# New Luxeon: Rebel



## Long John (Mar 27, 2007)

It's done.

New Luxeon-Led's:

http://www.lumileds.com/newsandevents/releases/PR68.pdf

Best regards

____
Tom


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## benp1 (Mar 27, 2007)

i dunno what this means but it looks good!


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## Jay R (Mar 27, 2007)

Oh crap. Seems like just yesterday I upgraded my Raw NS to a Cree.


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## jc28841 (Mar 27, 2007)

And I've just had the L1DCE for like a month. Just ordered the 2AA tube too...
Oh well... can't have too much light in your life.... right?


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## LEDcandle (Mar 27, 2007)

Looks really small, prob won't be a direct swap... why not make it the usual luxeon size but brighter. 

Anyway, seems like lumens/watt is not anything to shout about; around the same level as the current Cree/SSCs.


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## Kilovolt (Mar 27, 2007)

Friends rest assured: there's no sleep in front of true flashaholics, every other day someone will come out with new products that outshine the previous ones.

Better start putting some money away pretty fast, many purchases needed soon :naughty:


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## Long John (Mar 27, 2007)

IMO it looks very promising. The big advantage: The smaller the light source-the better collecting the light.

Best regards

____
Tom


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## heliyardsale (Mar 27, 2007)

Long John said:


> It's done.
> 
> New Luxeon-Led's:
> 
> ...


 
Dang it! That's it, I'm unplugging my computer from the internet.... This forum is costing me waaay too much $$$$
Heli
:huh2:


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## monkeyboy (Mar 27, 2007)

The die size is 1mm^2, same as the Cree xre. It's just the overall package that is smaller. That can't be a bad thing though.


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## x2x3x2 (Mar 27, 2007)

just what i was thiking, dye size seems the same.
so does the identical looking spec of 70lm/w at 350ma... claimed anyway. could they perhaps be using the same technology?


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## monkeyboy (Mar 27, 2007)

They must use similar (copied?) technology since I can't imagine that Luxeon would use the Cree die. Judging from the length of time taken for them to bring out the K2, I estimate that these will hit the market towards the end of 2008 :laughing:


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## cage (Mar 27, 2007)

I cant find a way how to order samples. Have any of you guys ever get them from lumileds?


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## Casual Flashlight User (Mar 27, 2007)

Does it have a glass dome? I'm thinking it may be _the _emitter for an Arc AA upgrade.







CFU


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## Long John (Mar 27, 2007)

Casual Flashlight User said:


> Does it have a glass dome?
> 
> 
> CFU



No, silicone

Best regards

_____
Tom


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## Casual Flashlight User (Mar 27, 2007)

So now I'm thinking it's probably not the new, super modern emitter for an Arc AA upgrade.





Cheers for the info LJ.


CFU


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## orbital (Mar 27, 2007)

360 views, w/ integrated ceramic, overall layout,

http://www.lumileds.com/products/line.cfm?lineId=19


~How will CREE answer..


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## cy (Mar 27, 2007)

hmmm.. those tiny leads ...


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## Long John (Mar 27, 2007)

"Rebel" is the perfect name for them......it will be a rebellion in Led-light technology:rock:

Hopefully they will be available soon.

*PhotonFanatic* where are you?:lolsign:

Best regards

____
Tom


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## monkeyboy (Mar 27, 2007)

You could fit 4 of these into the same footprint as the XR-e






I'm sure a reflector or optic could be designed to collimate this.


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## dcjs (Mar 27, 2007)

monkeyboy said:


> You could fit 4 of these into the same footprint as the XR-e
> 
> 
> 
> ...




That's kind of funny, the first thought I had upon seeing the tiny LED was "Those things are small enough to put _four_ of them in _one_ reflector!"
Talk about the mother of all donut holes, though..


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## wasBlinded (Mar 27, 2007)

monkeyboy said:


> You could fit 4 of these into the same footprint as the XR-e
> 
> I'm sure a reflector or optic could be designed to collimate this.


 
It would be very hard to collimate well. And the better it is collimated, the worse a center donut or dark cross in the beam would be.

Defocusing it enough to hide the emitter layout induced artifacts could be done, but then you would have a flood beam.


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## SemiMan (Mar 27, 2007)

It is not so much the size of the die that is important as it is the "effective" size of the emission source. I will have to ask our optics guy if he knows the values for the standard Luxeon. I think it is close to 2mm * 2mm (put a ruler up against the package and that is the size you will measure, not 1mm * 1mm). I think for the CREE XRE it is bigger. Using my precision measuring tool (a ruler with mm markings), the Rebel die measures smaller, close to 1.5mm. It may just be that the die is much easier to see in the Rebel package though.

Semiman


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## COMMANDR (Mar 27, 2007)

monkeyboy said:


> You could fit 4 of these into the same footprint as the XR-e
> 
> 
> 
> ...


 
Heat may be a problem if you pack them that tight, heat sinking them will be a challenge. 


Gary


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## SemiMan (Mar 27, 2007)

Well we could look at this another way, put one right in the optical center and three spaced around it with a multi-mode switch. The center LED could be driven hard for a bright tight beam, and the three others could be used to provide a powerful flood capability. They are small enough you could get really creative with the packaging.

I foresee lots of burnt fingers trying to figure out how to mount and solder these properly. Our Future sales reps says the lower brightness bins will be cheap so that will be good for test prototyping as opposed to using your good ones.


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## monkeyboy (Mar 27, 2007)

OK, you probably would be better off separating the emitters like in the Elektrolumens QSP for collimation and cooling purposes. I just thought it would make an interesting optical design project. I guess a large reflector would do the trick but it must be possible to design something in a smaller package?

On the otherhand this would make a good layout for a Surefire-L4-style floodlight


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## orbital (Mar 27, 2007)

Multi core is the future in technology.
If its CPUs, GPUs, high speed RAM, and now very possibly LEDs. 

Lumileds use of ceramics and the electrically isolated thermal pad is most interesting.


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## pilou (Mar 27, 2007)

One nice thing is the availability of various color temperatures for these LEDs.


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## pilou (Mar 27, 2007)

Just a thought: could these show up in the new Inova T1 that is alleged to be a pocket rocket?


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## orbital (Mar 27, 2007)

pilou, I did a thread on that just last night.

Lumileds and Inova


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## 65535 (Mar 27, 2007)

This is perfect, exactly what I need micro SMD High powered LED's.

" Tri-Rebel M(6)5535 "

This is a dream come true.


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## chris_m (Mar 27, 2007)

Have you guys all missed the earlier discussion on this? http://candlepowerforums.com/vb/showthread.php?t=150005&page=9&pp=30

It would appear this isn't an LED of great interest to us - worse basic performance than an XR-E or SSC P4. We're actually waiting on another release from Lumileds which should be a LOT more exciting (though probably not available for sale until 2009!)


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## bombelman (Mar 27, 2007)

nice....


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## Daekar (Mar 27, 2007)

I guess this means I should hold off on buying any more lights til we find out release info and the incredible minds here figure out new and exciting ways to use more than one of them at a time. I'm thinking that 3-led side-emitter is looking better all the time...

Of course, now everything else is obsolete... That means new single-led lights too...


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## Outdoors Fanatic (Mar 27, 2007)

New SureFire lights ahead?


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## 65535 (Mar 27, 2007)

Chris it's the size that is interesting.


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## EngineeringGuy (Mar 27, 2007)

The two best things about these is that the 80lm/w bin are actually as efficient as Cree P4 bin at higher drive currents due to the "anti-droop" technology (what marketing idiot came up with that name), and that they work phenomenally well with reflectors. ... my 0.02.

Contrary to what a lot of other people have been saying in previous threads, in my opinion, these rebels Are about the BEST form factor for a flashlight. The small size of the dome over the die allows you to make a truly tiny reflector which actually creates a usable beam. I am imagining an Arc AA form factor which is as bright as, and has a beam as nice as an HDS EDC 60?

The one drawback to these emitters is that they are not the most freindly package for do-it-yourself modders. Reflow soldering isn't exactly complicated, but it will be a deterrent for many people.


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## chris_m (Mar 27, 2007)

Maybe if you want either to get a really tight beam, or have a really small form factor light the size of the dome and the ability to have a smaller reflector is interesting. I'd suggest that for any other application (which is the majority) it's not actually that useful.

