Seoul P4 initial Evaluation- Production LEDs

[Doug S]

Jar, there sure is a bunch of great eye candy for us technical types in this thread. Thanks. BTW, there is a discrepancy [typo?] in your post #207 w.r.t your numbering of the funky emitter; #1 vs #2.
I find the graph you posted in #204 to be interesting. At least with this sample the temperature plus current color shifting very closely parallels the BB planckian locus more so than I recall from data you published long ago for other power leds though possibly this may be just due to the different range of currents in the two datasets.

[NewBie]

Could you elaborate on the typo? Are you talking ( ) or funky and Funky?

The tint shift direction does vary a little bit, depending from which bin you start off at. I wouldn't take this as a rule, the tint shift direction, but as a stereotype. I've ran some Philips LumiLEDs Luxeon III XO bins that follow or parallel the line closely also, but not every one of them shifts identically. The left and right are generally similar, with some variation of the parallelism from one LED to another, from what I have seen in the past. Other color bins have more departure from parallelism, but I have not ran a big enough sample. Sorry guys, I'm not going to run a bunch of these for color, it takes many hours to do...

Here is the XRE chart below, and I'll see what I can dig up on the Luxeon tonight, if I remember.

[Doug S]

BTW, there is a discrepancy [typo?] in your post #207 w.r.t your numbering of the funky emitter; #1 vs #2.

Could you elaborate on the typo? Are you talking ( ) or funky and Funky?

Sure. Text describes #1 as the funky one but graph labels #2 as the funky one.

[NewBie]

The funky one is in light (bright) green.
In the first graph (Vf) it is labeled as:
Seoul P4-T lot1 #2 (funky)
In the second graph Relative Brightness it is labeled as:
Seoul P4T Lot1 #2 Funky

That is the second real odd ball part I've found in 10 so far (leaky=funky), and also the two more 700mA tint shifters, but at higher current levels the one that started feeling blue around 500mA.

Am I still missing something?

[NewBie]

Okay, finished up three more Seoul P4 emitters, nothing odd found (good thing!)

All the Seoul P4-T Lot1 parts are from the same Intensity, same color bin, and the same single Vf bin. One of the nice things about buying reels, they label exactly what is on the reel, on the reel.

The series I am starting on now, are all Seoul P4-U, and are from the same Intensity, same color bin, and the same single Vf bin. In fact, they are from the same Vf, and color bin as the Lot1 parts.

Anyhow, updated graphs:

[B@rt]

Hmm, looks like someone has been busy taking measurements...

[limks]

Great review. Many thanks.

[NewBie]

Okay, I've updated the Vf chart with the results of the rest of the Seoul P4-U bin. The Vf bin for lot1 and lot2 is 3.25V - 3.50V and Seoul P4 binning is done @ 350mA.




I've expanded the Vf plot a bit:




And the Relative Brightness chart:




One of these last four U bins was below the T bins. Otherwise, you can see a slight split up at 1000mA, between the T bins and U bins. Generally, the U bins have a higher Vf than the T bins.

[easilyled]

FYI, I rinsed off the Seoul P4 again, it keeps reaching out and grabbing dust out of the air... : (

If I decide to use many of these, I might think about making my own mini laminar flow bench, along with a +/- ion generator for equalizing charges to help keep the static down. Besides rinsing with water or isopropyl alcohol/water mix, anyone come across any great ideas on removing/preventing the dust collection on the Seoul P4?

I had an idea for removing the dust but its only hypothetical since I haven't
actually had any of these leds to play with yet.

I was wondering whether making a loop of sellotape, sticky side out,
then very lightly applying the sticky side to the gummy dome to remove
dust would work.

Please bear in mind that at this point I don't know how delicate the
gummy dome is.

[NewBie]

I have some more K2 parts and Luxeon III parts that I think I might run a couple of curves on tonight, just for additional comparision.

I would be interesting to blast it with one of those de-ionizing compressed air guns usually used for static neutralization, to see if it would reduce the miracle dust magnet personality.

[MikeSalt]

I think I'll stick by Cree. Any flashlight that permits access to the LED module will allow dust to settle on the 'gummy bear' lens. Eventually, 240 lumens through a few microns of dust will not only reduce output, but will also make the module heat up under refelection, causing premature failure.

[EngrPaul]

A little dust won't stop me. All you have to do is a final cleaning and air blast before assembly, including front glass, reflector, and emitter. I do that anyway.

[MikeSalt]

My point is this. SureFire will have known about both the Cree XR-E AND the Seoul S4 due to their excellent research department. Being the premier manufacturer of flashlights, they will have considered and researched all factors including quality of beam, CRI, lack of tinting, durability etc... And after several $10,000s of consideration, they have stuck with Cree for a reason. With your reputation at stake, you pick the best, not necessarily the brightest.

