# Lumileds uping the ante on the Rebel



## saabluster (Jul 27, 2010)

Of course this is not a revolutionary new offering but more an improvement to the existing line. Still I am impressed to see how well Luxeon is keeping up(passing?) with Cree. 

The Luxeon Rebel ES can deliver 100 lm/W efficacy at the maximum 1A drive current, or luminaire makers can lower the drive current and achieve even greater 125 lm/W efficacy. 
 

Datasheet


Of note is the 1500mA max current capability and what seems to be awfully close to no sag with increasing current. 

I just wish their binning was tighter so you knew better what you were getting.

A little more info.


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## znomit (Jul 27, 2010)

*Re: Luxeon uping the ante on the Rebel*

Nice update

I was going to guess bigger die... but from the product brief:

_Whats new
- Very small optical source size
_
But then the pics...
ES:






Old:


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## Curt R (Jul 27, 2010)

*Re: Luxeon uping the ante on the Rebel*

Thanks for the info, will look into them as a back-up to the Cree in our lights. :wave:

Still waiting for my XM samples, they may have a little problem getting good production quality samples as the 
buildup manufacturing process is different than they have been using on the XP dies. 

Curt


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## saabluster (Jul 28, 2010)

*Re: Luxeon uping the ante on the Rebel*



znomit said:


> Nice update
> 
> I was going to guess bigger die... but from the product brief:
> 
> ...



I thought that was the case when I saw the pics but didn't have the time when I posted to do an in-depth examination. That has a pretty big ramification on the optics used and results seen from use in certain applications. I would much rather have seen them rename it even though it is the same package more like Cree does. It makes it really confusing to call two products by the same name.:shakehead 

With the larger die size in mind I rescind the remark about them maybe passing up Cree as that was based more on the assumption/hope that the die was still 1mmx1mm. So now Lumileds has an XP-G competitor. Sort of.


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## LumenHound (Jul 28, 2010)

*Re: Luxeon uping the ante on the Rebel*

Lumileds who???

I know, I know....

It's amazing how things have changed in the last few years.
I remember when we were happy to pay $30.00 for a primo UWOK bin star.


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## evilc66 (Jul 28, 2010)

*Re: Luxeon uping the ante on the Rebel*

Hopefully it holds true in real life, but the datasheet claims very little difference in lumen output between cool and neutral white (around 5lm at 350mA and 700mA, 10lm at 1000mA). That's pretty interesting.


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## blasterman (Jul 28, 2010)

*Re: Luxeon uping the ante on the Rebel*

From the datasheet:

*"Typical CRI for Neutral-White is 65, Cool-White is 70."*

Which didn't make sense until I went to Lumileds site and found what I believe is a more accurate chart:

http://www.philipslumileds.com/products/luxeon-rebel/luxeon-rebel-white

So, the higher flux neutrals take a big hit in terms of CRI - no surprise there. If you want more efficiency at lower CCTs yellow/amber gets sacrificed. 

If I'm reading this chart right the best ES takes a serious back seat to the XP-G in true neutral white flavors. This was surprising. However, the higher CCT values keep up pretty good.


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## HarryN (Jul 29, 2010)

*Re: Luxeon uping the ante on the Rebel*



saabluster said:


> I thought that was the case when I saw the pics but didn't have the time when I posted to do an in-depth examination. That has a pretty big ramification on the optics used and results seen from use in certain applications. I would much rather have seen them rename it even though it is the same package more like Cree does. It makes it really confusing to call two products by the same name.:shakehead
> 
> With the larger die size in mind I rescind the remark about them maybe passing up Cree as that was based more on the assumption/hope that the die was still 1mmx1mm. So now Lumileds has an XP-G competitor. Sort of.



I have been fooled before by assuming die size changes when the actual change can be simply optical properties of the package as a whole. I am not saying the new die is larger or not, but in the end, what matters are the results.

I got a little nervous when you reminded me that this new part could results a different radiation pattern, so I needed to double check it. (on paper for now, later of course with real parts)

I looked at the data sheet spatial radiation pattern (data sheets, typically page 18 or 19) from the older Rebel parts of various CRI types, colors, and the newer upgraded part. I compared 5 points from each of them and they are virtually a match, "indicating" that these will be really close in focus results.

Philips Lumileds has such a large base of customers and related firms banking on being able to use any Rebel in any optic interchangeably, that I can't imagine them not engineering this part to optically match the others. Keep in mind that these are the guys that took a beating in the past for making a very small change to a dimension in the Lux III that was not even an engineered spec dimension.

OK, yes, I am still hoping that it is the same, not proven, although their data sheets are usually pretty darn accurate.

BTW - if you want tighter binning of a CCT or CRI, just look a little closer at the white p/n selection. Some of those are simply tighter binned versions of the more generic white parts. There is a slight price premium for them, but it is relatively small, and much less painful to purchase an "off the shelf" p/n than the old method of being on the hunt for a specific bin.


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## znomit (Jul 29, 2010)

*Re: Luxeon uping the ante on the Rebel*



HarryN said:


> I looked at the data sheet spatial radiation pattern (data sheets, typically page 18 or 19) from the older Rebel parts of various CRI types, colors, and the newer upgraded part. I compared 5 points from each of them and they are virtually a match, "indicating" that these will be really close in focus results.



Check out XPG/XPE datasheets, different dies, identical spatial radiation patterns but the smaller die XPE throws much better.


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## IMSabbel (Jul 29, 2010)

*Re: Luxeon uping the ante on the Rebel*

Still, its nice to see that the competition is not dead.

While not world-shaking, it still is a huge step forwards in light output per device.


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## Illum (Jul 29, 2010)

*Re: Luxeon uping the ante on the Rebel*

um...Luxeon is a product series, not the name of a company:thinking:

Luxeon line died long ago. "Luxeon uping the ante on the Rebel" would be analogous to "XPE uping the ante on the XRE"

Unless you meant it as above I think it would be more correct to consider "Lumileds uping the ante on the Rebel"



znomit said:


> But then the pics...
> ES:
> 
> 
> ...



Considering the small footprint of the rebel, I wonder if the ESD diode would now be more susceptible to solder damage now that it is within almost direct contact to the soldering points


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## fyrstormer (Jul 29, 2010)

*Re: Luxeon uping the ante on the Rebel*



HarryN said:


> I have been fooled before by assuming die size changes when the actual change can be simply optical properties of the package as a whole. I am not saying the new die is larger or not, but in the end, what matters are the results.
> 
> I got a little nervous when you reminded me that this new part could results a different radiation pattern, so I needed to double check it. (on paper for now, later of course with real parts)


Focusing optics only work perfectly on light emitted from the exact focal point. Larger dies are by definition less point-like, in that more of the light comes from off-center, and from further off-center. Nothing anyone does can change this. There's no law of physics that allows Philips to skirt around the problem that the minimum divergence of a focused beam from a larger die is going to be wider than from a smaller die.

