K2’s are here!

Just received the shipment this evening.
The K2's are only R Bin, the U Bin's are still on backorder.

My "luck" from the Luxeon Lottery this time was some RW0L's

I will try and post some Pic's when I get a chance

Can't believe I am the first kid on the block to get their order:wow:

R binned 3 watts? Doesn't sound too good to me. I guess maybe they can stand to be overdriven to produce more lumens? Maybe I don't know enough yet, but the minimum I'd want are U bin, otherwise I don't see the point. Are you happy with R bins, and maybe there is still some advantage of them being K2 that I'm ignorant of?

p.s. I know that LuxIII's are not really 3 watts, wattage all depends how you drive them. It just seems that the L suffix is not even more efficient than a J bin. Maybe I'm misunderstanding or over emphasizing bin codes and numbers?

On behalf of MrTodds, thanks for the wet blanket.

Bernie

TorchMan said:

R binned 3 watts? Doesn't sound too good to me. I guess maybe they can stand to be overdriven to produce more lumens? Maybe I don't know enough yet, but the minimum I'd want are U bin, otherwise I don't see the point. Are you happy with R bins, and maybe there is still some advantage of them being K2 that I'm ignorant of?

p.s. I know that LuxIII's are not really 3 watts, wattage all depends how you drive them. It just seems that the L suffix is not even more efficient than a J bin. Maybe I'm misunderstanding or over emphasizing bin codes and numbers?

Click to expand...

Yes, RW0L is not that exciting. But at $3.50 they are good for experimenting with various K2 emitter mounting & reflector configurations.

What is exciting is this means they are shipping U or V Bin's, after all a R bin is a U bin that got a "D" on the final exam.

The U bin's are probably going to premier manufactures like SureFire first.

I am guessing the R-bins are part # LXK2-PW12-R00 ???

The lumileds site has 5 different part numbers:

LXK2-PW12-R00
LXK2-PW12-S00
LXK2-PW14-T00
LXK2-PW14-U00
LXK2-PW14-V00

Doesnt the letter at the end specify the bin for K2s? So if you got R-bins does this mean you ordered part number LXK2-PW12-R00?

Sawtooth said:

I am guessing the R-bins are part # LXK2-PW12-R00 ???

The lumileds site has 5 different part numbers:

LXK2-PW12-R00
LXK2-PW12-S00
LXK2-PW14-T00
LXK2-PW14-U00
LXK2-PW14-V00

Doesnt the letter at the end specify the bin for K2s? So if you got R-bins does this mean you ordered part number LXK2-PW12-R00?

Click to expand...

Yes you are correct. I ordered both LXK2-PW14-U00 and LXK2-PW12-R00 which were the only ones you could order back in January. The U's are still on backorder.

TorchMan said:

R binned 3 watts? Doesn't sound too good to me.

...

Maybe I'm misunderstanding or over emphasizing bin codes and numbers?

Click to expand...

Yes indeed, very much so.

The -12 parts (which this R bin is one), are binned at 350mA drive current (essentially 1W). So this K2 is as good or better (likely better) than a 1W R bin. Have you seen how much guaranteed 1W R bins are going for?

Plus, you can drive this K2 up to 1500mA.

Thank you evan9162 for that info. I wonder how many lumens they produce at 1500ma?

With a Vf bin of L at 350 mA, consider what the Vf will be at 1500 mA. :green: I would be inclined to compare these to rather inefficient T flux binned Luxeon III's with the ability to be driven harder but at a cost; without good thermal relief, there is likely little gain, if any. :shrug:

The 12-S and 14-V parts might be a marked improvement in efficacy if the Vf is not unreasonable. Otherwise, I think we will be seeing some less expensive LED's from Lumileds that may rate higher in lumens for applications and marketing where the whole story is left off the pages but bright sells the papers.

so tell me guys, what is a k2...why the big fuss...I am totaly ignorant on this topic...not tryin to hijack..just hoin someone can enlighten me real quick..thanks guys

K2s are lumileds newest offering. Two major pluses I see are:

(1) much lower cost per lumen.
(2) you can order known flux bins -- i.e. no crap shoot on the flux bin
like there is on the Lux III's and V's...

