# K2 and K2 TFFC Technical Information Thread



## HarryN (Feb 26, 2009)

Hi, I thought it might be nice to have a thread dedicated to technical information on the Philips Lumileds K2 and K2 TFFC package.

My goal in starting this thread is not make this a "K2 vs Others war" thread, just a place to post concentrated information the K2, how it works with various optics, reflectors, drivers, etc.

These devices are pretty time tested, so there are plenty of users and user experiences. This is an easy LED package for DIY hobby use, so even I can solder them up, and there are many optics options.

Just to start off with some basic information, here is a link to the main Philips Lumileds K2 page:

http://www.philipslumileds.com/products/luxeon/luxeonK2

What I didn't realize until today, which makes a concentrated thread like this valuable to me at least, is that the K2 TFFC is only available in cool white, while the "conventional" K2 package is available in cool, neutral, and warm white, along with various colors. Perhaps I am the only one that didn't know that. - (note - this is no longer the case, as edited below)


Also, for those interested, here is a link to their main distributor (Future) who is selling the K2 TFFC, 200 Lumen (rated) device for under $ 10 in qty 1 each, and less than 1/2 of that in reel qty.

http://www.futureelectronics.com/en...hifted|*LXK2/-PWC4/-0200*|1|,Ny:True,Nea:True

Thanks

Harry


____________________________________________________

Update 18 June 2009, per blindasabat:

a)


Blindasabat said:


> You ought to add to the first post that K2 TFFC Neutral 180L @1Amp is availble at Future.



b) Future now stocks cool white 220 lumens (but not 240) even though they are not listed at the Lumileds main site. http://www.futureelectronics.com/en...erSearch|lxk2/-pwc4/-0220|1|,Ny:True,Nea:True

c) Future is selling cool white 200 lumens K2 TFFC with two Vf bins (1000 ma test current)
http://www.futureelectronics.com/en...erSearch|lxk2/-pwc4/-0200|1|,Ny:True,Nea:True

d) There was a time in the past when Future would only sell in 1 reel quantity, and this frustrated some end users. Just so everyone knows, you can buy directly from Future in single unit qty, and I have done it. Of course, there is a limit to what you can buy in cut tape as far as binning, espectially for exact color and Vf.

e) CPF member and dealer Photon Fanatic (whom I have had excellent dealings) is selling some K2s and other LEDs in his sales thread here:
http://www.cpfmarketplace.com/mp/showthread.php?t=169435

Let me know if anyone else is selling K2s and I will post it here.


----------



## Nos (Feb 26, 2009)

btw, look what ive found .... *LUXEON K2 LXK2-PWC4-0220 TFFC

*300 lumens @ 1,5 A 
and they offer a 3° 60mm optic for the K2 too :green:


http://www.leds.de/p709/High-Power_LEDs/LUXEON_K2/LUXEON_K2_LXK2-PWC4-0220_weiss_300lm_TFFC.html


----------



## HarryN (Feb 26, 2009)

Those might in fact be reasonable numbers.

If you look at the K2 TFFC data sheet for the -0200 version, the 200 lumens is the tested rating at 1000 ma. The same data sheet shows that the -0200 is rated at a "typical" 275 lumens for 1500ma.

It is not so uncommon for specialty buyers to come up with special bins of LEDs. I managed to get some X bin Lux Vs (with some real effort) when the "typical" was more like a V bin (about 1/2 the output).

The K2 packages are single die based and modeled after the original Lux I and Lux III package, so there are many years of optics out there.

The advantage of single, 1 x 1 mm die packages in general is that they are much easier to focus. The obvious disadvantage is that it is easier to get more light from a larger area 4 die or single large area die - the downside being the engineering needed to achieve a tight beam is "challenging".


----------



## SemiMan (Feb 26, 2009)

HarryN said:


> the downside being the engineering needed to achieve a tight beam is "challenging".



Not challenging, actually impossible. Direct correlation between source size and reflector size to achieve the same angle of beam. Etendue.


----------



## ledstein (Feb 27, 2009)

Future is actually the global exclusive distributor for Luxeon (Lumileds). Every other company or online shop that offers luxeon buys them from future. 

