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Thread: Preview of updated K2: testing of "new" K2 sample

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    Default Preview of updated K2: testing of "new" K2 sample

    PhotonFanatic was kind enough to send me a sample of a 'new' version of the K2. The part number is LXK2-PWC4-0160. Using the K2 part number decoder ring tells me that this should be a 160 lumen at 1A part. Notice the lack of an alphabetical bin marker - it looks like Lumileds is moving to the Rebel part numbering system for K2s. It's likely they will also move to the rebel binning structure for Vf and Luminous flux as well.

    These parts don't seem to be available anywhere yet, nor are they listed anywhere either. Given the recent release of higher brightness Rebel parts, using the thin film die and new phosphor, it's reasonable to assume that this new version of the K2 is also using the same construction for the die/phosphor.

    First up, a visual comparison between the existing K2 (PW12-S00) on the left, and the 'new' K2 on the right:

    Head on (apply directly to the forehead!):


    You can see that the new K2 has a different phosphor, since you can see the dot pattern of the die through the phosphor now, much like the difference between the 100 lumen rebel and the older rebel. In addition, the silicon submount is a gold color - however, I think I've seen K2s with gold colored silicon submounts before, so I'm not certian that it's an entirely new feature.

    And from the side:


    The die/phosphor combo is shorter, again like the difference between the new and old rebel. This should make the beam project relatively more forward (less side emitted light) compared to the old K2. So it looks like indeed, the new K2 is using the thin film technology, which eliminates the sapphire substrate part of the die.

    Let's check out the beam profile:


    The new K2's beam profile is a little different, projecting less out the side as predicted. This might affect the beam slightly when used with reflectors.


    Here is the raw performance data for the new K2:

    Code:
    Current (mA)		0.1	30	130	310	670	980	1260	1570	1930
    ---------------------------------------------------------------------------------------------
    Vf			2.53	2.75	3.05	3.25	3.47	3.60	3.68	3.78	3.89
    
    Watts					0.40	1.01	2.32	3.53	4.64	5.93	7.51
    
    Lumens					33	75	141	187	221	257	292
    
    Lumens/W				84	74	61	53	48	43	39
    This part is supposed to be 160-180? lumens at 1A. It looks like this part is performing at the high end of the bin range.



    Compared to other power LEDs in the same class:

    First, Vf:


    The Vf of this sample is higher than most of the others. This will cause it to take a hit in the efficiency department.


    Next, output:


    This sample is performing about equal to the Cree XR-E P4 bin. Hopefully better performing versions of the new K2 will be available when the update to this part is announced. It would seem rather silly that the Rebel would out-perform the K2 - Lumileds can produce very high performing LEDs in the rebel line - there doesn't seem like much reason to keep those improvements from getting into other products immediately.

    Efficiency:


    Even though this sample about equals the XR-E in output, it lags in efficiency, due to the higher Vf.



    Finally, "droopyness"


    If the rebel didn't have "anti-droop" technology, then the new version of the K2 also doesn't. The new K2 scales pretty much the same as all the other parts.

    While this was just a sample part, it's nice to see Lumileds finally get their buts in gear and get the K2 performing in the range of the Cree and Seoul parts. This sample definitely wasn't a performance leader - hopefully the final release parts perform better. Lumileds is going to have to stay on the ball with this if they are going to keep up with the pace that Cree has set in the last year for performance increases.

    Of course, we'll have to see how long it is before Lumileds decides to make these new K2 parts available for everyone.

    The time frame, performance, and pricing of these new K2 parts will all effect how willing people are to use them. If we have to wait to long to get the improved parts, people will begin to fear "another K2", where parts were promised but never delivered. The new K2s will have to perform much better than this sample for people to decide to use them vs. the higher performing Cree parts (Q4, Q5, and better).
    Last edited by evan9162; 08-05-2007 at 02:49 PM.

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Hi,
    Where have you bought the "new" K2 LEDs?
    Opto-King

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Thanks for the info!

    -N
    My mods. Please post questions about my mods to the corresponding thread: like that all CPFers can get the info - thanks!

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    yeah ,,,thanks for that info,,,will the led wars be heating up again ?
    my lights -Fenix L2D20,Surefire E2L outdoorsman ..

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    Flashaholic* Manzerick's Avatar
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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Wow.. Looks promising!!



    I hope I get the job in the LED division of Phillips!!!