That being said, I don't care about having a perfectly-collimated beam or really anything close to it, as I rarely run into situations where I really need to be able to pinpoint individual rocks on the Moon from my backyard, so it doesn't affect me any. Most likely what Philips is banking on is that most of their customers won't care either, at least not regarding whatever products earn them most of their money, and for the products that _do_ actually _need_ smaller dies, they can just buy the top-of-the-line emitters to get the flux they need. As long as the radiation pattern from the center of the die is the same from one model to the next, the die size shouldn't make any noticeable difference in most applications.


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## bshanahan14rulz (Jul 29, 2010)

*Re: Luxeon uping the ante on the Rebel*

ESD is on the top side, it is that little block outside the dome.

Solder pads are on the bottom of the device.

From the 3D view:
Also, possible barcode on the bottom will make it easier to determine bins, with a little bit of work. Unlike the guessing game of Cree LEDs...
Die looks bigger, has more internal connect points, 36. 

Ok, you got me interested.

Oh, and pushing that Vf lower? highest voltage bin is 3.25-3.5V, lowest is 2.5-2.75, at 700mA


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## HarryN (Jul 29, 2010)

*Re: Luxeon uping the ante on the Rebel*

I wonder if what we are thinking is a "larger die" is actually a different phos approach. Lumileds has been working on what they called "Lumeric" or something like this for a while, which is actually molding the phos into a ceramic plate. The idea was to test each die for output, and match it to a "Lumeric" ceramic cover to obtain the same final color bin result.

This is just a guess, but it would make more sense than Lumileds increasing their die size.

In order for this to work, I would think you also need to cover the edges, which would make the die "appear" to be bigger in the package, but may or may not affect what the emission looks like.

In their early days of getting into the power led business, Cree didn't cover the sides of their die with phos. The very narrow blue ring of light emitted from the sides was nearly un noticed - until you put it in a reflector. The resulting beam color was an ugly cloudy mess. Obviously, they have come a long way.


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## blasterman (Jul 29, 2010)

*Re: Luxeon uping the ante on the Rebel*



> As long as the radiation pattern from the center of the die is the same from one model to the next, the die size shouldn't make any noticeable difference in most applications.


 
Most likely scenario. Changes in the LED package or dimensions are typically done to decrease fab costs and be transparent to customers. 

The Rebel line seems more focused on OEMs that use large volumes of emitters and need something with a bit more performance than SMD but not state of the art 3watt performance. 

Given the choice of unified lumens over a CCT range it's pretty obvious who the customer base is.


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## HarryN (Jul 29, 2010)

*Re: Luxeon uping the ante on the Rebel*



blasterman said:


> Most likely scenario. Changes in the LED package or dimensions are typically done to decrease fab costs and be transparent to customers.
> 
> The Rebel line seems more focused on OEMs that use large volumes of emitters and need something with a bit more performance than SMD but not state of the art 3watt performance.
> 
> Given the choice of unified lumens over a CCT range it's pretty obvious who the customer base is.



Really? 19 p/ns for "white" (not including binning) plus 7 p/ns for "colors", not including binning versions. That covers a pretty large range of customers.

I agree that they most likely are focused on large OEM type customers, just like everyone else is. That is why LEDs are so cheap now.


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## zzonbi (Jul 30, 2010)

*rebel ES*

different (larger) die

although it trails the cool white xpg, Vf and thermal drift seem lower, also the beam a tad tighter

300lm+-6.5% 1A 25C 3.1V 4100K CRI>60

I like the lack of wires, hope the tales about K2 ruggedness are true here (>70% lm <50kh, 1A, 135C)


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## MichaelW (Jul 30, 2010)

*All hail the big Rebel!*

How else exactly would they increase the maximum drive current to 1.5 A without an increase in die size.
The thermal pad looks unchanged. The thermal resistance is less, 6 vs. 10.
and the 'dot grid' is 5x5 instead of 4x4 

I was looking at the Rebel & Rebel ES datasheets a month or so ago, and they said 700mA maximum drive current for regular Rebel, and 1,000mA for Rebel ES. I went and looked at older datasheets, and the Rebel WAS rated to 1,000mA. So, a retrograde derating of drive current?


Regarding the CRI of the new Rebel ES, is it possible that someone made an error?
Lumileds used to always order things in their PDFs cool-white, neutral-white, warm-white. In this PDF, it goes cool-neutral for minimum, then switches to neutral-cool for typical. That does not seem right. 
Also the SPD graph for neutral-white doesn't look like it was compromised to get enhanced output.


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## Black Rose (Jul 30, 2010)

*Re: All hail the big Rebel!*



MichaelW said:


> I was looking at the Rebel & Rebel ES datasheets a month or so ago, and they said 700mA maximum drive current for regular Rebel, and 1,000mA for Rebel ES. I went and looked at older datasheets, and the Rebel WAS rated to 1,000mA. So, a retrograde derating of drive current?


The absolute maximum DC forward current is still listed as 1000 mA.


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## MichaelW (Jul 30, 2010)

*Re: Luxeon uping the ante on the Rebel*

I have a datasheet from last year, and it says 1 amp.
I looked at the datasheets from 1-2 months ago, and it say 700mA for Rebel, 1,000mA for Rebel es

Now the Rebel ES [new] is 1,500mA, and Rebel is back to 1,000mA.


I just want to know if I can get this for my aging Fenix RB100 L2D & P3D.


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## saabluster (Aug 1, 2010)

*Re: Luxeon uping the ante on the Rebel*



Illum said:


> um...Luxeon is a product series, not the name of a company:thinking:
> 
> Luxeon line died long ago. "Luxeon uping the ante on the Rebel" would be analogous to "XPE uping the ante on the XRE"
> 
> Unless you meant it as above I think it would be more correct to consider "Lumileds uping the ante on the Rebel"



Indeed I should have written Lumileds. Change made. Thanks.

I don't know why you say the Luxeon line is dead though as it is clearly plastered all over the new datasheet.


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## saabluster (Aug 1, 2010)

*Re: All hail the big Rebel!*



MichaelW said:


> How else exactly would they increase the maximum drive current to 1.5 A without an increase in die size.



By improving the performance of the die or improvements in the thermal characteristics of the package. Enlarging the die is not the only route to increasing current capability but it is a bit easier at this point since the other two avenues are at a relatively advanced stage.


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## jeffosborne (Aug 5, 2010)

*They're here!*

Each day since this thread appeared, I've been checking the Rebel ES listing at Future Electronics, eager to purchase a few. And just today the listing show both the cool and neutral devices in stock! 2,276 of the neutral whites in stock, it says. I bought 12 of them at $4.85 each. 

I have several 80-lumen per watt Rebel emitters in lights around the house. I'll upgrade some of them to this 125-lumen per watt newbie.

I will be sure to report the BIN received, as it is a roll of the dice on small quantities from Future.