Still dont get your hopes up. Future is not build to deal with small customers because they have "bigger fish" to catch. They are very slow even with companies that buy big time. 

About datasheets and highpower leds in general. Someone should make a website for making compares and tests with all of them. Untill than the only place you can do this is on a online shop: http://www.ledrise.com/index.php?cat=c2_High-Power-LEDs.html


----------



## HarryN (Feb 27, 2009)

Axkiker said:


> Hey someone on here explained how I could calculate my junction temp based on voltage drop for one of the cree leds I was experimenting with.
> 
> Can someone tell me how to do this for one of the k2 leds? I am experimenting with some of the k2's (not the new ones with ttfe or whatever they have now) Im trying to figure out the same thing but im unsure what figures to use. Im pushing them to 1000ma.
> 
> ...



Hi Axkiker, I hope you don't mind if I answer your question in this thread. This is an excellent question for a technical content thread.

I am not sure about using the mv/C aspect to measure temperature of the junction, but there might be an easier alternative method to estimate the junction temperature.

Lumileds quotes the thermal conductivity of the package as 5.5 C / watt. If you meaure the Vf at 1000ma, then drive the LED at the 1000ma, this will provide V x I = power. (watts) Assuming that ALL of the power is converted to heat, then:

Assuming a Vf of 3.5 V x 1000 ma = 3.5 watts.

3.5 watts x 5.5 C /watt = about 20 C pad to junction difference.

This is not really much power to deal with, and it shows why PL is comfortable to use this same K2 package for 1500ma (about 5 watts). The K2 package is much better at heat dissipation then the older Lux III / Lux V package which were also driven at 5 watt levels sometimes.


----------



## Axkiker (Feb 27, 2009)

HarryN said:


> Hi Axkiker, I hope you don't mind if I answer your question in this thread. This is an excellent question for a technical content thread.
> 
> I am not sure about using the mv/C aspect to measure temperature of the junction, but there might be an easier alternative method to estimate the junction temperature.
> 
> ...


 

Okay so im kinda lost which is nothing new.....

Say you did the math and came up with a 20 C pad to junction difference. Would you then take that temp and add it to the ambient air temp. Typically 21 C at my home. which would make junction temp 41 C

Or am I totally off?


----------



## HarryN (Feb 27, 2009)

Axkiker said:


> Okay so im kinda lost which is nothing new.....
> 
> Say you did the math and came up with a 20 C pad to junction difference. Would you then take that temp and add it to the ambient air temp. Typically 21 C at my home. which would make junction temp 41 C
> 
> Or am I totally off?



You are getting closer. There are actually several thermal barriers between the die and the air.

- Junction to thermal pad = approx 20 C

- Path through the thermal adhesive +
- Path to the walls of the light +
- Path between the walls of the light and the air =

Commonly another 30 - 40 C.

So 21 C + 20 C + 30-40 C = approx 80-90 C at the die.

This is true no matter the brand of LED. 

Lumileds has some very handy guides for approximating these results and some examples worked out in their Application Briefs linked here:

http://www.philipslumileds.com/solutions/portablelighting

Just click on Application briefs, and download AB 05 (Lux III) and AB 23 (Lux V). They are about 5 - 6 years old, but still valid in general, its just that the K2 package is 5.5C/watt vs the Lux V was 8 C / watt.

You don't need to understand it all to follow the pre-worked out examples and the test results.

This is more or less similar to any other power electronic device. As any electronic device gets hot, its performance will often slightly degrade and the reliability will decrease.

It's kind of funny with regard to reliability and the old Lux V. Lumileds took a lot of flack for having a 500 hr rating on that LED package (intended use - flashlights). I added up one time how many times I would have to charge up and completely run down my Lux V light to have it degrade to 70% output - it will never happen.


----------



## blasterman (Feb 28, 2009)

> just a place to post concentrated information the K2


 
What's the CRI of a warm-white K2/TFFC? Can't seem to find the answer anywhere.


