have to find the article, but it was Phillips Osram that did the job (Golden Dragon LEDs). The US has been doing major traffic signal conversion (at least in my area) for the last couple of years. I like them much more than the incandescent versions. Edit: Found the one I was looking for. http://www.ledlightforyou.com/Services/LED...n=eng&id=20 And looks like Toronto may have beaten them by a month or two. http://www.semiconductor-today.com/news_it...LEDC_110707.htm Link to comment
bfedick Posted January 9, 2008 Share Posted January 9, 2008 Thanks for the link interesting reading. Next time I go to Banff I'll pay attention. Link to comment
neanderthalman Posted January 9, 2008 Share Posted January 9, 2008 VERY COOL. This is the first I'd heard..... We've been using LEDs for traffic signals for quite some time now. Not general illumination though, so this'll be pretty sweet. Link to comment
coolwaters Posted January 10, 2008 Share Posted January 10, 2008 is anyone else using high diffusers? or eggcrates? iv noticed if the high is dense i get a lot of shadows. Link to comment
Gomer Posted January 10, 2008 Share Posted January 10, 2008 is anyone else using high diffusers? or eggcrates? iv noticed if the high is dense i get a lot of shadows. Shadows plus shimmer is the desired effect of point source lights that people like in metal halides funny you want to get rid of it. Link to comment
evilc66 Posted January 10, 2008 Author Share Posted January 10, 2008 iv noticed if the high is dense i get a lot of shadows. Imagine that You are replicating a light source similar to a MH. You will get shadows from any point light source. Eggcrate will limit the light at the edges of the tank, as the opening that light passes gets smaller as the angle off center increases. A diffusor might work better than eggcrate. Link to comment
coolwaters Posted January 10, 2008 Share Posted January 10, 2008 Shadows plus shimmer is the desired effect of point source lights that people like in metal halides funny you want to get rid of it. guess im just too used to PC lights and T8s... Link to comment
oogie Posted January 10, 2008 Share Posted January 10, 2008 This is GREAT! Someone actually keeping up with LED lighting project! PLEASE keep it going, and start adding corals to see which coral responds betterm or worse..... That fixture looks awesome! Industrial baby! Link to comment
snowlancer2720 Posted January 10, 2008 Share Posted January 10, 2008 i finally got my fixture up an running, 6 neutral white and 8 royal blue rebels all 3.6v in a diy acrylic housing. i ran into a problem though, the ballast decides to buzz and then shut off, but it goes back on again a few seconds later, and then off again..there isnt anything to ground so i know that that is not the problem, coolwaters or evilc or anyone else for that matter, do you guys know whats going on with it Link to comment
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