Hooray!
Jeff


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## jeffosborne (Aug 9, 2010)

*ES received, but BIN woes ensued...*

I received 12 Rebel ES emitters today from Future Electronics! I am eager to get 300 lumens from one emitter on a 1-amp budget, especially in neutral white. But the packing list shows a BIN of 'JUL', which does not tell me anything about the parts. The Phillips doc calls out a BIN scheme that does not follow this BIN at all. I wrote to Future and asked them to give me a correct BIN. 
Here's a comparison photo:





The original neutral white Reble to the left, the more recent high-CRI part in the middle, and the new Rebel ES to the right. The ES die looks to be much larger than the other two. I've covered the bottom terminals on one of the ES LEDs with a thin coat of enamel, and will mount it into the Aurora light on the left side, below. I'll be booting an XPE to put it into place. What fun!




Jeff


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## Illum (Aug 9, 2010)

*Re: Luxeon uping the ante on the Rebel*



saabluster said:


> I don't know why you say the Luxeon line is dead though as it is clearly plastered all over the new datasheet.



huh...I recieved word on here that they're discontinuing luxeon 1s...my guess is that information was faulty


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## jeffosborne (Aug 10, 2010)

*received the BIN code...*

The BIN code for the 12 Rebel-ES emitters I received yesterday is:

UTOS

U = 220-240 lumens at 700ma

TO = 4100-4500K at the black body locus 

S = 3.0 - 3.25 Vf

I am happy with this, and hope to fire one up this evening.

Jeff


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## Black Rose (Aug 11, 2010)

*Re: Luxeon uping the ante on the Rebel*



Illum said:


> huh...I recieved word on here that they're discontinuing luxeon 1s...my guess is that information was faulty


Nope, not faulty info. The Luxeon I, III, V, K2, etc have been killed off. 

PhilipsLumileds is still using the Luxeon brand name for their active LEDs (Luxeon Rebel, Luxeon C, Luxeon Flash, Luxeon Altilon)


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## croled (Aug 17, 2010)

New 120lm "old" rebels?:huh:
http://www.futureelectronics.com/en...?ProductID=LXMLPWC10120PHILIPSLUMILEDS1000732


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## saabluster (Aug 17, 2010)

croled said:


> New 120lm "old" rebels?:huh:
> http://www.futureelectronics.com/en...?ProductID=LXMLPWC10120PHILIPSLUMILEDS1000732


That's much more interesting than the new ES. Thanks.


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## jeffosborne (Aug 17, 2010)

But, the newly listed 'old' Rebel is a dollar more than the ES, and a few less lumens per watt! Is it your view, Dr. saabluster, that the smaller die of the 'old' Rebel is an advantage for throw, perhaps? I did notice that the ES I put into the Aurora flashlight has a brighter and slightly larger center spot than the XP-E I removed. Also I love the neutral-white tint of the ES part. Cheers, Jeff


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## saabluster (Aug 17, 2010)

jeffosborne said:


> Is it your view, Dr. saabluster, that the smaller die of the 'old' Rebel is an advantage for throw, perhaps?


Yes that is exactly what I am excited about. I'm tired of all these larger, albeit higher efficiency, LEDs that are going backwards in terms of surface brightness. 



jeffosborne said:


> I did notice that the ES I put into the Aurora flashlight has a brighter and slightly larger center spot than the XP-E I removed. Also I love the neutral-white tint of the ES part. Cheers, Jeff


Did you just use your eye to make the determination that the new ES had a brighter center spot or did you use a light meter? Also when you say "ES" are you referring to this newer large die version? Just want to make sure we are on the same page.


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## croled (Aug 18, 2010)

saabluster said:


> That's much more interesting than the new ES. Thanks.



More interesting is that there is also neutral white 120lm version(cree :wave:

http://www.futureelectronics.com/en...?ProductID=LXMLPWN10120PHILIPSLUMILEDS2000732


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## saabluster (Aug 18, 2010)

croled said:


> More interesting is that there is also neutral white 120lm version(cree :wave:
> 
> http://www.futureelectronics.com/en...?ProductID=LXMLPWN10120PHILIPSLUMILEDS2000732



That is just a match for Cree's Outdoor white XP-E R2 neutral which was introduced at the end of last year. Still if these latest parts from Lumileds(small die) are the real deal they have caught back up with Cree.


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## jeffosborne (Aug 18, 2010)

Here are some photos of the stock SH0030 Aurora light (DX #25490) with it's cool white XP-E Q5, and the same flashlight with the neutral white Rebel ES. I don't have a light meter, but the Rebel seems to be putting out more light overall. Certainly the center spot is larger with the Rebel.




















Cheers,
Jeff


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## saabluster (Aug 18, 2010)

jeffosborne said:


> Here are some photos of the stock SH0030 Aurora light (DX #25490) with it's cool white XP-E Q5, and the same flashlight with the neutral white Rebel ES. I don't have a light meter, but the Rebel seems to be putting out more light overall. Certainly the center spot is larger with the Rebel.
> 
> Cheers,
> Jeff


Well the ES looks lightyears better than the Cree in that back to back. I am wondering though if the ES is not receiving more current than the XP-E due to the type of driver used. It just doesn't seem to add up otherwise as far as intensity is concerned. Thanks for posting the pics.


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## uk_caver (Aug 19, 2010)

*Re: Luxeon uping the ante on the Rebel*



Illum said:


> um...Luxeon is a product series, not the name of a company:thinking:
> 
> Luxeon line died long ago. "Luxeon uping the ante on the Rebel" would be analogous to "XPE uping the ante on the XRE"


Still, Luxeon isn't exactly a dead name - Philips/Lumileds still use it as part of the name for most products, including the Luxeon Rebel.


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## HarryN (Aug 19, 2010)

saabluster said:


> Well the ES looks lightyears better than the Cree in that back to back. I am wondering though if the ES is not receiving more current than the XP-E due to the type of driver used. It just doesn't seem to add up otherwise as far as intensity is concerned. Thanks for posting the pics.



I suspect / am guessing that the thermal droop is less for the rebel, and that is the difference that is showing up. PL has been working hard on this for a while, at least in part because so many of their customers do such a poor job of heat management.

Jeff, thank you for those pictures and the testing.


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## zzonbi (Aug 22, 2010)

Yes, you need to measure currents for the least, before we can cheer.
As is, the luminance seems on par (subject to white balance though), with 2x the q5 flux (they're at r3 now).


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## saabluster (Aug 23, 2010)

HarryN said:


> I suspect / am guessing that the thermal droop is less for the rebel, and that is the difference that is showing up. PL has been working hard on this for a while, at least in part because so many of their customers do such a poor job of heat management.
> 
> Jeff, thank you for those pictures and the testing.


There has been no talk of them ever actually getting that anti-droop tech in production and there is nothing in the data sheets to suggest they are doing anything significantly different in that respect than Cree. Maybe the new pact between Cree and Lumileds will help get this to the market. There was certainly something they were going on about way back when so I don't doubt it is possible but it may have been something either impractical or which required the use of Cree IP to implement. No way for us to know but there was something Cree saw in a patent swap between them.


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## Neondiod (Aug 23, 2010)

That Neutral ES looks warm white to me, compared to the, I assume, cool white XP-E Q5 in the pics.