----------



## maxspeeds (Feb 28, 2009)

If I remember correctly, K2 TFFC has a typical CRI of 70. Not sure on their warm bins :tinfoil:


----------



## blasterman (Feb 28, 2009)

Yeah...I know the cool tint has a CRI 70, but I can't find a reference for their WW. *Usually* these are higher, but I want to see it spec'd first before I try them for fixed lighting. 

A low CRI just means they're pumping specific spectra to meet benchmarks, not light quality.


----------



## HarryN (Feb 28, 2009)

blasterman said:


> What's the CRI of a warm-white K2/TFFC? Can't seem to find the answer anywhere.



Hi Blasterman, I didn't know the answer so I took the time to look at their web site for you.

Here is a link to the web page for the K2 and K2 with TFFC:

http://www.philipslumileds.com/products/luxeon/luxeonK2

and here is a link to the K2 data sheet:

http://www.philipslumileds.com/pdfs/DS51.pdf

They did rather bury the answer, but on page 8 of the data sheet, note 5, it lists the CRI for the K2 as:

Cool white = 70
Neutral white = 75
Warm white = 80

AFAIK, there the K2 TFFC is only available in Cool White right now. If a CRI of 80 is sufficient, then maybe the WW K2 would work for you.

If you are looking for an even higher CRI with "nearly identical incan like output, there is a product specifically for this application, but currently only in a Luxeon I format.

The datasheet is here:

http://www.philipslumileds.com/pdfs/DS23.pdf 

and a spectral output graph is on page 9.

It is not high output at all and based on the older Lux I package, but if your goal is to mimick an incan, this is your ideal part.

IMHO, if your goal is to have: 
- LED based general lighting
- high efficiency
- high color quality (not just high CRI, which can be tricked)

You are always better off to use color mixing than to buy a white LED, regardless of brand. 

There are a lot of people that like to use an RGB based color mixing, which is pretty good at fooling your eyes, but I am still a big believer in using at least 9 colors in general lighting, starting at around 450nm (or lower if you can get it) and on up to around 670nm (very deep red).

Just drive them in series at 750 - 1000ma and it will beat most white LEDs in almost every measurement.



blasterman said:


> A low CRI just means they're pumping specific spectra to meet benchmarks, not light quality.



Often this is true. The data sheets for most power LEDs show the spectral graphs so you can get a better picture of this. Most white LEDs are deficient in red and red / orange, so you can get a lot of benefit from a cool white in series with a red and red/orange. The highest output red and red/orange that I know of is their Lux III line - massive die in those packages.


Its funny, I didn't even have to look hard to find this info. Maybe I should go work for an LED company. :thinking:


----------



## Axkiker (Feb 28, 2009)

HarryN said:


> You are getting closer. There are actually several thermal barriers between the die and the air.
> 
> - Junction to thermal pad = approx 20 C
> 
> ...


 

hey first off thanks so much for helping me figure out all this crazy stuff. I never would have imagined there was this much to learn.

So tell me is this all sounds correct.

I set my led up and allowed it to run for roughly 30 min to make sure it was up to temp. Then I set the current at 1000ma. I then took a voltage reading and came up with 3.94V

So I take 3.94V x 1000ma = 3.94W

3.94w x 5.5C = 21.67c

21.67c + ambient temp 22c + 40c = 83.67c

So from my understanding 83.67c is well within acceptable range for the k2's

am I on track

thanks


----------



## HarryN (Mar 1, 2009)

Axkiker said:


> hey first off thanks so much for helping me figure out all this crazy stuff. I never would have imagined there was this much to learn.
> 
> So tell me is this all sounds correct.
> 
> ...




Yes, this looks correct. Of course, the 40 C delta from the pad to air is an estimate, but yes, you are fine. Pretty much any old flat piece of Al that has 6 x 6 inches will do this for you.


----------



## Axkiker (Mar 1, 2009)

HarryN said:


> Yes, this looks correct. Of course, the 40 C delta from the pad to air is an estimate, but yes, you are fine. Pretty much any old flat piece of Al that has 6 x 6 inches will do this for you.


 

Okay well then maybe I am off again because im not using a heat sink nearly that big.... I didnt realize the 40c was based upon a heat sink that large.