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Quote Originally Posted by Opto-King View Post
    Hi,
    Where have you bought the "new" K2 LEDs?
    I didn't. I was sent a sample that someone else received. These are not available for sale yet. There are no announcments, nor timelines for any new release known. The only thing we do know is that there is supposed to be a Q3 (July->September) release from Lumileds. The updated Rebel released in july. It's possible that that's the Q3 release that was mentioned, and if so, it could be a while before we get these.

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    Flashaholic* Nereus's Avatar
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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Evan, which luminous bin is the Seoul P4 you are using as a benchmark?

    -N
    My mods. Please post questions about my mods to the corresponding thread: like that all CPFers can get the info - thanks!

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Thanks for the info, will be interessting to see when it "comes out" and how it will look when released.
    Opto-King

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Thanks for testing and posting the info.
    I suspect that there are more than a few of us that did not want to re work perfectly good reflectors and are patiently waiting for a 'higher performing '
    Lux III ( Gen X ) with its excellent heat sinking , overall build quality and oh so nice and smooth beam.

    Lets hope this re launch of the K2 goes better than the first.
    David............................................. "A few of my Home Built lights"

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Quote Originally Posted by Nereus View Post
    Evan, which luminous bin is the Seoul P4 you are using as a benchmark?

    -N
    U-bin.

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Lumileds just released a press release today announcing "Lumiramic" phosphor technology, that's supposed to give better performance and much tighter/more control over color bins.

    http://www.luxeon.com/newsandevents/releases/PR77.PDF

    Here are the more interesting parts that are relevant to this thread:

    Lumiramic phosphor technology utilizes a ceramic phosphor plate and the company’s new Thin Film Flip Ceramic substrateCeramic substrate. TFFC technology, recently introduced in Luxeon Rebel, is the only thin film process that removes the anode and cathode from the light output path and provides an unobstructed plane to which the Lumiramic plate can be applied.
    So we know the rebel isn't using Lumiramic

    Lumiramic and TFFC were two of the key technologies used to achieve the 115 lm/W performance announced earlier this year
    Philips Lumileds will introduce Luxeon products with Lumiramic phosphor technology in early 2008 and will begin sampling programs with customers in the lighting community in the fourth quarter of 2007.
    So it looks like we won't be getting the 115lm/W parts until 2008, at least not by means of this new phosphor. If we do get 115lm/W from lumileds, it'll be using what the rebel/new K2 are currently using.

    Who knows what this means for when the "new" K2s get released either.

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    evan9162 Comparatively if we see the currently available Q5 Crees, they are around 115 Lumens / Watt already aren't they?

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    The 115lm/W LED that Lumileds mentioned produced 135 lumens at 350mA.

    The Cree Q5 bin is 107-114 lumens at 350mA. They specify a typical Vf of 3.3V at 350mA, which makes the efficacy of the Q5 bin range from 93 to 98 lm/W. Of course, individual samples may have a lower Vf than the typical value, so of course, the efficacy will be higher. But the most you could expect from a Q5 cree would still "only" be 105lm/W.

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    ...great job, evan, thank ya for your testdrive and the macropics!

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    Sigh Re: Preview of updated K2: testing of "new" K2 sample

    i was begining to lose hope that lumileds would put a rebel die into a k2!

    oh well just 30 bucks on those 0100 rebels

    went down that k2 road

    no drivers

    no batts to supply 1500 ma for a reasonable time

    what was the k2 for anyway?

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    - The K2 is reflow solderable, wheras none of the other luxeons were
    - The K2 package is designed to deliver better thermal performance than previous luxeon packages (9C/W case-> junction vs. 13 C/W)
    The package and die were designed to allow 1500mA of current safely
    The package and die were designed to allow for high junction temperatures (185C in green and blue vs 135C before). This allows reduced heat sinking and for the device to be run in a much harsher (hotter) environment than previous luxeons.
    The package and die were redesigned to deliver high lifespan at high temperatures and currents. A luxeon III driven at 1A will degrade to 50% output after 20,000 hours. A K2 driven at 1.5A will degrade to 70% after 60,000 hours. For this lifespan, the Luxeon III junction temperature had to be maintained at 90C or below. The K2 junction temp only needs to be maintained at 120C or below.

    So the K2 introduced a high current package and die, with better thermal performance, that's reflow solderable, that allows the device to be run at hotter temperatures with less heat sinking, and maintain output longer than previous devices.

    Most of these improvments are not targeted at the modder that will use one or two. A lot of these improvements have to do with making the K2 more compatible with industry standard manufacturing processes, and making the K2 more compatible with existing form factors by requiring less heatsinking for the same power dissipation.