I wonder why the Rebel doesn't have a larger heat pad? Now it looks like it have 1/3 of it chopped of, or in other words, it could be 50% larger.


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## saabluster (Aug 23, 2010)

Neondiod said:


> I wonder why the Rebel doesn't have a larger heat pad? Now it looks like it have 1/3 of it chopped of, or in other words, it could be 50% larger.


There would be very little if any benefit to making the heat pad larger. The heat does not travel laterally through that ceramic. It would be better to make it thinner or of a material that conducts heat better.


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## HarryN (Aug 23, 2010)

Hi, comparing the ES data sheet (D61) I downloaded in March, to the current version, the die to pad thermal resistance has dropped from 10 C / watt to 6 C / watt. That may not seem like much, but it is a huge gain in practice at these power levels.

Interestingly, the spec Vf has stayed the same, but now is spec at 700ma vs 350ma on the old sheet, indicating an improved efficiency.


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## Gryloc (Aug 23, 2010)

I am now thinking that Lumileds had two separate parts with the name "Rebel ES". I remembered a white Rebel that was guaranteed to be 100lm/W that appeared to have either the same, or slightly better specs than the Rebal 0100 bin. I recall that it was binned at 350mA. I always thought it was a premium Rebel white (it had a smaller CCT range that maxed at 4500K I believe) that used a 1mm^2 die. 

Was this earlier Rebel that was guaranteed to be 100lm/W minimum called the ES for sure, and was it the same part? Was it ever available for sale? If so, that has to add to the confusion of customers that bought this earlier product.

If that old ES was this newer version with a 2mm^2 die, then it was not clear, so were we really waiting ages for this new part? I wonder if names of some parts were swapped because a part failed to come out; done just to save the ES name and/or to make sure something special was released. 

Did I recall things correctly about a different part from the past with the same name? Anyone know what really happened? I am just speculating.

-Tony


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## saabluster (Aug 24, 2010)

HarryN said:


> Hi, comparing the ES data sheet (D61) I downloaded in March, to the current version, the die to pad thermal resistance has dropped from 10 C / watt to 6 C / watt. That may not seem like much, but it is a huge gain in practice at these power levels.
> 
> Interestingly, the spec Vf has stayed the same, but now is spec at 700ma vs 350ma on the old sheet, indicating an improved efficiency.


The lower thermal resistance is a result of the larger die. That said it is not really an improvement over the small die version, as far as surface brightness is concerned, as you will not be able to increase the energy density of this new Rebel part.



Gryloc said:


> I am now thinking that Lumileds had two separate parts with the name "Rebel ES". I remembered a white Rebel that was guaranteed to be 100lm/W that appeared to have either the same, or slightly better specs than the Rebal 0100 bin. I recall that it was binned at 350mA. I always thought it was a premium Rebel white (it had a smaller CCT range that maxed at 4500K I believe) that used a 1mm^2 die.
> 
> Was this earlier Rebel that was guaranteed to be 100lm/W minimum called the ES for sure, and was it the same part? Was it ever available for sale? If so, that has to add to the confusion of customers that bought this earlier product.
> 
> ...



You are correct that they are calling two different LEDs by the same name. It is very annoying and is why I complained about it earlier in this thread. You just don't do that. The easy way to tell is to look for the externally mounted esd diode. The old small die ES did not have that.


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## Black Rose (Aug 24, 2010)

saabluster said:


> You are correct that they are calling two different LEDs by the same name. It is very annoying and is why I complained about it earlier in this thread. You just don't do that. The easy way to tell is to look for the externally mounted esd diode. The old small die ES did not have that.


OK, that's good to know.

I was on the LuxeonStar site the other day and saw that they were listing the Rebel ES as being discontinued, which I thought was odd since I thought it had just shown up.

Very poor product naming.


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## HarryN (Aug 31, 2010)

Hi, I confirmed through Future that the new Rebel ES part is 1.4 x 1.4 mm, vs the "normal" Rebel which is 1 x 1 mm. As you might expect, it is intended to compete with the XP-G in the low CRI marketplace for streetlights.


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## Nil Einne (Aug 31, 2010)

Interesting from the http://www1.futureelectronics.com/FLS-Doc/LuxeonRebelESLaunchFAQ.pdf Philips Rebel ES FAQ:

The new chip is 1.4mm x 1.4mm and is the same size as the Cree XPG chip but delivers better performance in actual operating conditions


As for two parts having the same name?

These parts will remain available for the time being although we expect our customers to focus on the new parts and therefore our marketing materials will emphasize the new parts and reduce visibility of the other LUXEON Rebel ES emitters.


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## saabluster (Sep 1, 2010)

Nil Einne said:


> Interesting from the http://www1.futureelectronics.com/FLS-Doc/LuxeonRebelESLaunchFAQ.pdf Philips Rebel ES FAQ:
> 
> The new chip is 1.4mm x 1.4mm and is the same size as the Cree XPG chip but delivers better performance in actual operating conditions



That is quite a bold statement. It is rather general with nothing to back it up though.


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## HarryN (Sep 2, 2010)

saabluster said:


> That is quite a bold statement. It is rather general with nothing to back it up though.



You are right. I guess it is time to buy some of each of the "typical bin" and send them off to JTR1962 for comparison under real world conditions thermal conditions, not super cooled like some of the testing. I need to buy a few of those Rebel ES parts anyway, and I have some decent bin XP-Gs already.


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## saabluster (Sep 3, 2010)

HarryN said:


> You are right. I guess it is time to buy some of each of the "typical bin" and send them off to JTR1962 for comparison under real world conditions thermal conditions, not super cooled like some of the testing. I need to buy a few of those Rebel ES parts anyway, and I have some decent bin XP-Gs already.



I was thinking the same thing. Hope he has the time. But what aspect of performance are they claiming to be better in? That is the vagueness I was referring to. Color consistency, droop, output, reliability?:shrug:


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## HarryN (Sep 3, 2010)

saabluster said:


> I was thinking the same thing. Hope he has the time. But what aspect of performance are they claiming to be better in? That is the vagueness I was referring to. Color consistency, droop, output, reliability?:shrug:



All good questions. 

As a practical matter
- Both Cree and Lumileds are well known for their reliability. I have no interst in funding or waiting around for a 100K hour test.
- I am not able / willing to fund the purchase of enough LEDs to test color consistency, and since the target market for these is outdoor streetlights, which will have "many" LEDs in it, maybe it doesn't matter?
- Droop and output - JTR can test this, so that is what I am hoping to see a comparison of.

No matter how it comes out, should be fun and informative.


----------



## jeffosborne (Sep 3, 2010)

Good thought HarryN, I too would like to see JTR1962 do his analysis on this part. I have saved and scrutenized his previous LED test reports. Has anyone asked him about this? I read that he has been busy, overheated and distracted with his pedaling lately. I would volunteer test parts. Jeff O.