Im just trying to figure out a way that I can experiment with heat sinks and get an estimate as to the junction temp. This way I can determine the layout and design of my fixture.


----------



## HarryN (Mar 1, 2009)

My number was just conservative.

If you are looking for just a way to do some proto work safely (as in, not kill the K2), then you can go with less.

Example - I have a "test bed" that is made from a 2 x 4 with a piece of threaded rod sticking out. The rod sticks out about 4 inches and the untheaded center of the rod is about the dia of the thermal pad. So - how well does it work ? The steel ones will not keep up with a Lux V but an Al one will.

The threading is handy - sort of like fins.

It sounds like you are attempting to understand and compare the performance of various thermal adhesives. As you note, there are a variety of them out there. I spent a lot of time on this in the past, so if you don't object, I will throw out my "experiences". (all at least 2 year old info using Lux III and Lux Vs)

a) Adhesion vs flexible
- The adhesives that were the "strongest bond specs" were "inflexible"
- At approx 1000 psi, the bonds were rated as flexible, at 2-3K psi, they were rated as inflexible.
- I only tested materials with a manufacturere's spec bond rating, and AA did not provide this on any of their products at that time. Not sure about now.
- I did some unscientific testing to attempt to debond these from mechanical shock, and flexible always won for adhesion.

b) Preclean or not
- Precleaning the thermal pad with pharaceutical grade iso propanol also always won for adhesion.

c) Thermal Transfer
- It is very hard to really double check the thermal adhesive specs (at home), easier in a real lab
- Curing while under pressure helps keep the bond line thin.
- I think you can just solder these K2's to the pad, so that is easier.

Testing method
- Once again, unscientific, only 2 - 3 samples of each material
- I made up an example board, heat spreader, etc and did the full mounting
- Test 1 involved throwing the parts up into the air as high as I could and letting them fall on the concrete driveway multiple times until failures occurred. (parts physically fell off) :naughty:
- Test 2 involved throwing the assemblies against a stone wall as hard as I could from about 10 ft until failures occurred. :naughty:
- Test 3 involved a hammer and chisel impacting sideways at the bond line. (only used on bonds that survived the first 2 tests. The hammer won, but did show very easily the value of the pre-clean)


Based on my limited experience, I would use a 2 part epoxy with about 1000 psi bond strength and listed as a "flexible" bond, precleaned with decent rubbing alcohol. These were brand name thermal epoxies recommended on the Lumileds data sheets at the time.

The good ones were VERY hard to debond. :thumbsup:


----------



## Axkiker (Mar 1, 2009)

HarryN said:


> My number was just conservative.
> 
> If you are looking for just a way to do some proto work safely (as in, not kill the K2), then you can go with less.
> 
> ...


 
Actually I am experimenting with different types of heat sink materials. Not thermal adheasives. I have a material which is an epoxy base that is meant to dissipate heat once hardened. You can vary the mixture and additives to create more or less heat dissipation properties. So im trying to create the mix which works best for my situation. However until I have a way to measure junction temp I dont know if im dissipating enough heat.

am i making sence


----------



## blasterman (Mar 1, 2009)

> They did rather bury the answer, but on page 8 of the data sheet, note 5, it lists the CRI for the K2 as:
> 
> Cool white = 70
> Neutral white = 75
> Warm white = 80


 
Thank you - appreciated. The Cree Warm Whites have a CRI of 80, so I have a frame of reference now. 

80 is fine for general fixed lighting needs, which is why the Cree is popular, so if I experiment with the K2/TFFC color quality needn't be an issue because it seems the K2/TFFC is on par. Those who think CRI isn't a big deal should put some older Luxeons (CRI 70) in their living room and note how the color is awful.


----------



## ledstein (Mar 2, 2009)

TFFC is getting started very well now(after 18 month of uncertain information), large quantities are available. Neutral white (LUXEON K2 LXK2-PWN4-0140, white, 195lm) is available too but only in low brightness. For usual white even very high brightness of 0220 are available in large quantities and some small quantities of 0240 have been "seen around" 
The main advantage of K2 LEDs in general is the extreme heat resistance. These LEDs can be used at junction temperature of >150°C at which other LEDs are already literally melting.
Especially if using narrow focused optics the K2 can be way better then the MCE, because the light output is much more equal thanks to only one chip.
In terms of CRI the TFFC and usual K2 don't seem to be very much different and are the usual average type.


