1W "S" bin : IntegratingSphere results

[McGizmo]

AWR,

There was a radical drop in price on the LuxeonIII's as well so your diffrential stated is not really indicative of current pricing. If you want to mix the past with present and future (pun intended) then the LuxeonIII's are on the shelves and in our hands whereas the K2's rotate only in avitars! :nana:

Seriously, the LuxeonIII's and 5W for that matter have been brought down in price and this is reportedly in response to market presure from other mfg's like Seoul Semi.

Elevated temperature capacity looses value of the part uses up this advantage in its own waste heat.

It would seem that Future and Lumileds plans to obsolete the Luxeon III with the K2 and this should be fine provided the K2 can match or exceed the performance of the Luxeon III. Pre production samples have not lent much support to this proposition.

 

[andrewwynn]

well.. every person that's posted results of a K2 Ubin.. something like UWOM or UWON like the samples i got have very similar feedback regarding the Vf and output.. i agree there will likely be advantages of the Lux3 regarding mating with reflectors, but whoa.. 7x the cost per lumen.. time to figure out new reflector solutions :-D

-awr

 

[ViReN]

<snip>
Unfortunately, I didn't keep the Excel Spread Sheet used or I could have just added the S bin sample to the rest. :shrug:

So what I measured on the S sample follows:

If (mA)****** Vf********** Lumens

100 ---------- 3.0-------------- 17
200 ---------- 3.2-------------- 33
300 ---------- 3.3-------------- 46
350 ---------- 3.3-------------- 51
400 ---------- 3.4-------------- 56
500 ---------- 3.5-------------- 65
600 ---------- 3.5-------------- 74
700 ---------- 3.6-------------- 81
800 ---------- 3.6-------------- 88
900 ---------- 3.7-------------- 94
1000 --------- 3.8-------------- 98

It is really important to keep in mind that these measurements are reasonable in terms or relative comparisons among the samples tested but as to how representative any one of these LED's is of its brother bin members, well, your guess is as good as mine. This particular S bin held its own against the measured competiton but did not win in any category; nor did it loose!

Here is the chart

 

[andrewwynn]

very promising to see numbers in the sub-4 for Vf finally! still only 80LM at 700mA.. where the spec. sheet i got showed 700mA and up to 100L for the Sbin.. this is a pretty far cry from that. I don't think i can get the 11+W out of my driver in the minimighty to get 3 of them up to full power at that rate...

I can see lux3's becoming the vinyl records of luxeon lighting as the K2s become the CD.

 

[chimo]

very promising to see numbers in the sub-4 for Vf finally! still only 80LM at 700mA.. where the spec. sheet i got showed 700mA and up to 100L for the Sbin.. this is a pretty far cry from that. I don't think i can get the 11+W out of my driver in the minimighty to get 3 of them up to full power at that rate...

I can see lux3's becoming the vinyl records of luxeon lighting as the K2s become the CD.

Andrew, those are LuxI numbers above, not K2s. I would love to get my hands on some S bin K2s.

 

[NewBie]

Andrew, those are LuxI numbers above, not K2s. I would love to get my hands on some S bin K2s.

It's not nice to spoil dreamers dreams....

 

[andrewwynn]

well, in that case.. i'm still dreaming.. the K2 Sbin spec says 40lum/w and 2.5W =100L, thanks for pointing that out.

-awr

 

[NewBie]

well, in that case.. i'm still dreaming.. the K2 Sbin spec says 40lum/w and 2.5W =100L, thanks for pointing that out.

-awr

Then you need to derate for heat.

 

[andrewwynn]

that is true.. heat kills output.. works out nice with the LDO^3 driver though... it changes output based on temp, and counter-acts the dip in lumen from the lux heating up.. far as i know the only one of its kind out there.

 

[BentHeadTX]

Isn't a S bin 51.8 to 67 lumens at 350mA?
If so, the 51 lumens reading at 350mA is right on the edge of R bin and S bin... not a good S bin at all! Personally, I am not going to worry about it much... it is a LuxeonI and I want S bin K2's that fall in the "average" of the bin at 60 lumens at 350mA and 100 lumens at 700mA.
Just make the voltage an H bin so it can be 3.15V at 350mA and 3.40V at 700mA. If anyone has any, I'll take six of them!

 

[Kiessling]

It seems that there is exactly the problem with the K2 ... the Vin, which is much worse than what we are used to nowadays. And frankly, if a LuxI is (almost) as efficient as new K2 and has a better Vin ... I am not too excited about the K2, especially in "low-power" applications like 350mA.
bernie

 

[jtr1962]

Since it seems semi-relevant to this thread I measured a Seoul Semiconductor 1 watt star (bin RSX0I) a few days ago at 52 lumens and 44.3 lm/W at the rated 350 mA-results nearly identical to Don's S-bin star. Graphs here. I'll also add that SSC claims 52 lumens at 25°C (ambient temperature, not junction temperature) is typical for this part.

 

[evan9162]

that is true.. heat kills output.. works out nice with the LDO^3 driver though... it changes output based on temp, and counter-acts the dip in lumen from the lux heating up.. far as i know the only one of its kind out there.

Current regulators that use the LM334 behave in the same fashion - That's the setup that I primarily use.

 

[hizzo3]

i notice that as the Vin and current increase, the output per watt decreases.....i figure this is due to heat maybe? i think there are too many variables. i'd like to see a test run where the led's were put on a peltier(cold plate/heat pump) plate to pull temp out of the equation. i think this would prove interesting. i'd do it myself, but i dont have the testing equipment. lemme know if any one does this. i think it will show that there is much more output to be had through better heat sinking

 

[IsaacHayes]

http://candlepowerforums.com/vb/showthread.php?t=33596
hizzo3: chcek that out

 

[jtr1962]

This thread also (my amber luxeon cooling experiment).

 

[evan9162]

Note that only the red/orange/amber luxeons benefit from greatly reduced temperatures - their temperature derating curve is exponential, whereas the white is linear with a very shallow slope.

Freezing a white luxeon down to -20C case (~0C Tj at 350mA) only results in a 10% increase in brightness. It's totally not worth it for general use, and is very hard to even see in experimentation (you need a light meter to measure the difference)

 

[hizzo3]

mmm, nice.... i just took a look at the laminas. i know ceramics tranfer heat much better then metals. i guess why they are much brighter per watt. Imagine a bl- 3000 on ice with a pelter.... bet we would hit near that maximum level

 

[evan9162]

Actually, the laminas are a generation behind in terms of Lumens/Watt. They have good thermal characteristics, but seem to be using older dies.

 

[chimo]

Here are the plotted results with the LuxI S bin: