Production CREE XR-E Testing

[milkyspit]

Amazing results and thanks for testing these NewBie!

To show how much less heat these make for a given lumen output let's say the design goal is 80 lumens. You can get that with a typical Luxeon III running at 700 mA. Typical Vf is roughly 3.7 volts so input power would be 2.59 watts. Efficiency is about 10% so you would have to deal with about 2.33 watts of heat.

Now let's do the same thing with a Cree XR-E. You only need about 350 mA. Vf would be around 3.1 volts so power input would be only 1.085 watts, a reduction of 58% compared to using the Lux III. The heat reduction is even more impressive. Since this part is about 25% efficient you would only be dealing with about 0.81 watts of heat, a reduction of 65% compared to the Lux III. In other words, one-third the heat for the same lumen output. :rock:

The good times are just beginning. A few years ago I was waiting patiently until LEDs finally reached or bettered fluorescent tube efficiency. That time has finally arrived. I can hardly wait to see what Cree has in store for us next year!

Jtr, how does one know the efficiency of a given LED? You cited 10% for your LuxIII scenario.

On a semi-related note, I've been building with LuxI S**H for a while now and have noted that there's a VERY noticeable reduction in heat... for example, my M180 builds even after two hours of continuous runtime, generate only lukewarm amounts of heat. As far as light, we're looking (ballpark) at 180 lumens out of the emitters with efficiency around 55 lumens per watt. But how efficient in percentage terms are these emitters as far as light vs. heat? The evidence suggests there must be a marked increase beyond that 10% figure, but how do I quantify?

As far as fluorescents, good riddance! I've long been of a strong ANTI-fluorescent mindset, given that EVERY FLUORESCENT TUBE CONTAINS MERCURY VAPOR! Nasty, nasty, NASTY stuff! And even if the manufacturers don't gloss over this fact (most do), we all know broken fluorescent tubes are most definitely NOT cleaned up in the manner one would treat release of a hazardous chemical... in school classrooms full of children, for example, nobody leaves, the janitor shows up with his dustpan and just sweeps up the glass. Not good!

If high-efficiency LEDs can put the final stake through the heart of fluorescent lighting, then God bless them.

 

[MillerMods]

WOW! Those pics put it into perspective. These XR-E's ROCK!

 

[DragonFlame]

OMG!
The visual difference in output is almost unbelievable !

 

[WAVE_PARTICLE]

LOL! The spill of the CREE is actually brighter than the hotspot of the P1!


WP

 

[jtr1962]

Jtr, how does one know the efficiency of a given LED? You cited 10% for your LuxIII scenario.

I'm assuming a luminous efficacy of around 330 lm/W for the emitted spectrum. I read that this is about right for blue plus YAG phosphor LEDs. While my calculations may not be exact, they are at least in the ballpark.

On a semi-related note, I've been building with LuxI S**H for a while now and have noted that there's a VERY noticeable reduction in heat... for example, my M180 builds even after two hours of continuous runtime, generate only lukewarm amounts of heat. As far as light, we're looking (ballpark) at 180 lumens out of the emitters with efficiency around 55 lumens per watt. But how efficient in percentage terms are these emitters as far as light vs. heat? The evidence suggests there must be a marked increase beyond that 10% figure, but how do I quantify?

55 lm/W would be roughly 17 or 18% efficient. The great thing about efficiency increases is first off you need less power for the same light output. That already means a reduction in heat. Since the LEDs are more efficient in terms of converting power to light, you get a smaller percentage of the power you put in coming out as heat so you win again. That's why your S-bin LuxI's make way less heat than, say, a Q-bin.

As far as fluorescents, good riddance! I've long been of a strong ANTI-fluorescent mindset, given that EVERY FLUORESCENT TUBE CONTAINS MERCURY VAPOR! Nasty, nasty, NASTY stuff! And even if the manufacturers don't gloss over this fact (most do), we all know broken fluorescent tubes are most definitely NOT cleaned up in the manner one would treat release of a hazardous chemical... in school classrooms full of children, for example, nobody leaves, the janitor shows up with his dustpan and just sweeps up the glass. Not good!

If high-efficiency LEDs can put the final stake through the heart of fluorescent lighting, then God bless them.

Believe me, I share your sentiments which is exactly why developments like this make me happy. Although I love everything else about fluorescent lighting I've always hated the hazardous chemicals and the fact that the tubes can shatter just like incandescent bulbs. A highly efficient, unbreakable, pure white (I really hate the yellowish light of incandescent lamps), and very long-lasting light source is what I have long wanted. Finally with the Cree it seems we have that, and it will only get better as time goes on! Now if only Lumileds can get off their collective rearends to release something competitive.

 

[MillerMods]

I quote from here

"The theoretical maximum for any light spectra is 683 lm/W (for 555 nm monochromatic radiation). For white light, the maximum is typically 300 to 350 lm/W (for a traditional fluorescent lamp spectrum).....It has been shown that it is theoretically possible for a RGB white LED to have a maximum of over 400 lm/W, which means that source efficacy of 200 lm/W can be achieved with 50% LED radiant efficiency. This is the rationale for the US Department of Energy's solid-state lighting goal of 200 lm/W."

So 85-95 lm/W will be something close to 21-24% efficient for the Cree XR-E. About the same or better than a high quality flourescent lamp.

I have a good feeling that Cree's development and pricing will generate a huge boost in LED's place in the lighting industry.