----------



## Axkiker (Mar 2, 2009)

So I think im still lost here. Since im dealing with a heat sink material which has never really been used as a heat sink is there a way for me to calculate junction temp. Either by voltage drop or whatever way you all can fill me in on...


----------



## HarryN (Mar 3, 2009)

Hi, there are a couple of ways to approach this very interesting challenge. Here are 3 that I can think of:

a) Compare the range of thermal properties to known materials used for LED heat spreaders.
- Copper and silver are great
- Aluminum is nearly always good enough
- Titanium is marginal at best, which is why Ti lights often have copper slugs and other tricks in them.
- Steel is marginal but can be made to work in non critical applications
- Compare the thermal conductivity of these materials to your target materials to see if they are practical.

b) Experimental determination
- Perhaps consider replacing the LED with a resistor and a thermo couple
- This is much easier to test and measure

c) Hire an engineer experienced with thermal analysis software simulation to do the calculations
- I used to do this kind of work in college by hand - no more
- A modern thermal analysis by a skilled engineer is quite enlightening, and frankly mandatory if you are running close to the limits.


----------



## asdalton (Mar 3, 2009)

Axkiker said:


> So I think im still lost here. Since im dealing with a heat sink material which has never really been used as a heat sink is there a way for me to calculate junction temp. Either by voltage drop or whatever way you all can fill me in on...



For the thermal resistance of the heatsink itself, see this thread. Basically, any reasonably designed heatsink is going to have a very small thermal resistance.

The largest thermal resistances--and therefore the largest temperature increments--are normally going to be in the die-to-heatsink path (due to low cross-sectional area for conduction), and in the flashlight-to-air path (due to a low heat transfer coefficient).

This rule doesn't apply if there are design deficiencies, such as a very thin heatsink, or a poor connection between the heatsink and the flashlight body.


----------



## HarryN (Apr 21, 2009)

Hi - Tebore was kind enough to point out to us that there is a new K2 / K2 TFFC data sheet - listed here: 

http://www.philipslumileds.com/products/luxeon/luxeonK2

The most interesting part is that Lumileds seems to be close to releasing the K2 TFFC version for warm and neutral white, as these are now listed.

I personally like the WO bin for flashlights (somewhat pale for some tastes) but having the warm and neutral tints is a nice addition to the product line.

It would be great if people can continue to post K2 and K2 TFFC information in this thread.

We can start another thread for the Rebel if anyone wants to do that.


----------



## europachris (Apr 24, 2009)

Well, I received a pair of 220 lumen cool white TFFC and a pair of 180 lumen neutral TFFC from Future the other day.

I've not opened the packages up yet - but WOW!!! oo: Sealed foil packages that must be filled with something because they are a lot larger than two little LED's. What's the deal with the moisture issue and the need to mount the emitters prior to a certain time once the package is opened?

Anyway, I plan to swap the non-TFFC K2 in my ROV Extreme 2xAA adjustable focus light with probably one of the 220 cool white emitters and also swap out the Lux I in each of the Dorcy PR drop-in modules I have, maybe a neutral white in one and cool white in the other. The Lux I emitters that are in the Dorcy modules have a rather greenish/bluish tint - not terrible, but not very nice, either. The TFFC should make a nice output upgrade, also.

Chris


----------



## tebore (Apr 24, 2009)

europachris said:


> Well, I received a pair of 220 lumen cool white TFFC and a pair of 180 lumen neutral TFFC from Future the other day.
> 
> I've not opened the packages up yet - but WOW!!! oo: Sealed foil packages that must be filled with something because they are a lot larger than two little LED's. What's the deal with the moisture issue and the need to mount the emitters prior to a certain time once the package is opened?
> 
> ...