[hotbeam]

Eventually, 240 lumens through a few microns of dust will not only reduce output, but will also make the module heat up under refelection, causing premature failure.

I think that is way over dramatisation.

[nightrider]

Great work Newbie. I've been following this thread from the start... lots of nice photos and discussions.

Any chance of getting an XR-E and a Luxeon III thrown in the Current vs Intensity chart?

Thanks.

[McGizmo]

My point is this. SureFire will have known about both the Cree XR-E AND the Seoul S4 due to their excellent research department. Being the premier manufacturer of flashlights, they will have considered and researched all factors including quality of beam, CRI, lack of tinting, durability etc... And after several $10,000s of consideration, they have stuck with Cree for a reason. With your reputation at stake, you pick the best, not necessarily the brightest.

[3rd_shift]

My point is this. SureFire will have known about both the Cree XR-E AND the Seoul S4 due to their excellent research department. Being the premier manufacturer of flashlights, they will have considered and researched all factors including quality of beam, CRI, lack of tinting, durability etc... And after several $10,000s of consideration, they have stuck with Cree for a reason. With your reputation at stake, you pick the best, not necessarily the brightest.

Welcome to cpf.
Interesting points.
Some of which I'm inclined to agree with already.
It would still be interesting to see if SSC comes up with a better material for the led dome.
As of right now, this led seems more at home inside a "sealed" flashlight, or lighting device.
It would not be a good choice (for example) in a C, or D Maglite mod where the head is easily removed, as dust would be a near instant issue for the led.

PS;
Have a look at some of McGizmo's work.

[NewBie]

Great work Newbie. I've been following this thread from the start... lots of nice photos and discussions.

Any chance of getting an XR-E and a Luxeon III thrown in the Current vs Intensity chart?

Thanks.

Sure, I got home early tonight, so I'll hop on it right after I finish eating dinner.

[yaesumofo]

Please explain your statements.

Do you have any proof that would support this statement?
Wouldn't the same be true of the cree emitter if some dust settled upon the glass lens of the XRE? If not why not?
Somehow I don't believe that dust (in small quantities) has any negative effect upon the durability of either of these emitters or any of the Luxeon emitters, for that matter. This is based upon the fact that I have never seen a failure of a emitter due to dust. I have plenty (100+) of LED based flashlights. Some even have tiny specs of dust right on the emitter. None have failed. In fact I would go out on a limb and say that the dusty emitter is more likely to fail because of botched attempts to clean them than the dust itself. I have several lights which run HOT (ARC LS) none have failed due to heat yet.

Yaesumofo

Any flashlight that permits access to the LED module will allow dust to settle on the 'gummy bear' lens. Eventually, 240 lumens through a few microns of dust will not only reduce output, but will also make the module heat up under refelection, causing premature failure.

[yaesumofo]

I think this is the understatement of the centrury.
Yaesumofo

I think that is way over dramatisation.

[NewBie]

Yaesumofo,

The Seoul P4, and the way it actually pulls dust out of the air is really very uncanny. I've never seen anything like it. Whatever they did, they could make a product out of whatever they used and market it to housewives.

But, you can clean it, and get it into a sealed light.


Anyhow, back to testing...and we have updated graphs...


I tested a number of Luxeons and tossed them on the graphs below:



Take note of where the Seoul P4 Vf fall in reference to the K and H bin Luxeons, above.







The light output comparision above is very interesting, especially when you compare the various bin Luxeons to the Seoul P4 which uses the CREE die.

[ViReN]

I've expanded the Vf plot a bit:




And the Relative Brightness chart:




One of these last four U bins was below the T bins. Otherwise, you can see a slight split up at 1000mA, between the T bins and U bins. Generally, the U bins have a higher Vf than the T bins.

NewBie, Thank for the great efforts. It is highly appreciated.

EDIT: Since you have compared Vf of Luxeons and Crees... It seems logical for me to look for intensities at various currents of others as compared to Seoul SP4. After all intensities (is what matters to most ppl) should also be compared apart from the Vf's. without the Intensities of others compared, the SP4 intensities chart remains incomplete.

Would it be possible for you to include the Intensities of others like Cree's and luxeons as well when comparisons intensities?

EDIT: Doh... its already done Thanks NewBie .... just one request still ... if possible it would be great if you could include Cree's P4 or P3 bin too for the brightness comparison with SP4

[ViReN]

the above charts are so helpful... wow...