Right now U-bin Lux IIIs are very expensive ($30 each???). The new U-bin K2's are only $3.45 each! V-bins apparently arent available for ordering yet and I dont know what the prices will be on those. But I'm thrilled to be able to get U-binned emitters for under $5!

Could I just throw a K2 R bin in an original L1P and drive it with a CR123 and it would work?

Sawtooth,

Cost per lumen is relative to the whole package ultimately. A $3 difference is more significant in a $30 light than it is in a $200 light.

$30 for a U bin Lux III? Is that from Future or aftermarket? If someone gets their hands on some K2's that are S or V bin, do you think these will be resold for $3.45? :shrug: How many U bin emitters have you bought for under $5? Has anyone picked up PW14-U00 yet?

I have a reel of PW12-S00's on order but have not received notification of shipment yet.

In time, all of these LED's are all going to go up in flux and down in price but the cream of the crop will always bring a premium price at the edge where folks know and care about such things. :shrug:

I do follow your point but it is based on comparing vapor with reality and the two have different price structures, IMHO.

Re: K2's are here!

evan9162 said:

Yes indeed, very much so.

The -12 parts (which this R bin is one), are binned at 350mA drive current (essentially 1W). So this K2 is as good or better (likely better) than a 1W R bin. Have you seen how much guaranteed 1W R bins are going for?

Plus, you can drive this K2 up to 1500mA.

Click to expand...

Not really though:
3.87 Vf on average for that bin (note the L bin for Vf)
3.87V * 350mA (binning current)= 1.3545 watts
45 lumens (typical bin brightness) / 1.3545 Watts = 33.2 lumens per watt

and that is before temperature losses...


According to the datasheet, the R bin is only a 700mA part max? Or maybe that is binning, as later it says 1500mA absolute max. The lumens per watt drops even faster, going below 28 lm/W, before the additional losses caused by die heating.

Datasheet:
http://www.lumileds.com/pdfs/DS51.pdf

Binning sheet:
http://www.lumileds.com/pdfs/AB21.pdf

Re: K2's are here!

What's the vf for one of these bad boy's?

"The lumens per watt drops even faster, going below 28 lm/W, before the additional losses caused by die heating."

...and most of us use some kind of driver for the led. If it is 85% efficient, we are seeing ~20 lm/w total efficiency here (this includes thermal losses).

-Nereus

kinda curious why we aren't seeing these sold on stars- or is that planned for the furture... I'd really like to be able to drop a K2 into light that normally uses a star... I'm kinda waiting on doing an LED mod untill I see and hear more about the K2s... not to mention- other manufacture offerings.

sawtooth: the Ubin luxIII is rated at 700ma. The U-bin K2 is rated at 1000ma. Do the math and you'll see the U-bin K2 isn't that great compared to a U-bin LuxIII. The LuxIII Ubin would still be the best animal to get in this case.

A 400 Lumen K2 U-bin Quad-Lux sounds fun to me. As long as the Vf is fairly low, the heat would be very manageable at a 1 Amp drive. The price will be easier to swallow too.

MillerMods said:

A 400 Lumen K2 U-bin Quad-Lux sounds fun to me. As long as the Vf is fairly low, the heat would be very manageable at a 1 Amp drive. The price will be easier to swallow too.

Click to expand...

- bold added by me

But the problem is that it seems the Vf on these has jumped significantly!!! Even the colored K2's I tested had high Vf!

The K2's I have seen and hear about from others have two advantages over a T bin Lux III, a few dollars in price saving and the ability do be driven at higher current levels, within spec. If someone can demonstrate a K2 being superior to a Luxeon III T bin, at any drive level, I will back off and sit in the corner. I refer to demonstrating with a real LED and not with a theoretical one derived from the bin structure.

Two trite but possibly revealing statements: You get what you pay for. The K2 is cheaper than a Luxeon III.