Meanwhile I'm not convinced there is any evidence of "anti-droop" technology in the data-sheet. Looking at the graph on page 16 of http://www.lumileds.com/pdfs/DS56.pdf it seems you only get 2.1 times the lumens at 1000mA compared to 350mA, which is no better than an XR-E, and worse than a SSC P4. Then again, that also contradicts the info earlier in the datasheet, as the figure for 700mA is no better than 1.65 times (again not significantly better than an XR-E), which would imply ~130lm for the 80lm nominal part, not the 145lm they claim. I'm not sure whether this discrepancy is down to different testing regimes, bearing in mind that Lumileds are reported to test using extremely short pulses, which is bound to overrate the higher current performance.

Also given that P4 bin XR-Es have been tested at 145lm at 700mA (Q2 bin now available), and SSC P4 at 155lm, that 145lm for the *best* bin is nothing special.


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## TMorita (Mar 27, 2007)

EngineeringGuy said:


> The two best things about these is that the 80lm/w bin are actually as efficient as Cree P4 bin at higher drive currents due to the "anti-droop" technology (what marketing idiot came up with that name), and that they work phenomenally well with reflectors. ... my 0.02.
> ...


 
I tried completely enclosing an LED die in aluminum once.

It dissipated heat very well, but had other problems.

 

Toshi


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## Lexus (Mar 27, 2007)

Those neutral white 4100 K LEDs look interesting. I wonder if they render colors better than the 6500 K ones. Btw they have the same efficiency as the cool white LEDs.


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## Calina (Mar 27, 2007)

Gen X LEDs will likely be more interesting for us though I would be curious to see the pattern emitted by two, back to back or three mounted on a triangular base (heat dispersion problems?). Their tiny size will make them a PITN (pain in the neck) to work with. 

The cool white will likely be very blue.





Notable : the neutral white efficiency is as good as the cool white ones.

Vf is low, 2.55 V minimum, that is something new. I envision an exciting new generation of button cells fashlights. Can you picture new Photon at 20 lm.


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## SemiMan (Mar 27, 2007)

Cree and Seoul both test their LEDS with pulse currents as well. That is how they rate their parts at a die temperature of 25C. The only way to do this is with pulse testing. It does not represent the real world, but it is consistent.

I am pretty certain these parts do not have anti-droop. I do not think that is going to be later (much?).

The Seoul P4 is interesting, but the spectrum as far as I am concerned has been tuned for specifications, i.e. high lumens, not necessarily useful light. The color rendering can be very poor depending on the subject. They use the same die as Cree, so you can see how many more lumens you get by changing the phosphor. The Cree parts have much more consistent color rendering and for flashlights where you never know what you are going to be lighting up, I think they are much better.

If I am interpreting the Rebel data sheet correctly, the 80 lumens is a minimum, the 145 is a typical so I do not think anything is wrong there. 

One thing that I found interesting is that the Rebel is rated for its 50K hours at 135C, not 85C like Cree. While the Rebel is only rated for 1A, I wonder if we can drive it hard based on this with reduced life or it will just fail quickly. Should be interesting to find out, however, until we can see more parts, I will keep playing with the XRE.



Semiman


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## Calina (Mar 27, 2007)

Lexus said:


> Those neutral white 4100 K LEDs look interesting. I wonder if they render colors better than the 6500 K ones. Btw they have the same efficiency as the cool white LEDs.


 
You beat me to it.


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## Calina (Mar 27, 2007)

SemiMan said:


> If I am interpreting the Rebel data sheet correctly, the 80 lumens is a minimum, the 145 is a typical so I do not think anything is wrong there.
> Semiman


 
The 145 lm figure is at 700 mA the 80 lm is for a 350 mA current.


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## PhotonFanatic (Mar 27, 2007)

Long John said:


> "Rebel" is the perfect name for them......it will be a rebellion in Led-light technology:rock:
> 
> Hopefully they will be available soon.
> 
> ...


 
Waiting to hear back from Future. 

Pricing, etc., you know, the little details.


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## soffiler (Mar 27, 2007)

PhotonFanatic said:


> Waiting to hear back from Future.
> 
> Pricing, etc., you know, the little details.


 
Let us know what they say! Personally, I'm curious which of the 11 white part numbers are actually available right now. And, surely, the binning is going to be reflected in the pricing.


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## McGizmo (Mar 27, 2007)

The small package will allow the Rebel to be used in applications unsuited for the larger LED's. In terms of collimation for use in a flashlight, I am not sure there is any real gain. The size allows for mating with small reflectors of short focal lengths to be certain but with a short focal length, you will have significant divergence in the beam due to the relative image size to focal length. The Seoul 1/2 watt for instance can be used with a small reflector with better collimation results than the Rebel because the die in the 1/2 watt is smaller.

The Rebel is not friendly to the type of mod work and scale we are used to with the larger packages. The soft gummy dome is not good for mechanical referencing or indexing off of and centering can be a challenge.

I think the Rebel will be well received (provided flux claims are real ) in any number of LED applications but not necessarily or limited to flashlights. Color and tint consistency from Lumileds is anticipated to be superior to the others and the Rebel may be an example soon seen in real production items. The warmer color temperatures should be well received by the SSL industry I would imagine. In regards to flux claims, I have a few samples that are not claimed to be at the 80 lumen min but at about half that. From my simple and crude testing with an uncalibrated integrating sphere, it seems that the samples I have are compliant with mfg claims. This leads me to believe that there is a real chance that the 80 lumen min parts will be _as]/i] advertised.

I think the Rebel represents a new form and alternative LED light source that can be added to our growing bag of tricks. The little fella will require attention to detail and some time to become acquainted with but seems worthy of consideration.

The above is JMHO.

As soon as I get my hands on a 80 lumen part, I plan to get more serious in getting to know the Rebel.




_


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## Long John (Mar 27, 2007)

:thanks: Fred and Don for the feedback :twothumbs


Very best regards

____
Tom


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## chris_m (Mar 27, 2007)

SemiMan said:


> If I am interpreting the Rebel data sheet correctly, the 80 lumens is a minimum, the 145 is a typical so I do not think anything is wrong there.



Good point - I'd not noticed that. Would explain the difference, though given the graph later in the datasheet it would seem that a min 70lm part is actually typically 80lm (at 350mA) and an 80lm part typically 90lm  That still makes the 80lm part not quite as good as a Q2 bin Cree, and I'm guessing they may also be about as easy to get hold of as a Q3 bin Cree!

I'm still not getting excited about these (they will be great for some applications, but not I think that handy for us modders), though looking forward to the Gen-X.


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## milkyspit (Mar 27, 2007)

orbital said:


> Multi core is the future in technology.
> If its CPUs, GPUs, high speed RAM, and now very possibly LEDs.




Luxeon V is a multi-core device along the lines of your definition. It's been with us since 2004 at least, probably earlier.
:shrug:


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## mpc (Mar 27, 2007)

I does make me think of a couple of things. Higher efficiency at lower currents and less heat generated for each emitter. I wonder if a smaller version of the McGizmo Three Shooter would be possible with longer runtimes, and without the need to make a special reflector.


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## 65535 (Mar 27, 2007)

They are soo small I can fit three in an array that will fit throught the hole in a SF light and allow my to make a 3LED SF trubo head.


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## PhotonFanatic (Mar 27, 2007)

In the excitement of the announcement, we often overlook some of the mundane items, such as this:

_Sampling of the warm-white and neutral-white products begins immediately with volume_
_production later this year._

Translation: Future does not have any or the warm-white or neutral white Rebels for sale, and won't have them for some time. 

So that leaves only the cool-whites availabe for immediate purchase, but Future hasn't had time to bin sort what they have received yet. Nothing like ordering an unknown bin--I've always had great results doing that. :lolsign: 

Short story--it will be a while before I get any of these in for sale as I like to know what bin I will be selling to my customers, and I presume you would also like to know what you are buying, too.


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## Long John (Mar 27, 2007)

Fred..............

The same procedure like every year:lolsign:


Best regards

_____
Tom


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## PhotonFanatic (Mar 27, 2007)

Long John said:


> Fred..............
> 
> The same procedure like every year:lolsign:
> 
> ...


 

Yeah, and I thought they were definitely not going to do the announcement until the product was on Future's shelves. Well, it is on Future's shelves, just not all of it. 

To be honest, the Gen-X is really the LED that we want and we know we'll be waiting a while for that, too.


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## IsaacHayes (Mar 27, 2007)

SemiMan said:


> If I am interpreting the Rebel data sheet correctly, the 80 lumens is a minimum, the 145 is a typical so I do not think anything is wrong there.



If you are looking at the highest availible part #'s for cool white or neutral white, ending in 0080 then 80lm at 350ma yes. And 145 typical is at 700ma.