Imagine.. what brightness (100) TWOH can achieve with 900 mA can be achieved by roughly any of Seoul SP4 with 250 mA.. yes Vf @ 250 mA

Compared Vf at same Brightness may be near or around 3.3 V for both the cases.

So that means Seoul P4 is still more efficient by at least 900/250 = 3.6 Times !!!

Time to get some Seoul P4's..... .... hmm.. who'z got them?.... let me visit sandwich Shopie

[3rd_shift]

Newbie,
just for giggles when you have time, can you toss in a Luxeon5, or two?
It looks like the SSC and Cree XRE leds could give even, a good Lux5 a run for it's money.

[NewBie]

Okay, I've made another graph to put things in perspective.

Current does not tell all about an LED.

To the converter and battery, what really counts is the power it consumes, which is known as Watts. Watts is the product (multiplication) of Voltage times Current.
W=V*C (aka P = V*I)

So, I've taken the Power consumed and plotted it against the light output on the vertical scale below:




There are enough datapoints there, that it is getting hard to make things out, so I've produced a larger version of the graph that you can use, download it here:
http://www.molalla.net/~leeper/sp4int3.png

On the larger graph, you will notice that there are some kinks in the lines, which were due to the resolution of the readings on the early parts. I tore apart the power supply and added dual 10 turn potentiometers on the current adjustment, which allows for much finer adjustments, so the later measurements are much smoother, as well as utilized different meters for better resolution.

I have the Seoul P4-T that is still mounted to the heatsink, which allows me to verify the setup is correct, before the start of each set of measurements, it is my reference to ensure consistency.

Both lot1 T and lot2 U are all from the same Vf and tint bins. Lot1 T is specificed as 70-90 lumens, and lot2 U is specified as 90 to 110 lumens, both at 350mA.

I hope to get to the CREE tonight, if time permits. I should say CREE XR-E, since the Seoul P4 also uses the CREE die...

[CM]

Newbie,
just for giggles when you have time, can you toss in a Luxeon5, or two?
It looks like the SSC and Cree XRE leds could give even, a good Lux5 a run for it's money.

Please pardon me for chiming in to your question to Newbie. I've modified several KL6's with Crees. As far as giving the Lux V a good run for the money, it's comparable to a W bin Lux V when biased at 950mA. It's brighter than any of the stock KL6's which probably use a V bin. This equates to about 30% less power than a premium bin Lux V but having an output that is about the same. Throws a heck of a lot better too. I have no intentions of buying any more Luxeon based lights until Lumileds can up the ante.

[ViReN]

I have no intentions of buying any more Luxeon based lights until Lumileds can up the ante.

I wont buy either... even the ante Luxeons... Until NewBie Tests em

Great Work NewBie, It's really helpful to many of us and saves a lot of $$$.

Your work is highly appreciated.

ViReN

[NewBie]

Okay, well, I tested a second CREE, which is #2 on the overkill heatsink.

CREE #1 is already mounted on a 2" by 3" by 0.165" piece of copper sheetmetal only.

The device used for "brightness" testing was an Extech 407026 mounted to a white pail, such that the light from the LED would not have a direct path to the sensor. LED was inserted in a hole in the jug.

Meter here:
http://www.extech.com/instrument/pro...50/407026.html


Caveats:
-Like all light meters, it is not a spectroradiometer, and will have some error depending on the spectral output of the LED. Expect any errors due to spectral differences between LEDs to cast doubt on accuracy of measurements.
-CREE #2 was not mounted on the overkill heatsink, and it's thermal solution is different than the rest of the LEDs under measurement.
-CREE LEDs were both directly soldered to copper, NOT a MCPCB.
-The CREE LEDs were both from the "low output" P3 bin (73.9 - 80.6lm), NOT the Q3 bin (93.9-100.4 lm) which would be in the Seoul P4 U bin range (91.0-118.5 lm).
-CREE #1's bin appears to be higher than what the vendor that supplied said it was. Possible mixup at the vendor.

For the testing to be fair, I'd need to obtain parts from the same lumen bins from Seoul and CREE. This comparision here is a bit biased, as I do not have any Q3 bins from CREE yet. Some folks have been running around saying the Seoul P4 is brighter than the CREE XR-E, which is dicey at best to say, since we are not comparing the same lumen bins. Of course a part from a higher lumen bin will be brighter!!! It may be that companies are paying premium for the top end CREE bins, like Surefire, and thus the lack of availability- *conjecture on my part*.


Anyhow, the new graphs:




The BIG version:
http://www.molalla.net/~leeper/sp4int3.png


.