You don't really need to worry about the moisture if you're just doing old fashion soldering of the legs. However with reflow soldering you need to use the LEDs right away once they are out of the package or they need to be baked. The reason for this is the small amount of moisture will steam up and possibly blow the dome off when you reflow. 

Thanks for the heads up on the neutral whites I'm gonna have to take a look.


----------



## LED Boatguy (Apr 24, 2009)

HarryN said:


> Hi - Tebore was kind enough to point out to us that there is a new K2 / K2 TFFC data sheet - listed here:
> 
> http://www.philipslumileds.com/products/luxeon/luxeonK2
> 
> The most interesting part is that Lumileds seems to be close to releasing the K2 TFFC version for warm and neutral white, as these are now listed.


 
Not a stellar CRI

Snip

5. Typical CRI (Color Rendering Index) for CoolWhite and NeutralWhite products is 70, and for WarmWhite product is 75.​ 
/Snip


----------



## tebore (Apr 24, 2009)

LED Boatguy said:


> Not a stellar CRI
> 
> Snip
> 
> ...



It's not worse than SSC's or Cree's cool whites. The efficiency is certainly better than SSC's warm and neutral. I'd say Cree has the best compromise in terms of efficiency vs color and CRI. With TFFC tech coming in second in the area of LEDs with small footprints.


----------



## LED Boatguy (Apr 24, 2009)

tebore said:


> It's not worse than SSC's or Cree's cool whites. The efficiency is certainly better than SSC's warm and neutral. I'd say Cree has the best compromise in terms of efficiency vs color and CRI. With TFFC tech coming in second in the area of LEDs with small footprints.


 
Sorry, I should have said less than stellar CRI on neutral and warm whites. SSC claims 93 CRI on neutral and warm P4s. Footprints weren't an issue when I made 4' strings to replace the fluorescents in the kitchen, but they sure are in other projects. 

We all know cool whites suck in the CRI department. I've quit buying them altogether.


----------



## tebore (Apr 24, 2009)

LED Boatguy said:


> Sorry, I should have said less than stellar CRI on neutral and warm whites. SSC claims 93 CRI on neutral and warm P4s. Footprints weren't an issue when I made 4' strings to replace the fluorescents in the kitchen, but they sure are in other projects.
> 
> We all know cool whites suck in the CRI department. I've quit buying them altogether.



The only downside with the SSC warm/neutral whites is they are only as efficient as the best Lux III. 

I use them and I like them but the hit in efficiency is much too much. I'd take a CRI of 80 with a 85lm/350mA over it. 

As you know CRI comparators only work on sources within the same Kelvin color temp so a warmer light will have better color rendition then a cooler source. 

I agree in Fixed light footprint doesn't matter as much in fact a bigger foot print (and apparent die size) is better when you want it defuse but in a flashlight we want the opposite.


----------



## europachris (Apr 25, 2009)

UPDATE: I swapped the non-TFFC K2 in my ROV Sportsman "Extreme" 2XAA light (the adjustable focus one) for the TFFC 220 lumen cool white from Future last night. HOLY CARP!!!!:wow:

The light advertised 100 lumens, which was total bunk. A Rebel 60 outperformed it. Now, it SMOKES a Rebel 60 handily and turned a mediocre light into quite a performer. Tint is beautiful, similar to the Cree in the Energizer 1xAA, just slightly on the cool side of white. The TFFC die does give the beam some tint variation compared to the non-TFFC - very similar to the Rebel beam out of the River Rock 2xAA Nightfire. I'd estimate it doubled the light output on the same current draw (about .45 amps from fresh AA)

I can't wait to replace the Lux I emitters on the Dorcy PR drop-in modules I have - they are weak and have a nasty greenish-blue tint which isn't so bad until you compare it to something better.

Chris


----------



## HarryN (Apr 25, 2009)

europachris said:


> UPDATE: I swapped the non-TFFC K2 in my ROV Sportsman "Extreme" 2XAA light (the adjustable focus one) for the TFFC 220 lumen cool white from Future last night. HOLY CARP!!!!:wow:
> Chris



Yes, those K2's are pretty impressive.

I was wondering - I only see K2 emitters as being in stock at Future - for Stars, it says "call". I just wondered if anyone is buying K2 stars or if people are just making their own ?