PhotonFanatic, are the 0080 part #'s availble? Or are they un-obtainum like the higher binned part # K2's?

Like you say, this is not the part we want really. They are interesting and I'm sure some experimenters will put them in things. They are small, and I can see them going in camera phones/etc. And the flux isn't anything really to get excited about, looks like the best part # is right about on par with the ezbright1000 die based leds (xre,p4,edison) if you don't de-rate it and just go by spec sheets. Neat but I won't be swapping my leds out for this led.


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## LG&M (Mar 27, 2007)

Think how many Inova could put in a X5! Maybe 20 @ 350mA.


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## Art Vandelay (Mar 27, 2007)

Seoul is using Cree technology, why not Philips?



x2x3x2 said:


> just what i was thiking, dye size seems the same.
> so does the identical looking spec of 70lm/w at 350ma... claimed anyway. could they perhaps be using the same technology?


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## IsaacHayes (Mar 27, 2007)

They make their own die's, and are a competitor. That's like asking why isn't AMD using Intel chips or something...


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## zk188 (Mar 27, 2007)

Jay R said:


> Oh crap. Seems like just yesterday I upgraded my Raw NS to a Cree.


 



You know what else sucks buying a Nintendo DS only to have the DS Lite announced the following week.


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## mds82 (Mar 27, 2007)

What ever happened to the luxeon clam that they can produce 115lm/watt ? interesting


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## Art Vandelay (Mar 27, 2007)

Competition and cooperation are not always mutually exclusive. 
http://www.ledsmagazine.com/news/4/1/32/WhiteLEDpatents
http://www.answers.com/keiretsu&r=67



IsaacHayes said:


> They make their own die's, and are a competitor. That's like asking why isn't AMD using Intel chips or something...


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## IsaacHayes (Mar 27, 2007)

Here are the only Rebel Parts to show up:

Warm White:
 LXML-PWW1-0050 50lm @ 350m Warm White (Reel / Call for avail. / Qty 500)

Also showing up (non-whites)
 LXML-PB01-0008 8.2lm @350ma BLUE (Broken reel / 1,000 in stock / Pkg Qty 1)
LXML-PD01-0040 40lm @350ma RED (Broken reel / Call for avail. / Pkg Qty 1)


Remember XRE was tested by NIST, real world conditions. 350ma on a fairly small heatsink, 84 lumens. Now look at the Rebel datasheet PDF. Check out Page 14, Fig 6 for thermal pad de-rating and also Page 16, Fig 10 for current derating.


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## ViReN (Mar 27, 2007)

> Now look at the Rebel datasheet PDF. Check out Page 14, Fig 6 for thermal pad de-rating and also Page 16, Fig 10 for current derating.
> Reply With Quote


indeed!....what a *disappointment *again!


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## SemiMan (Mar 28, 2007)

IsaacHayes.....

I am not sure how Cree is any better. Their parts degrade w.r.t. die temperature (and faster) and they also have thermal derating as well. NIST tested "two" parts, no doubt a good ones that were picked out for their performance. Someone has created a misconception that Cree tests their parts differently. They do not. Their lumen measurements are at 25C just like Lumileds, or Seoul, or Nichia or anyone else. These are short pulse based measurements.

Not many of my XREs will test out to 84 lumens on that heat sink, though they are likely only degraded by 7-8% on that heat sink at 350mA

Semiman


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## Mags (Mar 28, 2007)

'bout time Lumileds. I feared that you were a goner.


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## hank (Mar 28, 2007)

>NIST tested "two" parts, no doubt a good ones that were picked out for their performance. 

It would be interesting to know if that's true. I recall, back when the US set limits on how much lead household faucets could leach into drinking water, I came across a posting from someone whose employers were very unhappy because they'd prepared some very low-lead samples to send from the home office to the USA to be submitted for testing --- and the nefarious government agency had gone out and bought their samples anonymously to get honest results.

By contrast the private Underwriters Labs takes samples specially prepared for testing, and so is more likely to be fooled by specially prepared "samples" submitted by manufacturers -- or used to be last I heard.

It'd be nice to know if NIST does it that way.


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## ViReN (Mar 28, 2007)

SemiMan said:


> IsaacHayes.....
> 
> I am not sure how Cree is any better. Their parts degrade w.r.t. die temperature (and faster) and they also have thermal derating as well. NIST tested "two" parts, no doubt a good ones that were picked out for their performance. Someone has created a misconception that Cree tests their parts differently. They do not. Their lumen measurements are at 25C just like Lumileds, or Seoul, or Nichia or anyone else. These are short pulse based measurements.
> 
> ...



Semiman.. :nana: by any chance you work for Philips/LumiLED's  (just kidding)

I really hope luxeons are up to the mark this time.... let us have production samples and let them be tested by NIST or some thing similar, under "Normal" conditions, like the Cree's... perhaps we at CPF could do that to have a unbiased option (if you are concerned) .... jtr1962, NewBie (sadly retired) ... and others can test em too.... 

Wether they are binned at 25 or 0 degrees, dosent really matters, what matters is how they perform in "real world" situation.... let us all not argue on how they are binned, but we definately need to discuss on how they perform (in comparison with each other).... the Cree's the Luxeon's and the Seoul's .... the winner of course will be the one which performs best (for a given criteria).

what i liked about Luxeon is they have now tighter binning structure (both flux and tint) and also they are boldly specifying the binning temprature as against previous datasheets 

i do not ahve any favour / bias for luxeon/cree/Soul.. but i really like Cree's cos of their brightness.... tomorow, if luxeon's rebel or K2 outperform them i will start liking them


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## ViReN (Mar 28, 2007)

Oh .. I almost forgot.... but it would be a worth to mention.... Let the Imagination begin 

Imagine Peak's 3 LED AAA, Pocket Body with Rebel
Imagine Arc AAA with Rebel
Imagine Fenix L0P...err L0P-RE with Rebel
These are going to be the brightest and smallest lights ever seen till date


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## yellow (Mar 28, 2007)

I dont get it.

the BEST bin mentionned is at best equal to Cree P4/SSC (how about availability, remember how "easy" to get best bins were at Luxeon's?), while we (at least I) wait for the "Q" Bins to arrive.
Nothing better and for sure not that great invention that has been claimed the last weeks (maybe quite great if compared to the older Luxeon makes, but why compare anything with overcome technology?).

then size:
wow, great. But even with the Cree shorting out the leads with a reflector is possible. Now here: 
* mounting/glueing it in place: possible but difficult, 
* soldering the leads: same
* putting a focusing device on? how? is there still enough space around? What about the wires? 

But pos is: pad electrically neutral, thats great. :thumbs up: 

really wonder how the story goes on...


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## chris_m (Mar 28, 2007)

Phew - I was thinking for a while there that I was the only one not getting over-excited about this. I'm sure it's a great part for some applications (notably where space is at a premium), but it's not going to make better flashlights than is possible with existing LEDs (ie ones the retailers have in stock right now).

Good job that pad is electrically neutral - given a junction-pad thermal resistance of 10 degrees/W it will still be struggling to dissipate heat as well as a P4 (thermal resistance 6.9 deg/W) with a layer of isolating epoxy!


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## SemiMan (Mar 28, 2007)

I agree we have to have independant testing of these LEDS to know how they really do. The NIST testing was paid for by Cree and when I read the report and look at what was supplied (parts on a board matched to a heat sink), I would expect Cree provided them. Either way, they are still the brightest usable light LED we can buy. I do have a bit of a bias against Seoul only for the fact I do not like the spectrum of the LEDS. In my day job, my customers expect things to look the right color. The XR-E are doing a good job at that.

My equipment budget I submitted this year included a goniometer/spectrophotomer (ok a cheap one), but it was the best I thought I could get by my boss. If that comes through, we are talking calibrated beam plots!!! ... the holy grail of flashlight testing. 

I have told my Future rep that before they give me any samples, I want them characterized....  I was disappointed that the K2 never lived up to what it was advertised.


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## Opto-King (Mar 28, 2007)

Hello guys, 
Is it just me or is the Relative Luminous Flux lm/mw Vs Thermal pad temperature mesaured at below 20degree and not at 25?