 

[Nitroz]

I held the reflector in my hand, over the CREE XR-E and thus it isn't centered, and the photo is at an angle, as the truck was in the way. So, we have the larger reflector I used (so please keep this in mind!), and this is what I saw:

Anyhow, I need to run off to bed, maybe I can put together something tomorrow that is a much more fair comparison.

@%$! *!@# That is amazing. Looking forward to more reports. Nice Work Newb!

 

[CM]

Let me contribute a white wall beam shot (sorry, it's all I got right now)

I built an Aleph 19 with a Wiz2 running the Cree at 690mA on the left. A modified HDS B42 with the brightest U bin I can find is on the right. I estimate the HDS is hitting the LED pretty hard since my runtime tests on it show about 12 minutes on high. It's also comparable to another HDS light that measured over 60 lumens at LSI so this particular light is my "calibrated" source.

The McR-19 in the Aleph is an excellent match to the XR-E. Lots of sidespill but the hot spot has enough intensity to be able to give the light some respectable throw.

 

[MillerMods]

oops, double post.

 

[MillerMods]

I like the 75 degree viewing angle of the Cree. It makes the spill much more useful. A really deep narrow reflector will make one of these XR-E's a real flame thrower! The new AA Mag LED reflector would be a good candidate.

 

[CM]

Finally went ahead and did some quantitative measurements. I have a P2 bin Cree and comparing that to a U bin Lux III, it is 50% brighter. I wish I had access to a sphere but based on what I know about this particular U bin Lux III, the Cree is outputting over 90 lumens easily through the Aleph's sapphire lens which is pretty lossy.

 

[p1fiend]

I held the reflector in my hand, over the CREE XR-E and thus it isn't centered, and the photo is at an angle, as the truck was in the way. So, we have the larger reflector I used (so please keep this in mind!), and this is what I saw:

:huh2:
No Way! That P1 beam shot looks totally wrong. If this was taken at an angle, but close to a garage, the P1 beam should be much bigger and have at least SOME spill to it. What gives?

 

[:)>]

Please tell me that the HD45 could be modded with the Cree's for 2 level light. The beamshot was tremendous even at 450 ma. From the looks of that beamshot, the output at 450 ma is greater than the output of my Lux III HD45 at 900 ma.

Nice.!

-Goatee

 

[AlexGT]

I think the only thing that "gives" is that the Cree is totally OWNING the U bin:goodjob:

:huh2:
No Way! That P1 beam shot looks totally wrong. If this was taken at an angle, but close to a garage, the P1 beam should be much bigger and have at least SOME spill to it. What gives?

 

[p1fiend]

I think the only thing that "gives" is that the Cree is totally OWNING the U bin:goodjob:

There is no way that a P1 beam is a tiny < 1ft x 1ft spot with no spill. Something isn't right with that shot, yet everyone seems incredibly impressed with it.

 

[grapplex]

...

 

[NewBie]

The flood brightness in the CREE is tremendous. Instead of a really "contrasty" hotspot with a weak flood, it has easily as strong of a hotspot, and a very strong flood. It makes for a *very* useful light, that can throw and has a flood beam that is much closer to the hotspot, imagine flood that can be throw. I found it very useful for searching for things.


Anyhow, I got my A19 XR-E, which has a bit of an issue. Within two hours of receiving the package, dat2zip was all over things to get the problem rectified. So, this isn't a good comparision either, as it is, the XR-E is "crippled"

But it has bracketing of the photos, and the reflectors are so close in size, that it takes out the reflector factor-just remember the XR-E is now crippled:

 

[AtomSphere]

P1 got owned! Thanks for the pictures!

 

[Robocop]

Man this new stuff is really advancing pretty quickly.....pretty soon we will all be replacing our coveted U bins as outdated.

Ok not knowing much at all about dome characters and even less about reflectors is there a necessary reason for the actual design of this new Emitter? Would it be possible to place this new design inside the same dome shape as a standard Luxeon III design? I am wondering if this new emitter somehow has to be made into a more flood pattern by design?...Is it simply done because they do not wish to violate some form of copy write design of LumiLeds?

I am wondering if they will offer different viewing angles to better use existing reflectors while maintaining the same output as the new design. It seems a shame that we will have to start all over trying to find a custom made reflector for this new design however Don seems to be doing just that.

I sure do like the idea of using some of the ready available 17mm reflectors and a small host light for this new emitter. Imagine this beast coupled with an Orb NS and direct drive with the much improved efficiency levels.....now that is impressive to say the least.....or one of those slick MillerModded Arc hosts....the possibilities are sure interesting to think about.

 

[BentHeadTX]

It seems a shame that we will have to start all over trying to find a custom made reflector for this new design however Don seems to be doing just that.

I sure do like the idea of using some of the ready available 17mm reflectors and a small host light for this new emitter. Imagine this beast coupled with an Orb NS and direct drive with the much improved efficiency levels.....now that is impressive to say the least.....or one of those slick MillerModded Arc hosts....the possibilities are sure interesting to think about.

The McR17XR reflector? Yeah, I think those will fit in my MillerMods 1.7 watt L1P with an XR-E sitting behind it. 100+ lumens with a basic and 125 lumens with a Q3 bin sounds rather tastey to me.

Don has taken the lead with this so I eagerly await what kind of magic he has planed in the XR series.