    I would hold onto your rebel-100s. We still have no idea when the improved K2s will release. Lumileds is notorious for dragging their buts on releases relative to smaller LED companies. Though that may be purely for business reasons. Only they really know for sure.

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    wow 3.6V near 1A current.. now, that is good news
    if killing was legal, i would have killed countless number of people...

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    So the K2 which is due to be released soon performs about as well as the Cree which was released a year ago?

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    evan9162 - wow and thanks for the superb report! I know a lot of time and effort went into it, and I for one owe you my gratitude for the technical details. Great summary post this morning, too. I am guessing you are a technical writer by trade... or could be.

    I have used some K2 LEDs in the portable lamps I have built to use with my digital camera. The tint and smooth dispersion pattern of the luxeon line has impressed me - especially compared with Cree and others.

    chris_m, you need to stare harder at the Lumious Flux chart above!

    Happy Equinox (almost) ya'll!

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Quote Originally Posted by chris_m View Post
    So the K2 which is due to be released soon performs about as well as the Cree which was released a year ago?
    There are -160, -180, -200, and -240 parts in the PWC4 part number. The 200 should perform around the same as a Q3 Cree or Rebel 90. The -240 Will perform about what a Rebel-100 or Q4 will. There's also a PWC2-110 part that will deliver 110 lumens at 350mA.

    The different output levels will fit into different pricing segments. As a product line, it seems that it will be reasonable competitive.

    I seems that you're bound and determined to lay on the hatorade on these products. If you're going to do that, please don't clutter up this thread with meaningless sniping comments.

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    I just think there needs a little perspective to the "love-in" which seems to happen on here with every Luxeon pre-release announcement. I sometimes wonder whether if Luxeon released a part which was miles behind the current state of the art efficiency but still a little better than what they had released before there would still be people on here swooning over it because it was a drop in replacement for lights they bought back when Luxeon USED to be the performance leader.

    I'll give you that certainly the Rebel is a good performing part, but there is as yet no evidence that we will see K2s released in the near future which even do as well as that. Meanwhile some of my irritation is that your graphs seem to show that this K2 you have performs as well as a Cree and the Rebel better, and it does NEED to be pointed out that the Cree part in your graphs is a really old bin, so it's not really a very current comparison. Is all very well you commenting on the bins listed in Luxeon's bin structure - actually seeing such parts in the real world is another matter (noting that Cree has R4 bins in it's bin structure, which is 130lm at 350, so ~290 at 1A).

    jeff - I've looked again at that graph, and it still doesn't show the K2 on test performing any better than the Cree P4.

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    The difference between a P4 and a Q4 Cree isn't all that exciting IMHO. However, being able to use all the stuff (reflectors, optics, heads, bezels, drivers, ...) we were using back then with the Luxeons again with the K2 is worth a lot. There is experience, the wheel does not need to be re-invented as it had to be withthe Cree and Rebel.

    bernie
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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Quote Originally Posted by chris_m View Post
    I just think there needs a little perspective to the "love-in" which seems to happen on here with every Luxeon pre-release announcement.
    There's the same amount of "love-in" over Cree announcements and new XR-E bins that are released. CPF is an enthusiast site. People get excited over new releases, increased competition, and more choices. Sheesh. Why do you even visit this place if you don't understand that?

    I sometimes wonder whether if Luxeon released a part which was miles behind the current state of the art efficiency but still a little better than what they had released before there would still be people on here swooning over it because it was a drop in replacement for lights they bought back when Luxeon USED to be the performance leader.
    Luxeon is a part name. Lumileds is a LED manufacturer.

    Anyways, I very seriously doubt it. The V-bin K2s have been available in quantity for about 6 months now, and no one gives a crap because how far they are behind the curve in terms of efficiency. No one is swooning in this thread. The only thing that people are getting interested in is the fact that Lumileds just might get back into competition in terms of efficiency, where Cree and Seoul have been leading for a long time. I thought more choices were a good thing?

    I'll give you that certainly the Rebel is a good performing part, but there is as yet no evidence that we will see K2s released in the near future which even do as well as that.
    We have no idea when these are coming out. But since people have been getting samples, and the parts have even shown up temporarily on Future's parts listings, so it sounds like it could be soon. Lumileds is notorious for dragging their feet on new releases, a fact that universally annoys everyone.