Thanks

Harry


----------



## tebore (Apr 26, 2009)

I was able to order some tffc k2 neutral whites emitters. So the the neutral whites and warm whites are available.


----------



## HarryN (Jun 16, 2009)

Hi, I thought I would bump this thread. It is handy if we can keep the K2 and K2 TFFC questions and info in one thread. :twothumbs


----------



## Blindasabat (Jun 18, 2009)

You ought to add to the first post that K2 TFFC Neutral 180L @1Amp is availble at Future.

Also good to know would be the Amp capacity & actual tested heat tolerance of the K2's. MWClint has been running one 2.4Amp and I have run one (a TVOD) at 2.0-2.2Amp max (so far) DD off an IMR123 (3.8V no load tested - partially used). The droop is very minimal, which increases the actual efficiency compared to less droop resistant LEDs.


----------



## HarryN (Jun 19, 2009)

Hi, Thanks for the info - I added it to the first post per your request.

I did some searching on the 2 - 2.5 amp drive data on the K2 that you mentioned and came up short. Do you happen to have a link or can you post more info here please ?

Thanks

Harry


----------



## HarryN (Jun 20, 2009)

Blindasabat said:


> You ought to add to the first post that K2 TFFC Neutral 180L @1Amp is availble at Future.
> 
> .



Hi, I am having trouble finding these on the future web site. Can you give me a link? Thanks HarryN


----------



## Blindasabat (Jun 22, 2009)

Go to this page:
http://www.futurelightingsolutions.com/products/luxeon/
then click on the green "Product Listing" button for K2 TFFC. I can't link to that actual page because it is a funny pop-up chart. The 180 Neutral is clickable and shows inventory on the product page. The 200 Neutral is listed, but not (yet) a clickable link to a product page.
Their site is hard to navigate and I had to search to find this page the second time, so I book marked it. This is the page that should come up when you click on Luxeon LEDs, but it isn't.:candle:


HarryN said:


> Hi, I am having trouble finding these on the future web site. Can you give me a link? Thanks HarryN


----------



## old4570 (Jun 23, 2009)

I got one , and put it into a P60 pill ...

From here 

Anyhow , mine pulls 1.4 to 1.5A @ the tail ..

So around 1.25 - 1.35A to LED 

So if these are 200L @ 1A , Anyhow !!!
What I like about it is there is very little if any fade in the first 30 seconds or so , seems very stable .

Beam quality is fantastic , lightbox output is right around my R2's ...
Throw ? But the hot spot is no where near as hot as a R2 ..
Tint is warm , very warm , perhaps a little too warm . 
Will see tonight .. Still daylight ..


----------



## old4570 (Jun 24, 2009)

K2 







R2 








Under driven SSC P7 - L2


----------



## HarryN (Jun 27, 2009)

Thank you for posting those pictues. It is really helpful to have some example LED + reflector / optic examples in this thread.


----------



## HarryN (Aug 25, 2009)

Anyone else have some beam shots with K2 or K2 TFFCs? I am especially interested in some from optics or reflectors in the general range of 20mm dia.

Thanks

HarryN


----------



## HarryN (Sep 29, 2009)

Hi - I am looking for some beam shots of a K2 TFFC with a khatod or IMS 20mm reflector or other similar size setups.

Thanks

Harry


----------



## Curt R (Oct 2, 2009)

The K2 and the K2 TFFC are now dead.

They have been discontinued.

Curt


----------



## tebore (Oct 2, 2009)

That's too bad. Hopefully they'll bring something that has the Lux 3 footprint.


----------



## HarryN (Oct 3, 2009)

Curt R said:


> The K2 and the K2 TFFC are now dead.
> 
> They have been discontinued.
> 
> Curt






tebore said:


> That's too bad. Hopefully they'll bring something that has the Lux 3 footprint.



Tebore - Kurt is just messing with you. The K2 TFFC is going strong.


----------



## tebore (Oct 3, 2009)

HarryN said:


> Tebore - Kurt is just messing with you. The K2 TFFC is going strong.