Looking at the graph on page 14 of http://www.lumileds.com/pdfs/DS56.pdf 
:huh2:


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## soffiler (Mar 28, 2007)

Opto-King said:


> Hello guys,
> Is it just me or is the Relative Luminous Flux lm/mw Vs Thermal pad temperature mesaured at below 20degree and not at 25?
> 
> Looking at the graph on page 14 of http://www.lumileds.com/pdfs/DS56.pdf
> :huh2:


 
No, it's not just you. The way I see it, that particular chart has a bit of weirdness in it. First and foremost, you would expect all the lines to intersect right on the horizontal "1.0" line but they don't....eyeballing the intersection (not easy to do as the lines are fat) looks like it's around 1.04 or so. Looks like the blue line crosses 1.0 at 16C and the green line at 24C. Most likely some graphic artist got ahold of that chart and took some liberties for his own purposes before it hit print. It *does* appear that the "average" temperature is 20C, not 25C as you'd expect. Final comment, it's really the slope of those lines that is most interesting. Knowing the slope you can shift the lines around as needed.


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## DM51 (Mar 28, 2007)

SemiMan said:


> My equipment budget I submitted this year included a goniometer/spectrophotomer (ok a cheap one), but it was the best I thought I could get by my boss. If that comes through, we are talking calibrated beam plots!!! ... the holy grail of flashlight testing.


Has this been done before? It sounds interesting. We know the criticisms people have of LED lighting – it’s too blue, too harsh, too cold, too flat, etc, etc, etc – so will this equipment give us a better idea of which particular component(s) of an LED’s spectrum it is that people dislike so much, and where the manufacturers could make improvements?


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## CM (Mar 28, 2007)

Yaaaawwwwn. 70 lumens per watt is no groundbraker. Shrinking the die is no groundbreaker either. You still have to have a reflector/optic to manage the light. Give me 300 lumens per watt please or it's old news.


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## soffiler (Mar 28, 2007)

CM said:


> Yaaaawwwwn. 70 lumens per watt is no groundbraker. Shrinking the die is no groundbreaker either. You still have to have a reflector/optic to manage the light. Give me 300 lumens per watt please or it's old news.


 
70 lm/W was groundbreaking just MONTHS ago, not even years! Man, you guys are hard to please. My personal opinion, spoken without much industry inside info, is that the efficacy improvements we see as end-users actually follow innovations in semiconductor manufacturing technology and phosphor technology that are the work of very heavy-duty PhD's. The Rebel isn't doing any better than Cree 7090 XRE or Seoul P4 because they are all up against the same technology ceiling.

Oh, and, FYI, 300 lm/W is never going to happen. The absolute peak efficacy is 683 lm/W but that is specific to a sickly monochromatic shade of yellowish-green at 555 nm wavelength AND it requires absolutely perfect conversion of 100% of the electrical input into photons i.e. absolutely no waste heat whatsoever. For white light, the absolute pinnacle is about 240 lm/W and again that requires 100% perfect conversion of electrical input into photons, which is a long long long way off.

For the record, both lumens and watts are measures of power. Converting between them is kind of like converting from inches to millimeters. Lumens and watts aren't quite as simple as inches and millimeters, but the point here is that the relationship is fixed. One inch will never be more than 25.4 millimeters. Likewise one watt will never be more than about 240 lumens (I am forced to say "about" because that number can vary slightly, depending on exactly which wavelengths are combined to make white... this is because the human eye is not equally sensitive to all wavelengths). The only complicating factor is heat. You don't lose any millimeters to heat when you convert to inches, but you DO lose some watts to heat when you convert to lumens.


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## Gryloc (Mar 28, 2007)

Uhhhh, holy crap! This morning I was checking out the rebel availability on Future, and only 3 product showed up for LXML (first four letters for the rebel's model). I got back and hit refresh, and there is now 65 products available!!!

Of course, this includes the different bin codes and different package amounts for each type of Rebel. Check it out. I haven't looked through it much yet, but things seem pretty cheap! I wonder when some will "ship" if you would happen to purchase a few. 

Maybe I should check out Lumileds home to see whats going on...

Have fun, all...


-Tony


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## PhotonFanatic (Mar 28, 2007)

Tony,

Once you understand the bin codes, you will soon realize that there isn't anything good there yet. Those are all the low lumen output Rebels, even in the colored varieties.


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## kanarie (Mar 28, 2007)

A lot of you are forgetting that the PRICE and the STABILITY (color, failure rate) are probably the most deciding factors for a manufacture to use product A or product B in an endproduct; on paper the cheap Lumileds Rebel has good cards
The use of a highpower led in a flashlight is just a niche market


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## Gryloc (Mar 28, 2007)

Yeah, I understand. The ones for sale aren't the most impressive, but they are out there for prototyping. I might have to try a few for the heck of it. There are a few colored ones for sale with the highest bin (Royal-Blue, Amber, Red-Orange, second highest for Blue), and they aren't too bad compared to existing Lumileds products. Sure, Seoul and Cree offers more. 

Don't forget that those prices you see on at Future, until you click on the part for a description, are only for one Rebel. The prices decrease even more when you get more than 2. How can you complain when buying a $2.00 40lm/W cool white emitter when using them for home lighting and need many of them? I am not arguing against you Photon Fanatic. I am just saying all hope is not lost. You deal with premium-binned LED's all the time, so I understand where you are coming from. I am glad they are available, but hopefully the better bins are not "un-obtainable" like with the K2 emitters.

I was thinking, and the colored ones will be nice because you can finally fit more emitters (of amber, or red, or red-orange), on a small heatsink that will fit better in a stock taillight or turn-signal enclosure. You will get a little bit more efficiency by having more of them (reducing heat, too), and it will not be too expensive. Just an idea... I hope more become available for small orders. 


-Tony


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## mobile1 (Mar 28, 2007)

I dont know but the 115lu press release and now the rebel dont make much sense to me... than the k2 is still somewhere out there or is the k2 now gone and replaced by the rebel...
To me it seems like they are struggling for news.. the rebel is somewhat on par with the market but not the product that would keep their customers from switching to the crees and ssc of this world...


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## Effulgence (Mar 28, 2007)

Waiting for something solid to arrive... Dare I say... 20+ Rebel emitter light?


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## IsaacHayes (Mar 28, 2007)

28th I think was the official launch date, so that makes sense that they are all out. I remember someone mentioning the 28th.

The max flux green, royal-blue, blue, and all whites show up but call for avail...

The ones that seem to be in stock and ready are the cool-white 40 and 50lm @ 350ma versions. Bummer.


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## CM (Mar 29, 2007)

soffiler said:


> 70 lm/W was groundbreaking just MONTHS ago, not even years! Man, you guys are hard to please. My personal opinion, spoken without much industry inside info, is that the efficacy improvements we see as end-users actually follow innovations in semiconductor manufacturing technology and phosphor technology that are the work of very heavy-duty PhD's. The Rebel isn't doing any better than Cree 7090 XRE or Seoul P4 because they are all up against the same technology ceiling.
> 
> Oh, and, FYI, 300 lm/W is never going to happen. The absolute peak efficacy is 683 lm/W but that is specific to a sickly monochromatic shade of yellowish-green at 555 nm wavelength AND it requires absolutely perfect conversion of 100% of the electrical input into photons i.e. absolutely no waste heat whatsoever. For white light, the absolute pinnacle is about 240 lm/W and again that requires 100% perfect conversion of electrical input into photons, which is a long long long way off.
> 
> For the record, both lumens and watts are measures of power. Converting between them is kind of like converting from inches to millimeters. Lumens and watts aren't quite as simple as inches and millimeters, but the point here is that the relationship is fixed. One inch will never be more than 25.4 millimeters. Likewise one watt will never be more than about 240 lumens (I am forced to say "about" because that number can vary slightly, depending on exactly which wavelengths are combined to make white... this is because the human eye is not equally sensitive to all wavelengths). The only complicating factor is heat. You don't lose any millimeters to heat when you convert to inches, but you DO lose some watts to heat when you convert to lumens.



I understand what you're saying but this news is like someone saying "we have a new car that gets 12 miles to the gallon" right after someone announces that they have a car that gets 40 miles per gallon (and when people are concerned about efficiency). Yeah I know, not the same exact thing but I think understand my point. A smaller die with less efficacy is not where it's at. The big market is in dies that put out more light per given input power. I used a term lm/w but that's more or less the de facto metric when talking about efficiency. That was not meant to imply that the term watt has any meaning--I agree with you there. 

However it does not change the fact that more output and higher efficiency is where things are going. Compact flourescents are soon to be replaced by LED's that are more like Cree's XR-E and less like the Rebel. The flashlight market is small compared to the replacement market for line voltage flourescent and incandescent fixtures. And I can almost assure you we're not going to get there with "advances" like the Lumiled Rebel. To me, it's a ploy by Lumiled to distract people from the fact that they're getting their arses kicked by Cree.

