basser9 June 6, 2012 Share June 6, 2012 My link HERES a little post that may help. REBEL es rb at 1500ma put out over 2ooomv .....xte driven at the same ma put out 1700mv. rebels at 1000ma ..1390 cree xte.....940mv most rebels run 445mn and crees 455mn. If you can get them around the same price rebels are just better right now but crees are not that far behind. Link to comment Share on other sites More sharing options...
icecool2 June 6, 2012 Share June 6, 2012 My link HERES a little post that may help. REBEL es rb at 1500ma put out over 2ooomv .....xte driven at the same ma put out 1700mv. rebels at 1000ma ..1390 cree xte.....940mv most rebels run 445mn and crees 455mn. If you can get them around the same price rebels are just better right now but crees are not that far behind. I think there is more to this debate than simply light output versus power. By the numbers you provided, the Luxeon LEDs put out 15% more light at the same drive current. What is missing from this however is the longevity of the LED itself. The Luxeon LEDs have a tendency to degrade rapidly when they are run in even slightly elevated temperatures. Here's the proof... At 700mA drive at 70C junction temperature (not unreasonable) the Rebels have a 10,000 hour lifetime while the Crees have a 85,000 hour lifetime. I'll leave it up to you whether you think a 15% increase in light output is worth a 88% decrease in LED life. Rebel Lifetime Cree Lifetime Link to comment Share on other sites More sharing options...
basser9 June 6, 2012 Share June 6, 2012 You have the wrong leds and data. A rebel es has a lifespan at l-70[70 percent of lumens] of 50.000 hours run at 1000ma[has been increased to 1500ma] at or below a juction temp of 135c. Rebel and crees are top of the line leds they have very similar lifetime numbers. They take turns putting out better and better led. Right now at this point rebel royals are just better any way you look at them......at the 3.00 price its a no brainer. Link to comment Share on other sites More sharing options...
icecool2 June 6, 2012 Share June 6, 2012 You have the wrong leds and data. A rebel es has a lifespan at l-70[70 percent of lumens] of 50.000 hours run at 1000ma[has been increased to 1500ma] at or below a juction temp of 135c. Rebel and crees are top of the line leds they have very similar lifetime numbers. They take turns putting out better and better led. Right now at this point rebel royals are just better any way you look at them......at the 3.00 price its a no brainer. I would love to correct my post with the most accurate information. Can you point me to your source material? Link to comment Share on other sites More sharing options...
basser9 June 6, 2012 Share June 6, 2012 JUST GOOGLE rebel es data sheet......pdf to large for this site. Link to comment Share on other sites More sharing options...
icecool2 June 6, 2012 Share June 6, 2012 JUST GOOGLE rebel es data sheet......pdf to large for this site. A link would have been just as easy and probably less contentious. For those interested, you can find it here: www.philipslumileds.com/uploads/17/DS61-pdf Link to comment Share on other sites More sharing options...
icecool2 June 6, 2012 Share June 6, 2012 (edited) I'm not sure which is clearer, to edit my original post or to simply post again. I'll just post again to hopefully keep things on a clear timeline... Unfortunately, Philips does not provide us with a set of graphs like Cree does for the ES LEDs (at least not that I can find, but maybe someone will tell me to google for it). This of course makes this comparison more difficult since we can't easily compare the results side by side. It also does not appear that Philips lists the air temperature these tests were performed at. For this conversation, I'll just copy the verbiage from Philips' datasheet for the Rebel ES line: Lumen maintenance for solid state lighting devices (LEDs) is typically defined in terms of the percentage of initial light output remaining after a specified period of time. Philips Lumileds projects that LUXEON Rebel ES products will deliver, on average, 70% lumen maintenance (L70) at 50,000 hours of operation at a forward current of 1000 mA. This projection is based on constant current operation with junction temperature maintained at or below 135°C. This performance is based on independent test data, Philips Lumileds historical data from tests run on similar material systems, and internal LUXEON reliability testing. Observation of design limits included in this data sheet is required in order to achieve this projected lumen maintenance. (Source: http://www.philipslu...ds/17/DS61-pdf) Edited June 6, 2012 by icecool2 Link to comment Share on other sites More sharing options...
basser9 June 6, 2012 Share June 6, 2012 (edited) My linkhttp://s919.photobuc...TING/?start=all To help people see and understand the different leds out there most of the leds out there were tested on this link. The rebel data is how any led is rated. As reefers you need data at the drive currents we use[700ma/1000ma/1500ma] and the temps we expect to run them at. I am no expert on rebels but my understanding is that they make a cheap version[allngap] and the rebel and rebel es[ingan]. The chart you posted is of there allngap die and there is a chart on that page that shows the ingan die. Trying to post it but no luck. My understanding of rebel vrs cree dies is that in the temps that we run are leds rebels perform better and at super high temps like 150 crees still light up and last longer but who really cares about running a led at crazy temps. You can expect 70 percent or more from cree or rebel es after 50.000 hours at normal temps.......seems like a fair statement. Edited June 6, 2012 by basser9 Link to comment Share on other sites More sharing options...
icecool2 June 6, 2012 Share June 6, 2012 Fair enough. No arguments here. There is a paper that Sanjay wrote that I need to fix and put up here. It talks about the light patterns and intensities of commercially made fixtures. Link to comment Share on other sites More sharing options...
icecool2 June 8, 2012 Share June 8, 2012 I found the link I mentioned earlier.... This isn't a comprehensive list by any means, but it is certainly interesting data. http://www.manhattanreefs.com/lighting Link to comment Share on other sites More sharing options...
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