If it were April fools maybe I'd be the fool. Sadly I don't think Kurt is messing with us. 

http://www.philipslumileds.com/products/luxeonk2/

Looks like LumiLED decided to stop development on the K2 and K2 TFFC.


----------



## HarryN (Oct 3, 2009)

:mecry::mecry::mecry:

Ok, I guess I wondered about it when I saw so much variety coming out in the rebels and hardly anything in the K2 by comparison. (so much tint range, etc)

Nonetheless, the rebel is still a far cry technically from a K2. Twice the thermal resistance, 1/2 the output, far less ability to withstand abuse. I know the rebel has won a lot of design wins, but I didn't think it woudl wipe it out.

Now I am left with very few choices to replace the K2 in a new design. Don't say SS and Cree - There are other considerations that those don't meet for me.


----------



## spencer (Oct 3, 2009)

What doesn't the XP-E meet for you?


----------



## lolzertank (Oct 3, 2009)

spencer said:


> What doesn't the XP-E meet for you?



Color: There is no cyan or royal blue XP-E yet.

Drive current: The Rebel is rated for 1A but the XP-E is rated for 700ma.

Vf: Rebels have amazingly low forward voltages.


----------



## spencer (Oct 3, 2009)

I meant XP-G. It has very low Vf and is rated to 1A.


----------



## Curt R (Oct 3, 2009)

I just made a post in the new XP-G thread.

Curt


----------



## HarryN (Oct 4, 2009)

spencer said:


> I meant XP-G. It has very low Vf and is rated to 1A.



The K2 is rated to be driven at 1.5 amps, and can be driven at 2 - 2.5 amps all day long.

The optics, light uniformity, etc. are all completely different when you change from one LED to another. I have done a lot of optical work with the Lux III, V, and K2 - switching to another LED is a big deal.

I probably am missing something, but I don't even understand how Lumileds can suggest that their K2 customers that are buying 200 lumen parts should switch to buying a rebel at 100 lumens. Maybe they have something else up their sleeve?


----------



## IMSabbel (Oct 4, 2009)

HarryN said:


> The K2 is rated to be driven at 1.5 amps, and can be driven at 2 - 2.5 amps all day long.


Which i guess would just make it more of a handwarmer, as i do not expect it to produce more light at 1.5A than a XP-G at 1...


----------



## Black Rose (Oct 6, 2009)

tebore said:


> If it were April fools maybe I'd be the fool. Sadly I don't think Kurt is messing with us.
> 
> http://www.philipslumileds.com/products/luxeonk2/
> 
> Looks like LumiLED decided to stop development on the K2 and K2 TFFC.


The K2 & K2 TFFC datasheets now have a "Discontinued" watermark across each page.


----------



## bshanahan14rulz (Oct 6, 2009)

K2 LEDs spotted in 2008 audi S5 headlight


----------



## Gryloc (Oct 6, 2009)

So Lumileds must have a deal with Audi, right? They are using the Altilon in the R8's main headlights, plus bshanahan14rulz found the K2 in the headlight surround lighting (DRL's?). Thanks for the information!

BTW, when using Google images to look up related images, I ran into this site that shows a bit more detail on the Audi's LED headlight (pretty interesting). The author said he loves LED automotive lighting. He would fit in at the CPF well. 

-Tony


----------



## coors (Mar 12, 2010)

I recently purchased my first K2 TFFC emitter (on a 20mm star, neutral_200lumens @ 1a, from LEDSUPPLY), and put it in a flashlight that's reflector was made specifically for the Lux III-"joker" emitter. Here is a beamshot showing the way that the K2 focuses, when the rear of the reflector is right up tight against this emitters shoulder (the surface surrounding the dome): 






I'd like for the hotspot and corona to not be seperate, like in the above image, but rather one narrow center spot with even brighter spill. I think that the mcr20 Seoul reflector will give me what I want. Does anyone know if the K2/mcr20s will give me what I'm looking for?
Also, want to add that this is my favourite neutral tint that I've tried. Have also used Cree 5a (too pink), Cree 7c (too warm) and Cree 5c (my favourite tint 'til this Luxeon).


----------