Oh, and saying 300lm/w is "never" going to happen is a strong statement that I think will be proven wrong in due time. It may not happen in the next few months or years but ruling it out absolutely at this point is speculative. BTW, I threw that number out tongue in cheek but since you chose to be argumentative, I thought I should present a counterpoint.



mobile1 said:


> I dont know but the 115lu press release and now the rebel dont make much sense to me... than the k2 is still somewhere out there or is the k2 now gone and replaced by the rebel...
> To me it seems like they are struggling for news.. the rebel is somewhat on par with the market but not the product that would keep their customers from switching to the crees and ssc of this world...



Edited to add the above. I think you took the words right out of my mouth. "Struggling for news..." Reminds me of the dotcom days when companies would make worthless press releases to keep the investing public interested. Yep... Sorry lumileds, I need to yawn again.


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## daveman (Mar 29, 2007)

Three pages worth of posts about absolutely nothing.


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## EngineeringGuy (Mar 29, 2007)

CM said:


> Oh, and saying 300lm/w is "never" going to happen is a strong statement that I think will be proven wrong in due time. It may not happen in the next few months or years but ruling it out absolutely at this point is speculative.



I am going to have to side with soffiler on this one. Lumens are a measure of the light output of a device. A lumen is a unit of measure specifically weighted for the response of the human eye, but it is still a measure of output power. 

Another way to look at this is that we are converting electrons into photons. Each electron has a specific amount of energy and each photon generated also contains a specific amount of energy. We cannot generate any more photons than we have energy to produce. The lm/w figure is then the efficiency of conversion (ratio of photons to electrons). Basically it is the percentage of input energy that gets converted to the desired output energy, but the units are goofed up. If you were to convert the lumen figures to radiometric output (units in watts) then it immediately becomes obvious that you are expressing the efficiency of conversion. By definition efficiencies can never be more than 100%.

I know that there some who are holding out some hope for a cold fusion process which will allow LED lights forever and for ¨free,¨ but the energy still has to come from somewhere (its that whole E=MC² principle). The light conversion process will never be more than 100% efficient... ever. The good thing though is that if we approach 100% efficiency the devices ought to be able to be driven harder because they will produce much less heat than current devices. They can then get brighter for a given size, but not more efficient. 

Hope this wasn´t a bore to everyone...


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## Gryloc (Mar 29, 2007)

To all (and not any single person to clarify, just in case),

Its late for me, but maybe area lighting is not the goal of the Rebel LEDs. I keep hearing about these being used for full-color RBG signs, like what you see in the football/basketball/baseball stadiums (even the nice color screen on the rear of the stage on the show American Idol- something I usually prefer not to watch by the way). I suppose you can get a brighter, higher resolution display by using these versus standard LEDs due to their small sizes. I don't know. Don't forget about cell phone lighting (since the Lumiled's "Flash" emitter kinda sucks in terms of brightness. These are tiny, and, don't forget cheap (-er).

Oh, and I can see where these can affect the big-screen LCD television market. More can be crammed into a smaller place for a brighter back-lighting solution, while saving a few bucks. These are much nicer than Luxeon 1 emitters in a way when it comes to RBG backlights and lighting, right? It seems like so.

I bet that Lumileds did throw the Rebel out there for the customers to gnaw on until their better and brighter "Gen X" product is ready for sale. This product, whenever it will come out, will better suit our needs here at the CPF. I think that the Rebel is a nifty little product, and I can think of many nice uses, like for signal lighting for automotive use. Bigger clusters of cheaper and more efficient (because there are more in the cluster to produce the same light) Rebels would make great tail lights, flashers, and even decent reverse lights. Meantime, use the Seoul P4 for headlights.

I agree that it is not the best compared to Cree and Seoul, but Lumileds tried. Imagine creating a new blue LED die from scratch to compete with Cree's. I heard from many on here the Cree always had superb blue (or was it royal-blue) dies, which are great for white LED lighting. I bet Lumileds tried hard but could not get it quite right to meet the specs of Cree's XR-Es exactly. Cree probably had the upper hand a bit for a while, and they could have lost it (maybe all together since the Q2 bin XR-E was just finally released). I bet Lumileds had a vision that the K2 was the future (higher current handling), and while distracted with this, Cree, with a slight and brief burst of speed, leapfrogged Lumileds. No big deal. No company is a loser. Each brand has a product to suit their purposes (and different customer industry types). Companies can screw up once (or twice) here and there. Maybe you will be surprised later... you never know.

Well, this is how I see things... I always try to think optimistically; it does not hurt to do this, by the way. Just sit back and wait patiently for the right LED to be available. Technology takes time. Poor Lumileds is already feeling the heat. Don't forget that they probably still have to compete against their own design manufactured by other foreign companies (clones and look-a-likes). I wonder if Cree or Seoul will face this problem later on. Hmmm... Anyways, Lumileds will work things out. Every company probably slows down in a race at times and have problems, and each handles these problems differently.

Dang, I need to go. It is way too late here and I have class in the morning. Oops...


-Tony


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## 270winchester (Mar 29, 2007)

yawn. 

back to sleep I go.


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## chris_m (Mar 29, 2007)

Gryloc said:


> Cree probably had the upper hand a bit for a while, and they could have lost it (maybe all together since the Q2 bin XR-E was just finally released).



Not strictly accurate - the Q2 bin has only just been released to consumers. Romour is the Q bins have been out for a while - probably since November when they were originally scheduled - it's just that somebody big has been gobbling them all up.


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## riffraff (Mar 29, 2007)

Gryloc said:


> Its late for me, but maybe area lighting is not the goal of the Rebel LEDs. I keep hearing about these being used for full-color RBG signs, like what you see in the football/basketball/baseball stadiums[...]


Yeah, that's the first thing I thought of...smaller size = higher density = higher resolution screens.


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## Opto-King (Mar 29, 2007)

riffraff said:


> Yeah, that's the first thing I thought of...smaller size = higher density = higher resolution screens.


 
You still have the problem with the heat, the heat sink will be much bigger than the LED it self. Seccond, the LED displays that today are using "normal" PLCC2, 4 and 6 LEDs are working well and to a cost of 5% of the Rebel LED. Just take a look at the soccer games in Italy, the comersial LED signs are using "normal" SMD LEDs.


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## soffiler (Mar 29, 2007)

CM said:


> ...Oh, and saying 300lm/w is "never" going to happen is a strong statement that I think will be proven wrong in due time. It may not happen in the next few months or years but ruling it out absolutely at this point is speculative. BTW, I threw that number out tongue in cheek but since you chose to be argumentative, I thought I should present a counterpoint.


 
I did not intend to be argumentative and I'm sorry if you read it that way. I am an engineer and I deal primarily with facts, NOT speculation. I tried to explain the facts to you, and EngineeringGuy did a nice job in post #86 also. Briefly restated, in order to achieve anything above ~240 lm/W of white light you're going to need the equivalent of a perpetual motion machine. Using your tongue-in-cheek number of 300 lm/W, it means an efficiency of 125% - getting OUT fully 25% more power than you put IN. If you understand the laws of physics and thermodynamics, you know that you can never, and I stress never, get more out than you put in.

Personally, I think the confusion arises because people don't grasp that a lumen is simply a measurement of power. It's called "photopic" power because it is weighted for the response of the human eye. If, on the other hand, (as EngineeringGuy also said) we threw away the word lumen and used "radiometric" power instead, the radiometric units of light are watts. Now you can look at electrical power input in watts, and light output in watts, and immediately see that the ratio cannot exceed 100%.


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## SemiMan (Mar 29, 2007)

"Meantime, use the Seoul P4 for headlights." 

- Automotive manufacturers are looking more in the 4,500K for headlights. The Seoul P4 would never pass muster on a car due to the color (and lack of color consistency). Car headlights also cram a lot of light into a small area and hence heat would be a concern. I can't see the P4 standing up to this sort of abuse based on their specifications and some of the posts I have seen here.

" Imagine creating a new blue LED die from scratch to compete with Cree's. "

- This is an interesting point. Lumileds did not really need to create a "new" die to compete with Cree, just like Cree did not need to so much create a new die to get the huge leap in performance. Cree was the first to market with a thin-film blue die used in the XR-E. I understand this is what Lumileds is doing on their new high bright products. From what I understand, neither of them pioneered this technology, OSRAM did with their AlInGaP (red, yellow) LEDS several years ago. Since OSRAM and Cree have a close relationship, I expect that Cree was given access to this patent a while ago? Someone posted recently about Lumileds and OSRAM cross licensing patents. I wonder if that influenced this recent product release?