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## jtr1962 (Sep 3, 2010)

jeffosborne said:


> Good thought HarryN, I too would like to see JTR1962 do his analysis on this part. I have saved and scrutenized his previous LED test reports. Has anyone asked him about this? I read that he has been busy, overheated and distracted with his pedaling lately. I would volunteer test parts.


I will eventually get back to testing. I've taken a break from it these last few months both on account of the heat, and also my desire to take better care of myself. I need to make a regulated thermoelectric hot/cold plate in order to automate any testing of LEDs at various heat sink temperatures. Once that's done, I can easily test LEDs for HarryN at "real-world" temperatures. I had done some testing of that type for him in the past but it was quite tedious trying to stabilize the plate temperature by hand. I'll give a heads up in my lumen testing thread when I've built the regulated temperature plate. It's actually not a terribly hard project by my standards. It's just that a combination of heat and humidity has left me pretty drained. By early October hopefully my normal energy levels should return.


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## MichaelW (Sep 6, 2010)

*Any thoughts?*

Will this large die Rebel be applicable to the PC Amber Rebel?


----------



## HarryN (Sep 11, 2010)

*Re: Any thoughts?*



MichaelW said:


> Will this large die Rebel be applicable to the PC Amber Rebel?



Hi, I don't know what the long term will bring, but the Future Electronics guy I spoke with (Lumileds Lighting specialist) was pretty insistent that the focus of this is on high brightness, 70 CRI outdoor white lighting.

The PC amber LED I saw was pretty bright (for amber) already. How much do you need ?


----------



## MichaelW (Sep 15, 2010)

*Re: Any thoughts?*



HarryN said:


> How much do you need ?


How much you got...
I like low pressure sodium,[efficiency & color] but dislike the highly monochromatic output. [who doesn't]
I am thinking 200 lumens @ 1 amp drive, perfect in large groups for street lights.
Pros: very little light shorter than 530 nanometres-Helps with melatonin, and I think bugs too.
Cons: it may not be trendy enough for hipsters who want to bring daylight realism to night.

Maybe parking garages...


----------



## IMSabbel (Sep 16, 2010)

*Re: Any thoughts?*



MichaelW said:


> How much you got...
> I like low pressure sodium,[efficiency & color] but dislike the highly monochromatic output. [who doesn't]
> I am thinking 200 lumens @ 1 amp drive, perfect in large groups for street lights.
> .



But what would be the point? 200lumen at 1A is MUCH MUCH MUCH worse than sodium, to you completely use the main advantage.
The second advantage (color) is also your main disadvantage (color.... er... rendering).


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## uk_caver (Sep 16, 2010)

Are there figures for useful lumen output per Watt (or area adequately illuminated per watt) for various complete LED Units and sodium units?


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## MichaelW (Sep 16, 2010)

I don't know a Vf of a hypothetical 'big' PC amber Rebel, I would guess 3.0 as a bottom (a 10% improvement). It may be possible to drive this hypothetical 'big' PC amber to 1.5 amps, producing 250 lumens. But efficiency really suffers.

The spectral half-width of the phosphor converter amber is 80 nanometers [565-645, I think], way better than direct amber [20 nanometers, 580-600] LEDS, and infinitely better than LPS.

Efficiency is lower than LPS, but if LPS is completely unacceptable in the marketplace, that efficiency advantage is moot.


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## hank (Sep 22, 2010)

> Pros: very little light shorter than 530 nanometres-Helps with melatonin

Good to see this getting attention. I'd been wondering how wide the spread of the phosphor type amber LEDs would be.

I'd like to get one somewhere and send it to Craig at LEDMuseum to put on his spectrometer and get an honest output measured. I went looking for "low-blue" lamps sending him samples a few years back and all the "white" phosphor lights he checked for me have a big spike emission right in the band that suppresses melatonin. That's why I went with "turtle safe" amber for home evenings.


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## HarryN (Sep 23, 2010)

hank said:


> > Pros: very little light shorter than 530 nanometres-Helps with melatonin
> 
> Good to see this getting attention. I'd been wondering how wide the spread of the phosphor type amber LEDs would be.
> 
> I'd like to get one somewhere and send it to Craig at LEDMuseum to put on his spectrometer and get an honest output measured. I went looking for "low-blue" lamps sending him samples a few years back and all the "white" phosphor lights he checked for me have a big spike emission right in the band that suppresses melatonin. That's why I went with "turtle safe" amber for home evenings.



You don't need to go far to buy them, just put your order in at Future like everyone else and they come in the mail. Have you had a look at the data sheet for this part ? This is a tier 1 company we are talking about here that actually gets called to the carpet over what they put into data sheets, not some small time player.


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## hank (Sep 24, 2010)

> order in at Future
Good idea. Sure enough, I'd seen the main page but missed the R-and-D link for quantity 1 down at the bottom:
http://www.futureelectronics.com/en...ters/colour/Pages/7191828-LXM2-PL01-0000.aspx

You're right, fig.4 of the Data Sheet shows very low emission in 450-500, quick rise to the amber peak at 600, long tail up to 800. The tiny bump at 450 would be from the emitter underneath that activates the phosphor. That's very good absorbtion, assuming it's zero below 450.


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## jtr1962 (Sep 24, 2010)

*Re: Any thoughts?*



MichaelW said:


> How much you got...
> I like low pressure sodium,[efficiency & color] but dislike the highly monochromatic output. [who doesn't]
> I am thinking 200 lumens @ 1 amp drive, perfect in large groups for street lights.
> Pros: very little light shorter than 530 nanometres-Helps with melatonin, and I think bugs too.
> ...


And the point of using these over white is?

White is more efficient, renders colors better, has higher apparent brightness for any given lux, and finally doesn't kill peripheral vision like LPS or HPS or PC amber LEDs do. It's really the last thing which is a nail in the coffin for having low-CCT streetlighting. The melatonin thing is a distraction. Outside of the homeless, nobody sleeps in the street, so no need to worry about lighting interfering with melotonin cycles. If anything, LED streetlighting will be better at reducing light trespass into homes than discharge lamps. We've lived with HPS since the mid 1970s. Frankly, they stink. I get tunnel vision cycling on the streets, and the light color puts me to sleep. Asthetically, it's horrible IMO as well, basically clashing with moonlight and starlight.


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## LedTed (Sep 24, 2010)

I'd be curious to see two or three of these mounted vertically to "make up" a LED lamp.

With the Lambertian pattern from each LED, I think this could work quite well. 

Remember, you read it here first.


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## saabluster (Sep 24, 2010)

LedTed said:


> I'd be curious to see two or three of these mounted vertically to "make up" a LED lamp.
> 
> With the Lambertian pattern from each LED, I think this could work quite well.
> 
> Remember, you read it here first.


Hate to break it to you but you are far from the first person to think of this. Some have actually made real life examples as well.


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## hank (Sep 24, 2010)

>melatonin

Light doesn't work as an on/off switch. There's a countdown timer reset by daylight/blue light. The science is pretty new; last 20 years basically.
http://scholar.google.com/scholar?q=melatonin+light+receptor

Before electric light, after sunset, it took about three hours for melatonin levels to rise to where babies and older people to get sleepy. 