    Meanwhile some of my irritation is that your graphs seem to show that this K2 you have performs as well as a Cree and the Rebel better, and it does NEED to be pointed out that the Cree part in your graphs is a really old bin, so it's not really a very current comparison.
    Well ex-fucking-cuse me for not owning all the latest and greatest LEDs on the planets that meet your standards for comparison. I didn't have anything but a P4 XR-E when I did this test. How am I supposed to include data for a part I don't have? Why not truck on over to my XR-E Q4 review to see it compared there?

    It's people like you and responses like this that discourage people from doing these kinds of investigations and sharing information, when the only thing that happens is that they get sniped at because someone doesn't like some insignificant detail about how things were done. It's definitely goes against the spirit of CPF when you behave like this.

    This was an opporotunistic test of an unreleased part. It's normally something people look forward to. People don't look forward to someone threadcrapping all over everything just because they feel like making snarky comments that lower the level of discourse.

    Is all very well you commenting on the bins listed in Luxeon's bin structure - actually seeing such parts in the real world is another matter (noting that Cree has R4 bins in it's bin structure, which is 130lm at 350, so ~290 at 1A).
    ARC Mania had -200 parts on hand a while ago. The current Rebel-100s hit the mid 230s at 1A. There's no reason that -200 parts shouldn't be in abundant supply whenever they get around to releasing these. Even -240 parts should be reasonable, again, given the current performance of Rebel-100 parts.

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    Flashaholic* Anglepoise's Avatar
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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Keep up the good work Evan. Much appreciated .
    David............................................. "A few of my Home Built lights"

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Quote Originally Posted by Anglepoise View Post
    Keep up the good work Evan. Much appreciated .
    +1
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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Quote Originally Posted by evan9162 View Post
    There's no reason that -200 parts shouldn't be in abundant supply whenever they get around to releasing these. Even -240 parts should be reasonable, again, given the current performance of Rebel-100 parts.
    One thing which concerns me isn't that Lumileds can't make a competitive LED. They obviously can with the recent Rebel 100s. Their biggest problem is production. Rebel 100s aren't currently available. They only were for perhaps a month, and even then I couldn't get an answer on buying a specific bin as with the Crees. There may indeed be a -240 K2 soon, but if it's only available for a short time, and not again for weeks or longer, then what good is it? At least when Cree releases a new bin, it'll be out there in large quantity, even if admittedly a little expensive/hard to get in the beginning. I really hope that the K2 -200s and -240s are available in large quantity soon, and at competitive prices. The more players in this ballgame, the better it'll be for everyone.

    And thanks for the great review!

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    Naughty Re: Preview of updated K2: testing of "new" K2 sample

    I am sure chris m would love to send evan a Q5 to update his tests

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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Quote Originally Posted by Anglepoise View Post
    Keep up the good work Evan. Much appreciated .
    What Anglepoise said

    I enjoy all your reviews.

    Thank you for the effort.
    Last edited by Grox; 09-24-2007 at 05:39 AM.

  29. #29
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    Default Re: Preview of updated K2: testing of "new" K2 sample

    Quote Originally Posted by jtr1962 View Post
    One thing which concerns me isn't that Lumileds can't make a competitive LED. They obviously can with the recent Rebel 100s. Their biggest problem is production. Rebel 100s aren't currently available. They only were for perhaps a month, and even then I couldn't get an answer on buying a specific bin as with the Crees. There may indeed be a -240 K2 soon, but if it's only available for a short time, and not again for weeks or longer, then what good is it? At least when Cree releases a new bin, it'll be out there in large quantity, even if admittedly a little expensive/hard to get in the beginning. I really hope that the K2 -200s and -240s are available in large quantity soon, and at competitive prices. The more players in this ballgame, the better it'll be for everyone.

    And thanks for the great review!
    Yes, I've noticed this too, and it's rather puzzling. Huge availability first, then none anywhere. Their production ability / supply chain is very wierd. Perhaps they're diverting their thin film die production to the new K2 ramp. Or perhaps they're just having problems, and can't produce fast enough. Who knows? From what we can see, Lumileds seems to lack production consistency (not in terms of product quality, but in terms of output volumes). Definitely not the kind of behavior you expect from a big player in the LED market.

    A lack of availability of parts definitely hurts them, and makes potential customers switch to another available option, even if it means re-working their design for a new package or beam profile.

  30. #30

    Default Re: Preview of updated K2: testing of "new" K2 sample

    dude a arms race with LEDs...

    anyways didnt know that rebels can go up to 1.8 amps...O.o

    where and how much did u get them for? i want to try.

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