I did just have a great thought! I don't know about anyone else, but the prices for the XR-E's have not been exactly cheap. Perhaps with the new Lumileds parts coming out, we will finally be able to get Cree XR-Es at a better price. Now that would be a change from the past when we were hoping for competition to Lumileds to get their prices down! I can still remember paying $10+ for a 20 lumen part.

Someone also asked what the goniometer/spectrophotometer would do. While this would give spectrum plots like Newbie provides, more importantly, it would give x-y (angular) beam plots. As opposed to beamshots which are impossible to compare and given the way cameras are made, almost impossible to get a linear response, these would show the exact candela measurements at every angle that the beam emits from the flashlight. This is how lighting fixtures are measured.

Semiman


Semiman


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## CM (Mar 29, 2007)

soffiler said:


> I did not intend to be argumentative and I'm sorry if you read it that way. I am an engineer and I deal primarily with facts, NOT speculation. I tried to explain the facts to you, and EngineeringGuy did a nice job in post #86 also. Briefly restated, in order to achieve anything above ~240 lm/W of white light you're going to need the equivalent of a perpetual motion machine. Using your tongue-in-cheek number of 300 lm/W, it means an efficiency of 125% - getting OUT fully 25% more power than you put IN. If you understand the laws of physics and thermodynamics, you know that you can never, and I stress never, get more out than you put in.
> 
> Personally, I think the confusion arises because people don't grasp that a lumen is simply a measurement of power. It's called "photopic" power because it is weighted for the response of the human eye. If, on the other hand, (as EngineeringGuy also said) we threw away the word lumen and used "radiometric" power instead, the radiometric units of light are watts. Now you can look at electrical power input in watts, and light output in watts, and immediately see that the ratio cannot exceed 100%.




Sorry, I need to correct my statement above. I was thinking of the marketing number Seoul uses which is 240lm but achieved at 1A. You and engineeringguy are correct. My typing was much faster in this case than my thinking was :green: 

However, I still say the Rebel is an attempt to make news out of nothing.


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## Kinnza (Mar 29, 2007)

I believe the Rebel is intended to be the "cheap" LED in the future LML portfolio. Hopefully, LML will release along this year a "high perfomance" LED to compete with CREEs. In this scenario, the Rebel would compete with the XR-C.

This mean the Rebel isnt the part flasholics was waiting from LML. Not only for perfomance, but for mounting specifications. The Rebel's optical axis isnt refered to the ceramic base, but to two references points in it (cathode contact and a hole in one corner). So centering this LED in a reflector may be a PITA.

I has another concern about if its possible to wire the Rebel from top, using the electrical paths over the ceramic base. Has anybody with samples tried it?

About the theoretical photometric efficacy of white light, 240lm/w (emitted watt) is a bit restrictive. Current photometric efficacy of white LEDs are between 260 to 330lm/w. Reducing color rendering for application were it isnt important, allows to design white LEDs with 400lm/w, by doing it with RGB instead of using phospors (and their implied conversion losses). Although RGB solutions has currently several tech problems, potentially it can reach 400lm/w at 100% eff (wich is really far). Obviously, it will take a long time, but i believe white LEDs with 350-380lm/w (consumed) are possible, and probably ill see them in action.


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## PhotonFanatic (Mar 29, 2007)

The Rebel, especially in the higher flux bins, which aren't even listed on Future's website, will be great for what it is--a reflow solderable, high junction temperature, small form factor LED, but it isn't what will make life sweet and easy for CPFers. 

What we need is the Gen-X and 200 lumens at 700 mA.


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## soffiler (Mar 29, 2007)

Kinnza said:


> ...About the theoretical photometric efficacy of white light, 240lm/w (emitted watt) is a bit restrictive. Current photometric efficacy of white LEDs are between 260 to 330lm/w.Reducing color rendering for application were it isnt important, allows to design white LEDs with 400lm/w, by doing it with RGB instead of using phospors...


 
Hi Kinnza:

This is the first I've heard of a conversion factor for WHITE LED's (blue with yellow phosphor) that exceeds the ballpark of 240 lm/W(emitted). Likewise, the numbers I've heard for RGB tend to be around 270 lm/W(emitted). I can see where the RGB number could be tweaked if you stretch your definition of white and let CRI drop, but 400 lm/W seems like a mighty stretch. I'd like to learn more... got any references?


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## Mike Painter (Mar 29, 2007)

soffiler said:


> I did not intend to be argumentative and I'm sorry if you read it that way. I am an engineer and I deal primarily with facts, NOT speculation. I tried to explain the facts to you, and EngineeringGuy did a nice job in post #86 also. Briefly restated, in order to achieve anything above ~240 lm/W of white light you're going to need the equivalent of a perpetual motion machine. Using your tongue-in-cheek number of 300 lm/W, it means an efficiency of 125% - getting OUT fully 25% more power than you put IN. If you understand the laws of physics and thermodynamics, you know that you can never, and I stress never, get more out than you put in.
> 
> Personally, I think the confusion arises because people don't grasp that a lumen is simply a measurement of power. It's called "photopic" power because it is weighted for the response of the human eye. If, on the other hand, (as EngineeringGuy also said) we threw away the word lumen and used "radiometric" power instead, the radiometric units of light are watts. Now you can look at electrical power input in watts, and light output in watts, and immediately see that the ratio cannot exceed 100%.



You seem to be saying that 240 lumen is about equal to 1 watt.
It has been demonstrated that modifying the *shape* of the surface of a LED with concentric rings can imorove light output 7X This is because less than 2% of the available light in the LED gets out. "Light" is emitted through out the LED and little of it reaches teh surface. 
If your definition is correct this means that a LED can be about 50x smaller and emit the same light if properly designed.

I've posted references a couple times and should have kept them. I don't have time today to find them again but, and sadly, because of the volume "nano-holes" will lead you to it.


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## 2xTrinity (Mar 29, 2007)

soffiler said:


> Hi Kinnza:
> 
> This is the first I've heard of a conversion factor for WHITE LED's (blue with yellow phosphor) that exceeds the ballpark of 240 lm/W(emitted). Likewise, the numbers I've heard for RGB tend to be around 270 lm/W(emitted). I can see where the RGB number could be tweaked if you stretch your definition of white and let CRI drop, but 400 lm/W seems like a mighty stretch. I'd like to learn more... got any references?


Well, I think the 330lm refers to the current Phosphor LEDs that that don't have a lot of red, and tend to have slightly "yellow-green" tint. Not using any scientific reference, but just looking at the luminosity function graph on wikipedia and some LEDs I have around, it seems like 400 lm/W(radiated) would be possible using a slightly greenish blue LED (about 500nm), a yellow-green LED (555nm -peak on the graph), and a red-orange LED (620nm) would make something that looks reasonably white, with a bit of a tint. Holding up LEDs at approximately those wavelengths looks pretty reasonble to me to use for something like a flashlight, or street lighting where CRI isn't crucial.


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## soffiler (Mar 29, 2007)

Mike Painter said:


> You seem to be saying that 240 lumen is about equal to 1 watt...


 
Let's be clear that is emitted watts, as Kinnza pointed out. This side of the equation has nothing to do with how much electrical power you supply on the input side. This is a conversion on the output side that compares photopic power (tied to the sensitivity of the human eye, which varies substantially with wavelength) versus radiometric power (which is independent of wavelength).

The conversion factor reaches a peak at 555 nm wavelength, and at this point it is an impressive-sounding 683 lm/W(emitted). However, that's a yellowish-green color, nothing like white, not very useful for illumination purposes, with a color rendering index of zero.

Kinnza also said you could go a lot higher than my stated 240 lm/W(emitted) depending on how you mix your "white". The typical wavelengths of Red, Blue, and Green (RGB) which are mixed to get a reasonable approximation of white will get you more like 270 lm/W(emitted). Kinnza has suggested that if you monkey around with your choices of wavelength for R, and G (most likely using something close to 555 nm for Green), and B, you can still get something more or less recognizable as white (at reduced CRI) and greatly exceed my stated 270 lm/W.


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## Kinnza (Mar 29, 2007)

soffiler said:


> Hi Kinnza:
> 
> This is the first I've heard of a conversion factor for WHITE LED's (blue with yellow phosphor) that exceeds the ballpark of 240 lm/W(emitted). Likewise, the numbers I've heard for RGB tend to be around 270 lm/W(emitted). I can see where the RGB number could be tweaked if you stretch your definition of white and let CRI drop, but 400 lm/W seems like a mighty stretch. I'd like to learn more... got any references?