Young adults to middle aged have robust sleep cycles and notice less effect on sleep. 

Interrupting melatonin cycles also affects, for example, breast cancer rates:
http://jech.bmj.com/content/early/2010/07/14/jech.2009.101691.extract
Check the 'related' articles listed: 
http://www.springerlink.com/content/7v48464582n86113/

The other side of the issue -- you feel more awake, more alert, more lively with exposure to light that shuts off melatonin, and the effect lasts for several hours. It's the cheapest wake-up drug available, feels good.

Timing is all.

EDIT: here's a better summary on the biology: 
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2831986/
Environ Health Perspect. 2010 January; 118(1): A22–A27.
What’s in a Color? The Unique Human Health Effects of Blue Light
It references
http://ehp03.niehs.nih.gov/article/fetchArticle.action?articleURI=info:doi/10.1289/ehp.117-a20

I like the amber LEDs a lot, because they work real well at night without interrupting sleep; if I need to get up for some reason, but use only these lights, I can go right back to sleep, even at my advanced age. Mothers with young babies report comparable results with nighttime waking. Good tool.


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## jtr1962 (Sep 24, 2010)

hank,

That's all good and well to use amber in your home if you want to for the reasons you say. I'm talking about streetlight use where it's definitely detrimental to peripheral vision, as well as just plain ugly. While cycling at night I can't say how many potholes I just plain don't see until I'm almost on top of them because my peripheral vision is shot. The few places which switched to metal halide it was as if a veil of gauze was lifted. And you can use lower levels of high CCT lighting to achieve the same apparent brightness, resulting in less light trespass, less skyglow, and energy savings.

I find getting enough exercise is more than adequate to make me tired enough to sleep, even if I go to bed at 6 AM with sunlight streaming in.


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## hank (Sep 25, 2010)

Metal halide for your bicycle light:
http://www.sheldonbrown.com/marty_light_hist.html

Cities will go to LEDs; all the other lamps for streetlights have problems LEDs will be able to solve. http://www.eskimo.com/~jrterry/lampspage.html

Good news is the "current droop" problem with LEDs is being figured out.

Each time something like these new Rebels comes out they get more attractive.

LEDs eventually will likely be combined in several frequencies -- nobody likes monochrome illumination! -- while omitting the narrow bands associated with health and light pollution issues. It will be a big market, to have a win-win-win combination that does right by everyone involved. 
http://www.medical-hypotheses.com/article/S0306-9877(09)00166-2/abstract

I thihk the manufacturers will eventually produce the right combination with careful phosphor choice. Meanwhile I'll be trying to approximate it by combining monochrome LEDs -- again these new Rebels are promising for that.


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## jtr1962 (Sep 25, 2010)

Well, I agree we should make an effort to cut out that big blue spike at ~460 nm. We could still have excellent color without it.

I've wanted to get my hands on one of those PC ambers myself just out of curiosity. Maybe next time I order from Future. My guess is the spectrum would resemble HPS whereas typical amber LED is closer to LPS ( although not quite that monochromatic ). PC amber would be much better for your uses in that you'll still avoid short wavelengths but get somewhat better color rendering than amber.

hank, have you ever considered combining amber with red and possibly green? That might still prevent melatonin suppresson while giving pretty decent color rendering. Another possibility is a selective filter on regular whites which just cuts off everything below about 500 nm.


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## hank (Sep 25, 2010)

> combining
Yep, I've just been thinking of exactly that --one of Nailbender's 2-emitter dropins (Rebels won't fit but Crees would. Got to check spectra on Crees.

Rebels green emits from around 450, so it'd be iffy unless I added a Rosco filter like one of these, but for a flashlight, that loses a lot of brightness (I've used several like the two below on the monitor and other 'white' lights at home, evenings, where even a dimmed screen is pretty bright -- and on little 1xAAA white LED lights where I want dim yellow result.

http://www.rosco.com/includes/filte...mageName=../../images/filters/roscolux/15.jpg 
http://www.rosco.com/includes/filte...mageName=../../images/filters/roscolux/22.jpg

(click on the squiggle icons at this page to see other emission curves:
http://www.rosco.com/us/filters/roscolux.cfm#colors -- some are a good reminder that warm color temperature may still contain a whole lot of blue-green )

Aside -- older folks often need help with daytime wakefulness/alertness (many of whom don't get outdoors at all) and find bright light with a blue peak during the day helps; timing matters a lot: http://cme.medscape.com/viewarticle/528725_4
(Oops, edited, you need free membership at Medscape to see that; a brief quote for those who don't bother follows)

"As people age, the sleep/wake circadian rhythm becomes less synchronized, no longer producing the same response to external cues, and is much weaker and less robust, resulting in less consistent sleep/wake periods across the 24-hour day. The sleep/wake cycle in the older adult also shifts, or advances, comprising a condition called advanced sleep-phase (ASP). Older adults with ASP become sleepy in the early evening (perhaps 7:00 pm or 8:00 pm) and wake up in the early morning hours (3:00-5:00 am). This results in complaints of waking in the middle of the night and being unable to return to sleep.

"One problem that older adults with ASP encounter is not spending enough time in bed. Although tiring early, the older adult tries to stay up later in the evening but still wakes up early in the morning, which results in not getting sufficient sleep due to a short time in bed. In a second scenario, the older adult falls asleep in front of the television in the early evening, and then, once in bed, has difficulty falling asleep and staying asleep....."

___
I used to read in bed under a little 7-watt CFL and complain about having trouble falling asleep and staying asleep -- then we switched to amber LED evening reading light. Insomnia was gone immediately; we'd read 2-3 hours and get sleepy, like clockwork. My wife _hated_ the monochrome color -- but noticed the improved sleep right away. That's personal experience with the time delay involved, it really does take 2-3 hours after the last exposure to white light.

Of course sleep debt is a whole other story -- it does take some _months_ for the average adult to get "enough" sleep given the opportunity to really sleep soundly without any interruptions from light or other things. I recall being able to fall asleep any time, anywhere, when I was younger -- I thought it was an accomplishment. I probably was just running a month or two deficient of sleep for most of my adult life.

Anyhow enough digression, tho' I do hope to see more flashlights -- and fixed lights -- using these new Rebels for all the above reasons.

And emitters, emitters to fill in the 'hole' so there's more choices than just amber in between green and orange-red would really help with color rendering. I know from hearing about it (!) that people who knit and sew do care about color rendering.


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## ledpwr (Sep 26, 2010)

jtr1962 said:


> I've wanted to get my hands on one of those PC ambers myself just out of curiosity. Maybe next time I order from Future. My guess is the spectrum would resemble HPS whereas typical amber LED is closer to LPS ( although not quite that monochromatic ). PC amber would be much better for your uses in that you'll still avoid short wavelengths but get somewhat better color rendering than amber.
> 
> hank, have you ever considered combining amber with red and possibly green? That might still prevent melatonin suppresson while giving pretty decent color rendering. Another possibility is a selective filter on regular whites which just cuts off everything below about 500 nm.