[Gryloc]

Newbie,

I just want you to know that I really like the Seoul P4 LED! I ordered one from Mouser (just a T-bin) and it is just awesome. Comparing side by side to a TWOH LuxIII, the color is a bit more blue, but not too much. By it's slight sky blue tint, I would say it would be in the Luxeon YO range, close to the XO area.

The brightness is just amazing!! I have a few new crees now, but I just realized just how hard it is to use in flashlights. Very few reflectors work with it, and the only optic I have, the Cree XR-E TIR optic, isn't at all impressive.

I have the P4 here and it does work well with different reflectors, such as the D cell Maglite and the different IMS 20mm and 27mm reflectors. I decided to throw this P4 into my very first true flashlight mod that I created. I modified the Streamlight Tasklight 3AA Luxeon to handle a Fatman driver and a V-bin LuxV. This thing seemed bright back in the day, but over time, it dimmed, and the LuxIII was beginning to put it to shame. So, I decided to retire the poor, tired LuxV and give the thing an upgrade.

The Fatman driver in this thing has a messed up trace somewhere, so the built on trimmer does not work right. The circuit wont sense any resistance so it will not limit the current. With a fresh set of batteries, the Fatman will try to dump as much current as it will allow into the LED. For the LuxV, it didn't phase it any because it had such a high Vf. With the P4, I measured 2.6A at the battery and 1.7A at the LED. Of course, I used the amp-meter function of my multimeter, so the current will be a little higher (will be ~1.10 times more normally). With these high currents, I notice that the tint shifts a bit more blue after being on for about 5 seconds. I dont leave this on for very long, but I would like to drain the NiMH's a little so it can be on longer. I may just have to fix the Fatman or replace it if I want to keep using this flashlight.

I seen some people asking to test how hight of a current the P4 and the XR-E can handle. My P4 handles <1.8A without fusing open, but keep it cool! I hear the gummy domes keep the die and phosphor cooler than the old plastic dome, so that explains why I feel the heat on the dome. This is just like the K2. I still need to play with the XR-E. I have three set up on a massive Al heatsink. We'll see...

...Well, what blows me away is the comparison between this light, using the IMS SO27XA, and my quad TWOH Maglite using IMS SO20XA reflectors. The brightness of the two beams look very similar! Seriously! The beam of the Tasklight is just slightly narrower with a larger corona. I really wish I can afford a luxmeter right now!

Here are some beam shots. My ceiling is spackled, but painted with glossy paint.


Here is without any optics at all. This shows the floody light to compare overall brightness. I held both lights up to the glossy painted wall at about 0.5 meters away.
NOTE: try to ignore the reflected light, unless you want to use that as a comparison.

Wow! Sorry my camera cannot be manually set, so everything was in auto.

As proof, here is the setup, even if it is a little fuzzy.

By the way, the poor SO27XA reflector had to be trimmed a bit to fit into the head, so over time, a bit of the reflector material was flaking off. I also tried to clean it once . Additionally, the lens (all I could find at the time) is about 3mm thick and has a chip in one edge. I bet that all this might be hurting the light output a bit. Now I need to get a new Fatman, a new reflector, a new lens, U-bin SSC P4, and Tasklight Luxeon to re-do this thing. It needs to be re-done. Then it will be truely awesome!

Sorry if it sounds like I am changing the topic of things, but I thought I would share my findings. I wish I could have the equipment to test the LED better like you, Newbie. I like all the results that you have come up. The measurements you have come up with are amazing! You work so hard for all of us at CPF and it is just great! Like others have said, keep up the good work.


-Tony

[NewBie]

I fully understand having to grind down the reflector for the Seoul P4, and also having to shim it up ~0.30" to fit into existing solutions. Non-perfect reflectors sure help with a variety of things, and also the rough surface or jeweled ones.

Here is what I got out of a "perfect" MagLite D cell reflector with the Seoul P4:




There are a number of different pictures of the Seoul P4 and various reflectors earlier in the thread, along with some videos of the tint shifting.

I had five of the 13 I tested for this that had various issues. 3 of them would shift extremely blue at 1 Amp. One definitely had a die delamination problem. And I had the leaky one, that drew 50mA and made no light (normally they make light under 1 mA). Above that, it made light, and for the most part, acted like any other Seoul P4, just hampered a bit. Oh, and there was the U bin that put out less light than a T bin.

It is a different beast than the Luxeon III, really smoking the current LumiLEDs parts for sheer light output. It isn't a perfect part, so the white wall warriors will want to keep in mind, do you want lots of light, or a virgin white wall beamshot...

I'm very glad to hear you really like your Seoul P4!

It is a new part, and I imagine it will continue to evolve and improve as they dial things in.