Yes, blue with yellow phosphor white LEDs have their maximum LER (Luminous Efficacy of Radiation=lm per emited watt) at about 240lm/w, with current phosphor technologies. Although perhaps its possible to increase it a bit by improving phosphors efficiency, or selecting emission spectra with low color rendering. The 240lm/w figure is achieved by reducing the theoretical good rendering white spectra (~330lm/w) by 25% of losses at phosphors. Either reducing this losses or selecting spectra about 400lm/w (greenish white for applications without color renderings constrains) potentially could achieve white sources over 240lm/w (at 100% wall plug efficiency).

But RGB solutions with 3 or 4 chips was theorized long ago as capable to offer higher efficiencies, due to both no phosphor losses and emission spectra exceding 330lm/w. In fact, while seeking for some article showing it, i realized that the 400lm/w figure comes from a high CRI (>80) white spectra, and that 435lm/w spectra (CRI=40) is possible.

Read the article called "Symulation analysis of white LED spectra and color rendering" at the "CIE Expert Symposium on LED light sources" (Pdf).

There is a ilustrated presentation about same topic from Everfine. 

In the page 20 of the 2001 OIDA roadmap 
there is a example of a 399lm/w RGB spectra with CRI=80.

More generally, at "WWW.LIGHTEMITTINGDIODES.ORG" you can found more info. Specially, this two pics:











To finish coming back to topic, anybody has wired the Rebel from top?


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## evan9162 (Mar 29, 2007)

The entire top of the device is covered in the same silicone that the optic dome is made from - this prevents soldering to the top contact.

See page 12 of this document (Luxeon Rebel assembly and handling):

http://www.luxeon.com/pdfs/AB32.pdf


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## niemidc (Mar 30, 2007)

I'd have to say that the Rebel may be totally not what flashlight modders are looking for, yet be an enormous success. For every bin "Q2" CREE sold to you guys, there may be 10,000 55 lumen/watt Rebels sold for use in things that look nothing like a flashlight. Try to keep this in perspective.

I'd also say that while 240 lumens/watt (let alone 300) is pretty far away, long before we reach that point most of the lighting industry will have been totally revolutionized. Think not just about how much light you can get from a given amount of power, but also how much light you can get with a certain amount of heat dissipation. As you approach 50% overall energy efficiency you start to get the ability to pack a lot of light in a very small space. That opens up applications that have never existed before.

Picture this for starters: replace every one of the dozens of incandescent light bulbs in your car with LEDs you never have to replace. It's doable now, and very close to economical when you consider you can dispense with the sockets too.

Next picture a few Rebels (or similarly small surface mount LEDs) in series covered by a diffuser on a tiny circuit board that emerges from a standard light bulb base, maybe twice the cost of a compact fluorescent but no mercury, unbreakable, 5x the life, higher efficiency, better color rendering, and smaller than a halogen, fitting anywhere you like. Then, get rid of the silly old-fashioned base and design this into the lamp, as there's no need to ever replace the bulb. Looks nothing like a flashlight, and totally uninteresting to many of you, but it would change the world in a very big way. And this is happening right now before your eyes.

Think outside the flashlight.


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## PhantomPhoton (Mar 30, 2007)

niemidc said:


> Think outside the flashlight.



*Never!*

:lolsign:

It's hard to say right now how well these rebels will do, in flashlights or otherwise. But I think it is safe to say this particular LED isn't the part "we" have been waiting for. But I wouldn't put it past some crazy people here to make decent use of them in portable lighting anyway.


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## TorchBoy (Mar 30, 2007)

chris_m said:


> Not strictly accurate - the Q2 bin has only just been released to consumers. Romour is the Q bins have been out for a while - probably since November when they were originally scheduled - it's just that somebody big has been gobbling them all up.


Ooh, is that a sniff of a conspiracy? Who could it be?  
 



soffiler said:


> Briefly restated, in order to achieve anything above ~240 lm/W of white light you're going to need the equivalent of a perpetual motion machine. Using your tongue-in-cheek number of 300 lm/W, it means an efficiency of 125% - getting OUT fully 25% more power than you put IN. If you understand the laws of physics and thermodynamics, you know that you can never, and I stress never, get more out than you put in.
> 
> Personally, I think the confusion arises because people don't grasp that a lumen is simply a measurement of power. It's called "photopic" power because it is weighted for the response of the human eye. If, on the other hand, (as EngineeringGuy also said) we threw away the word lumen and used "radiometric" power instead, the radiometric units of light are watts. Now you can look at electrical power input in watts, and light output in watts, and immediately see that the ratio cannot exceed 100%.


Yes, there is a bit of confusion here. I don't put *any* electrical energy into a candle when I light it or when it's burning. So by your definition its efficiency is, um, infinite. Hey, that's more than 100%! 

It's obvious we *can* have more than 100% for the ratio of output light energy to input *electrical* energy, so I have to side with CM (even though he thinks he was mistaken) and say it's not inconceivable that we could have 300 lumens per watt of input electrical energy in a future roughly-LED-like device. I know very well that it wouldn't exceed 242.5 lm/W *total* input energy if you stayed with an ideal white wide-band spectrum.

:touche: 

Either way, it's not going to be a Rebel. Like niemidc said, things will have changed big time by then.

Cheers.


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## soffiler (Mar 30, 2007)

TorchBoy said:



> ...Yes, there is a bit of confusion here. I don't put *any* electrical energy into a candle when I light it or when it's burning. So by your definition its efficiency is, um, infinite. Hey, that's more than 100%!
> 
> It's obvious we *can* have more than 100% for the ratio of output light energy to input *electrical* energy, so I have to side with CM (even though he thinks he was mistaken) and say it's not inconceivable that we could have 300 lumens per watt of input electrical energy in a future roughly-LED-like device. I know very well that it wouldn't exceed 242.5 lm/W *total* input energy if you stayed with an ideal white wide-band spectrum...


 
Come on, Torchboy... the word "electrical" creeps in because we are talking about devices that run purely on electrical power, obviously. A candle doesn't run on electricity. Please don't twist my words around. A candle's energy source is stored in its chemical composition, just like (for example) gasoline. Nobody's running around saying their car's efficiency is infinite, are they?

Hey, Kinnza - superb post! I am off to do my homework...


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## TORCH_BOY (Mar 30, 2007)

Just when I got my Cree, its time to mod my lights again


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## snakebite (Mar 30, 2007)

think about a panel full of these covered with a difuser installed behind your new 50" lcd tv display.


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## Doug S (Mar 30, 2007)

Kinnza: A big thanks for the links to some excellent references. I may not have time to plow through all 101 pages of the one you have linked below but I am thinking that perhaps you meant to direct our attention to page 24 vs the 20 that you reference below.



Kinnza said:


> In the page 20 of the 2001 OIDA roadmap
> there is a example of a 399lm/w RGB spectra with CRI=80.


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## SemiMan (Mar 30, 2007)

Would it be asked too much to get this thread back to discussing the REBEL and not lumens per watt and theoretical limits which I am sure has been discussed a hundred times on this board? Where is a moderator when you need one.... ;-)


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## EngineeringGuy (Mar 30, 2007)

Just an FYI... the 80 lumen parts are "out there". Though they may not be abvailable unless you have enough clout with Future to get them. Plus you have to buy them by the reel (1000 pcs). I don't have them yet, but soon I will. Before anyone asks, no I can't sell any. My company is using them for R&D purposes. I will post any output figures I measure in our calibrated 1m integrating sphere though.


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## metalhed (Mar 30, 2007)

SemiMan said:


> Would it be asked too much to get this thread back to discussing the REBEL and not lumens per watt and theoretical limits which I am sure has been discussed a hundred times on this board? Where is a moderator when you need one.... ;-)



I'll try... 

I received and posted this press release today. Not much real info, but apparently Quantum Lighting of Malaysia thinks that the new Rebel is suitable for portable lighting applications like flashlights.

Quantum Lighting to Introduce Lumileds Rebel-Powered Flashlights and Headlights

I don't have any product photos yet, but I'll try to follow up with Quantum and see if I can get an image or three to share...may have to wait until after the debut at the trade show first, tho'.


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## TorchBoy (Mar 30, 2007)

soffiler said:


> Come on, Torchboy... the word "electrical" creeps in because we are talking about devices that run purely on electrical power, obviously. A candle doesn't run on electricity. Please don't twist my words around. A candle's energy source is stored in its chemical composition, just like (for example) gasoline. Nobody's running around saying their car's efficiency is infinite, are they?