After sitting in my room lit only by pc ambers, the light seems to be similar to hps as you expected, just more orangey. You can still easily make out other colours because of tiny amount of blue left in the light.
Adding red and green does increase the cri and creates yellow light. This really helps with plants and greens.

I recon the best combination is only green and pc amber as it would be efficient and removing reds doesnt change the cri much as the amber allready has a little red in it.


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## MichaelW (Sep 26, 2010)

*Re: Any thoughts?*



jtr1962 said:


> And the point of using these over white is?


When you are bicycling, you bring/make your own light. If you happen to hit a pothole, your suspension will take car of that.
Since Lumileds & Cree are more/less partners the PC amber could be applied to the xm-l package, 500 lumens per emitter.

http://www1.eere.energy.gov/buildings/ssl/m/outdoor_color.html
LEDs have no where to go, but up
http://www.lamptech.co.uk/Documents/IN Introduction.htm


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## HarryN (Sep 27, 2010)

*Re: Any thoughts?*



MichaelW said:


> Since Lumileds & Cree are more/less partners the PC amber could be applied to the xm-l package, 500 lumens per emitter.
> 
> QUOTE]
> 
> I understand your point, but I am not so sure that they view life this way. This is sort of like calling Ford and Toyota partners because they both make cars and probably have patent cross licences.


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## MichaelW (Sep 28, 2010)

Maybe view it as the GM/Ford partnership on transmissions.
GM: 6t70/75, Ford: 6f50/55
GM: 6t40/45, Ford: 6f35

Anyway the 'big' Rebel PC amber is hypothetical, so why not a further extension?

Competition benefits the consumer, and sometimes cooperation too.


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## SemiMan (Sep 29, 2010)

hank said:


> >
> 
> ___
> I used to read in bed under a little 7-watt CFL and complain about having trouble falling asleep and staying asleep -- then we switched to amber LED evening reading light. Insomnia was gone immediately; we'd read 2-3 hours and get sleepy, like clockwork. My wife _hated_ the monochrome color -- but noticed the improved sleep right away. That's personal experience with the time delay involved, it really does take 2-3 hours after the last exposure to white light.



This may work for falling asleep, but it is bad for your eyes. Your eyes need the shorter wavelengths in order to properly adjust the iris. Without those wavelengths, your iris is too wide wrecking your depth of focus and making your eyes strain and/or making the characters fuzzy. I wonder if you are finding your eyes are fatigued quicker?

I am really looking forward to LED streetlights .. or even induction flourescent, etc. Something about drivers being more awake and alert is certainly something I want when I am on the road.


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## Marcturus (Sep 30, 2010)

SemiMan said:


> This may work for falling asleep, but it is bad for your eyes. Your eyes need the shorter wavelengths in order to properly adjust the iris. Without those wavelengths, your iris is too wide wrecking your depth of focus and making your eyes strain and/or making the characters fuzzy. I wonder if you are finding your eyes are fatigued quicker?


Again, he's not trying to increase performance in a 500 lux classroom, not working through an entire textbook, not navigating a submarine for hours, but just trying to stay or become sleepy. I would hesitate to issue medical warnings without sound scientific backing. After all, mankind has evolved next to fire and candles. As long as the print wasn't red, I (myopic, non-colorblind) have never had any problem reading a bit with whatever red-orange lamp I happened to have available at night.


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## hank (Sep 30, 2010)

I'm no expert, just poking around, but there's some interesting stuff there.

I didn't know about the observation that hue as well as brightness controls pupil diameter -- found it, thanks. Here it is by the way:
http://www.google.com/search?q=blue+light+pupils+compared+luminance

We haven't noticed any problem, but I can think of several reasons:

-- we're using quite bright amber light
-- we have some outdoor light as well, in an urban area,
-- older eyes
----- poor "accommodation" (lenses are stiffer and slower to change focus)
----- maximum pupil diameter ("eye relief") gets smaller with age, and
----- reading glasses already give low depth of field. 

We haven't noticed any problems. And I haven't heard of this from astronomers, darkroom workers, or submarine or aircraft crews, and they use or used to use much dimmer pure red light, which I'd think would make focusing harder. But, til recently, that's been incandescent. Maybe with red LEDs they'd notice it? But with fixed brightness the pupils don't have to respond much at all. Hmmmm.

We don't get oddly wide pupils under the amber light, practically speaking, and the light intensity isn't varying so the pupils aren't working hard. So somehow we're not in the range described for that effect. 

Maybe the place to look for the effect would be an outdoor dark site with a monochrome source like low pressure sodium or a laser -- but without any other source.

One cat does get very wide pupils at night -- but she's spooky, likely she's just being 'interested' in every noise or breeze or smell.

In, heh, contrast, there's this: slightly better contrast perception with yellow:

http://onlinelibrary.wiley.com/doi/10.1046/j.1475-1313.1996.94000093.x/abstract
"The slight enhancement in yellow light was independent of letter size, and could not be explained by luminance differences between yellow and white displays. This effect may relate to the subjective improvement often reported when wearing yellow (blue-blocking) lenses."

I find there's a reason we can see some colors using only amber LEDs -- maybe a good enough reason not to bother trying to combine extra green or red? Dunno:

LEDs aren't really monochrome sources, the emission curve is fairly broad, as pictured in the Rebel doc illustrations. The amber LED output overlaps the sensitivity of two of the three color receptors, "M" and "L" in this picture:
http://upload.wikimedia.org/wikiped...87px-Cone-fundamentals-with-srgb-spectrum.png

Receptors shown there combine for color vision -- and people apparently vary quite a bit even with full color vision, or at least the molecules/genes, vary a good bit
http://www.sciencemag.org/cgi/content/abstract/sci;232/4747/193
(This is old but many later papers cite it): "red and green pigments show 96 percent mutual identity but only 43 percent identity with the blue pigment. Green pigment genes vary in number among color-normal individuals ... a single red pigment gene"

The color vision genes are on the X chromosome, so some women, who can have slightly different genes on each of their two X chromosomes, get more color receptors and more precise color vision. And men are more likely to be color-blind because they get (or miss) the genes only from their single X chromosome: 
http://pbr.psychonomic-journals.org/content/8/2/244.abstract

Ain't science wonderful? 

-------

It's good fortune that the amber LED emission falls so nicely in the overlap between two visual pigments which also overlap. 

I wonder whether tunable LEDs or phosphor LEDs could be produced that emit everything except the melatonin-controlling range, or filters made that remove only that narrow band without losing much brightness like the color filters for photography.


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## SemiMan (Oct 1, 2010)

Marcturus said:


> Again, he's not trying to increase performance in a 500 lux classroom, not working through an entire textbook, not navigating a submarine for hours, but just trying to stay or become sleepy. I would hesitate to issue medical warnings without sound scientific backing. After all, mankind has evolved next to fire and candles. As long as the print wasn't red, I (myopic, non-colorblind) have never had any problem reading a bit with whatever red-orange lamp I happened to have available at night.



Hello! ... Sound scientific backing? ... When did physics stop becoming sounds science? If you do not understand the simple concept of depth of focus ......

Mankind evolved with sunlight and moonlight. Candles and fires are a recent phenomenon with text a very recent discovery. In order for "evolution" to occur, there would need to be evolutionary pressure based on improved survivability w.r.t. vision near a fire or candle. I am thinking that would be minimal if any in the limited history.

That said, it's your eyes.... but you may just want to try reading with the same level (lux) either photopic or mesopic referenced of red-orange light and cool white LED light. The text will be crisper with the cool white LED. Yes I can read with dim red (or yellow) biased light. That does not mean that I should.

"I wonder whether tunable LEDs or phosphor LEDs could be produced that emit everything except the melatonin-controlling range, or filters made that remove only that narrow band without losing much brightness like the color filters for photography." Unfortunately it is not a narrow band. It is everything from virtually 400 - 525nm. It peaks at 420nm, but it is still at 40% of its peak at 515nm. If you start with the 2700K Luxeon Rebel (LXM8-PW27), then you could probably lop off the spectrum below 550 without losing much overall brightness.


Semiman


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## hank (Oct 1, 2010)

Seems to me making pointy rocks and leakproof baskets by firelight has gone on quite a while, http://www.google.com/search?q=first+use+of+fire
Hmmm. Sitting up working by firelight versus spending all night under the bearskins? Being farsighted and half blind by firelight might be well favored by evolution!

Yes, dim red doesn't focus well, especially for closeup work. Workaround: shine the LED into one eye, making the pupil contract, improving focus briefly -- for example, to set the dials on a padlock. I did that for years til I discovered yellow LED keyfobs -- no problem with those. And not long after, I discovered CPF and got brighter. Er, lights.

No question, focus might be a problem for someone. Haven't noticed it myself.


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## jtr1962 (Oct 1, 2010)

The focus issue may depend upon whether you're farsighted or nearsighted. If you're nearsighted, like me, then by my experience you need blue light in order to prevent visual fatigue and also to see well. Based on some of your posts I made a light with 4 amber luxeons a couple of years ago. Honestly, despite my best efforts, I could never get comfortable under this light. It wasn't just the low CRI, either. Everything just seemed fuzzy. Sure, it might be fine for getting up late nights to use the bathroom, but for me it had little utility for any kind of task requiring visual acuity. And incidentally I have the same issues under LPS/HPS, candlelight, and even household incandescent ( although 3300K-3400K overdriven incandescent is tolerable to me for detailed tasks ). For a farsighted person, the opposite may well be true.

Incidentally, so far my need for blue light when doing any detailed tasks hasn't impacted my sleep cycles. Once I get reall tired, nothing seems to stimulate me, even intense blue light. I've fallen asleep in front of my monitor more times than I care to think about.


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## Marcturus (Oct 1, 2010)

SemiMan said:


> When did physics stop becoming sounds science?


technical acoustics is still part of physics, that's correct


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## HarryN (Oct 1, 2010)

It would be nice to get back to this being a Rebel LED thread.


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## Black Rose (Oct 2, 2010)

HarryN said:


> It would be nice to get back to this being a Rebel LED thread.


+ 1


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## hank (Oct 4, 2010)

The digression helped me understand why I can see colors using only amber LEDs, and to spec and order an amber-LED P60 dropin from Nailbender. Thanks for your patience.

Thanks also for the pointer to spectral power distribution at
http://www1.eere.energy.gov/buildings/ssl/m/outdoor_color.html; very helpful to compare to the info in the Rebel docs.

Here's a Rebel ES: ("Energy Saving")
www.philipslumileds.com/uploads/17/DS61-pdf


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## blasterman (Oct 4, 2010)

I've gone through several brands of amber LEDs, and the analogy to HPS is vague at best. Most modern HPS lights have added materials in the jacket to yield additional spectral spikes to improve low lux driving. 'Is it pink or is it yellow'? Actually...both.

Amber LEDs I've worked with are far more monochrome in nature than HPS. They act quite a bit more like LPS and are close in color. I've tried building effect and ambience lights with amber LEDs and it has the same issues as LPS; Objects lack dimension, colos are deceptive, and it just doesn't work well....except maybe in a photographic darkroom. I've since delegated ambers to adding some warmth to neutrals or warm LEDs.

Just a suggestion, but melatonin is readily available as a suppliment and is pretty cheap. Never found it to help with sleeping, but the vivid dreams it produces are fun.


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## hank (Oct 4, 2010)

Rebel ES -- currently available in "cool white" and "neutral white" 
(July 2010)

@ 350 mA Forward Current 125/130 lm (that's neutral/cool, at 25°C)
@ 700 mA Forward Current 220/225 lm
@ 1000 mA Forward Current 300/310 lm

"... Rebel ES products with even higher luminous flux levels will become available"

" tested and binned at 700 mA, with current pulse duration of 20 ms.... with current pulse duration of 20 ms. ... junction temperature and thermal pad temperature are the same."

But -- 25C -- is 77 F. So the Rebel ES (and other) specs are for LEDs kept _very_ well cooled. How hot do flashlights go with these Rebels, anyone know?


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## Curt R (Oct 4, 2010)

There are two brands of testing machines, one test is done at 20 ms and the other one does the testing at 25 ms. 
All testing is done at a controlled temp of 25 C before the LED has a chance to heat up because there is no way 
to heat-sink the LED under test. That testing procedure determines the voltage drop, output and tint of the LED. 
All done in the blink of the eye. At the rate of over 10's of thousands per hour.

Curt


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## EntropyQ3 (Oct 5, 2010)

Curt R said:


> There are two brands of testing machines, one test is done at 20 ms and the other one does the testing at 25 ms.
> All testing is done at a controlled temp of 25 C before the LED has a chance to heat up because there is no way
> to heat-sink the LED under test. That testing procedure determines the voltage drop, output and tint of the LED.
> All done in the blink of the eye. At the rate of over 10's of thousands per hour.
> ...


Is this done per batch or wafer, or is it done per actual LED chip?


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## saabluster (Oct 5, 2010)

EntropyQ3 said:


> Is this done per batch or wafer, or is it done per actual LED chip?


per chip.


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## registable (Mar 27, 2014)

*Re: All hail the big Rebel!*



MichaelW said:


> How else exactly would they increase the maximum drive current to 1.5 A without an increase in die size.
> The thermal pad looks unchanged. The thermal resistance is less, 6 vs. 10.
> and the 'dot grid' is 5x5 instead of 4x4
> 
> ...



I am quite new in these LED field. But I always saw these 'dot grid' on flip chip LED, at first i thought is bump contact but for luxeon rebel ES the middle line of dots are not on the cathode or anode. So what is it exactly?? If Rebel wants to increase the surface emitting area, why not use back the 4x4 dot grid with larger chip?


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