SemiMan said:


> Would it be asked too much to get this thread back to discussing the REBEL and not lumens per watt and theoretical limits which I am sure has been discussed a hundred times on this board? Where is a moderator when you need one.... ;-)


Yes, I acknowledge the Rebel, like all present-day production LEDs, produces its light entirely from *electrical* energy. But I also acknowledge that electricity is not the only way to produce light, or drive around.  :lolsign:


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## Brlux (Apr 18, 2007)

I have been playing with some Luxeon Rebels and thought I would share my thoughts and observations. 



I was initially thinking of waiting till mid summer for the neutral white’s to come out as I don’t much care for bluish LED’s. But curiosity got to me and I decided to go ahead and order some cool whites to play around with. I am very impressed with the tint of the cool whites. They are not the nasty blue that I was expecting but instead the tint is actually about what I was expecting the neutral whites to be. I am now even more curious to see how the neutral whites come out. The LED dome is not a hard epoxy like the other Luxeon products but it is not as soft as the SSC P4’s and it doesn’t seem to attract dust and lint like the SSC P4’s do. 



I was able to do some basic hand soldering of them for my initial testing and playing around. I took a piece of copper sheet pre tined the spot on the sheet and the back of the Rebel and then using some tweezers I was able to place the Rebel after I had heated up the copper sheet with the soldering iron next to where I was placed the Rebel. I placed it so that it was half way hanging off the copper sheet and then I was able to solder small wires to the + - pads. I have also laid out some PC boards and had great success with the toaster oven method and solder paste. 



While they may not fit very well into the segment of the CPF community that likes to mod and upgrade their existing flashlights, I think they will serve other very useful purposes like home/structural lighting and who knows maybe we will wet see a flashlight or two use this LED.


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## moon lander (Apr 18, 2007)

Brlux said:


> I have been playing with some Luxeon Rebels and thought I would share my thoughts and observations.
> 
> 
> 
> ...




you were able to hand solder these? please tell us more! did it require special tools? did you destroy any in the process? i think reflow soldering is what is keeping most of us from buying a bunch of them. at $2 each for 95 lumens, this is a hell of a deal. the reason i like them isnt size, its lumens per dollar.


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## Brlux (Apr 18, 2007)

The hand soldering was just as described I heated up a Copper sheet with the soldering iron, once it was hot enough to melt the solder in the pre tined location I placed the side of the LED with the heat pad (pre tined) on the copper sheet. It was not an ideal setup for using the led, a 1" square copper sheet with a very small led halfway hanging off. But it is easily doable with moderate soldering skills and equipment and alows you to be able to experiment with and try them out. I like them and think they are great for LED area lighting due to the incredable lumen per dollar value.


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## Robocop (Apr 21, 2007)

After reading many searched threads on CPF it seems the general opinion of this Rebel design is not what we were hoping for. It appears that this is better for area lighting such as landscape or home lighting applications...is this the general opinion ??

If it is designed for other applications it makes me curious as to where Lumileds makes most of their profits from.....does anyone care to guess if they are more involved in handheld flashlights or do they actually cater more to area or landscape lighting?

For a very long time I was not even aware of any other players in the game and thought Lumileds made the only luxeons available.....It seems to me that they simply may have been caught by suprise and rushed to get something out to get them noticed again......having said that I am curious if they intended for this new Rebel to be used in flashlights. It seems like to me that maybe this new emitter was not even intended for the CPF crowd and if it was they seem to have failed to impress many of us with first impressions.


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## yellow (Apr 21, 2007)

> It seems to me that they simply may have been caught by suprise and rushed to get something out to get them noticed again


+1 on that. 
Seems to me (I dislike the rebel and its before and after marketing claims), that already happened with the K2 and never stopped from then on.

I would really like to see a sheet with the "intended" application. 
Something where placing, soldering and at the same time fixing the slug to a heatsink is shown.


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## kanarie (Apr 21, 2007)

-1 on that :
The Rebel is meant for a total different market (LCD displays etc.)


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## SemiMan (Apr 22, 2007)

yellow said:


> +1 on that.
> Seems to me (I dislike the rebel and its before and after marketing claims), that already happened with the K2 and never stopped from then on.
> 
> I would really like to see a sheet with the "intended" application.
> Something where placing, soldering and at the same time fixing the slug to a heatsink is shown.



For modern high volume production, the REBEL is probably the easiest part on the market to use. Pain in the *** to hand prototype, but that does not drive the market. It would be very easy to mount these on a small metal core board.

The intended application is anywhere you need cheap LED lumens from what I can tell. The package is not a detriment to any one making anything in volume.


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## moon lander (Apr 22, 2007)

it looks like people have been soldering the heat pad to their heatsinks, is that better or worse than using thermal epoxy like Arctic Alumina? seems like you would have to use the epoxy if your heatsink is aluminum and not copper.


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## TorchBoy (Apr 22, 2007)

SemiMan said:


> For modern high volume production, the REBEL is probably the easiest part on the market to use. Pain in the *** to hand prototype, but that does not drive the market. It would be very easy to mount these on a small metal core board.
> 
> The intended application is anywhere you need cheap LED lumens from what I can tell. The package is not a detriment to any one making anything in volume.


I think I agree with that. Contentious issues, perhaps, but it arguably fits it with Lumileds' more long-sightedness in tactics, going for high power handling rather than efficiency (K2), and price per lumen and ease of use for industry (Rebel).


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## orbital (May 14, 2007)

.

Quantum will be one of the first to use the Luxeon Rebel.

Some possible lights for the future. Lots to check out.....

http://quantumlight.com.hk/flashversion_new/product.htm

.


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## TorchBoy (May 14, 2007)

orbital said:


> http://quantumlight.com.hk/flashversion_new/product.htm


Gotta love the Mystery Meat navigation. *NOT!*


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## orbital (May 15, 2007)

TorchBoy said:


> Gotta love the Mystery Meat navigation. *NOT!*



Hmmm, is there a redirect issue?

,


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## Blindasabat (May 15, 2007)

How do you know that? All I get is a page of what look like old lights using Luxeon LEDs. Is the new stuff hidden somewhere or am I having site problems?


orbital said:


> Quantum will be one of the first to use the Luxeon Rebel.
> Some possible lights for the future. Lots to check out.....
> http://quantumlight.com.hk/flashversion_new/product.htm


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## orbital (May 15, 2007)

Blindasabat said:


> How do you know that? All I get is a page of what look like old lights using Luxeon LEDs. Is the new stuff hidden somewhere or am I having site problems?



My wording as 'possible' lights is key. 
Like other lights such as Ultrafire, with adapting CREEs was fairly seemless.

http://flashlightnews.org/story719.shtml


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## TorchBoy (May 15, 2007)

Orbital, your web site still sucks. Get your mystery meat nav sorted.


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## orbital (May 15, 2007)

.

TorchBoy, what the hell are you talking about, it's not my website.

.


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## frank777 (May 15, 2007)

Same thing that happend to the Nichia 100 lm/watt that was supposed to be available last year....

http://www.eetimes.com/showArticle.jhtml?articleID=181503227


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## TorchBoy (May 16, 2007)

orbital said:


> TorchBoy, what the hell are you talking about, it's not my website.


In that case your mystery links suck. What was the point? :thumbsdow


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## orbital (May 16, 2007)

orbital said:


> 360 views, w/ integrated ceramic, overall layout,
> 
> http://www.lumileds.com/products/line.cfm?lineId=19
> 
> ...



That's right, I was the first to post this link on 03-27-2007, in this tread. :thumbsup:


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## nanotech17 (May 16, 2007)

imagine solitaire drop in with Luxeon Rebel :devil:


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## Blindasabat (May 17, 2007)

I was having site problems. I eventually did get to see the page that said Luxeon Rebel lights coming soon or something to that effect.


orbital said:


> My wording as 'possible' lights is key.
> Like other lights such as Ultrafire, with adapting CREEs was fairly seemless.
> http://flashlightnews.org/story719.shtml


I didn't mean it to sound accusational, I apologize if it did sound that way, I was just looking for where the info was.


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## Blindasabat (May 17, 2007)

That would be such a good use of it do to its size. Maybe the drop-ins Lighthound was selling can be retro-fitted to use a Rebel?
Also, I'd like to see the new Inova X1 upgraded to use one as opposed to the lame it one it uses now.


nanotech17 said:


> imagine solitaire drop in with Luxeon Rebel


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