# Seoul voltage bins: USXOI vs. USXOH or USWOI vs. USWOH



## bluecrow76 (Oct 18, 2007)

I just replaced the emitter on my Streamlight Scorpion with a Seoul P4 USXOI from Kaidomain. After it was working and I was amazed at the difference in output, I did a little more looking into the Seoul bins. I'm curious as to the advantages of running a USXOI (voltage bin 3.25-3.5V) versus a USXOH (3.00-3.25V). If I were to switch to a lower voltage bin, would that adversely affect the driver in any way, or would it simply require less voltage for the same output? I'm looking at ordering a few more from Kaidomain and he's offering the USWOH now.


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## Supernam (Oct 18, 2007)

It'll be fine. I put in a USWOH into my Scorpion LED. Check my thread https://www.candlepowerforums.com/threads/177646


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## nanotech17 (Oct 18, 2007)

USWOJ in a fenix LOD (left) vs USXOI in a LF2 (right)


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## tebore (Oct 18, 2007)

In theory the lower voltage bin should be brighter because it's more efficient. 

Say your driver is pumping 3.5v at 700mah then it's at about 2.45W. Say your LED is spec'd 3.0 - 3.25 taking the top of the bin it should be driven 3.25v at 700 which is ~2.28W. The difference is you are "overdriving" it 0.2W. 

The Voltage bin on Seouls are pretty slack so unless you have a really really good driver that is very specific it's the color bin that's more important. 

Most of the H bins I've tested seem to be at the top end of the bin sometime even exceeding it within a margin of error. It's 50/50 with the I bin, some test on the high end and some test on the low end of the bin.


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## Szemhazai (Oct 20, 2007)

Don’t be so certain about binning by Kai, We compared emitters from dx with emitters from official distributor - "U binned dx" was dimmer than T-bint from our local distributor...


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## bluecrow76 (Oct 21, 2007)

Thanks for all the great information!

I tested the USXOI emitter I got from Kai in my Streamlight Scorpion LED after the mod and it was pulling ~3.45 volts. I forgot to do some current testing before I soldered so I'm not exactly sure what current that is it... all I know is it's a heck of a lot brighter. It's on par with my Lumapower M1-XRE Seoul light engine, although the emitter in my M1 is warmer.


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## stuj (Nov 16, 2007)

Hi guys i know this is a bit late and slightly off topic but i'm building a bike light and need to order suitable seoul p4 leds but i just don't know which bin would be best, uswoh usxoh etc .........

i will be using 3 together in 2 lights.

hope you can guide me in some way to choosing the right one

thanks in advance 

Stuart


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## bluecrow76 (Nov 16, 2007)

stuj:
Take a look at this pdf. It's the binning and labeling document for the Seoul P4. Starting on page 5 is the information you're looking for:

Luminous flux (U)
Color coordinates (tint/temperature) (cool, neutral, warm) (SXO, SWO)
Voltage (H, I)

You basically have to pick what tint you want. SXO is cooler (more blue) than SWO. You seem to get "more" light the cooler the tint. You have to find your happy medium.


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## bluecrow76 (Nov 16, 2007)

stuj: Take a look at Nanotech17's pictures in post #3. The cooler tint emitter is on the right. They are also in different voltage bins.


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## stuj (Nov 19, 2007)

thank you very much for the help. sorry for not replying sooner !

so if i want the brightest i can get would that be bin code Y as that has the highest luminous flux i assume @350ma, for pure white colour is W and voltage 3-3.25v so H

the only thing then does this work out as YSWOH

the only thing is everyone seems to be using uswoh, usxoh etc so i'm a bit lost.

thanks

Stuart


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## bluecrow76 (Nov 19, 2007)

stuj: You are correct in your assumption... the only problem is that they haven't been produced yet, which is why the only thing you see people using are U bins. The binning codes are just a list made ahead of time saying this is how we're going to classify them. As they improve the manufacturing process they figure out how to crank more lumens out and then the next bins are born.


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## stuj (Nov 19, 2007)

bluecrow ......

your a star thanks for all the pointers ! 

i think i know where i'm going now.

i have found a fairly cheap uk distributor about £4.53 each their site is www.2k1.co.uk if that's of any help to anyone ?

Stuart


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## stuj (Nov 21, 2007)

before i order it appears as if the sxo are brighter than swo is this correct and also which white is this ?

thanks again Stuart


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## bluecrow76 (Nov 21, 2007)

The only difference between SXO and SWO is the tint... which can affect perceived brightness, but they are so close I don't think you'll REALLY notice the difference. The SXO should have slightly more blue in it that the SWO. I just swapped emitters in two Fenix P1's from the garage sale with USXOH emitters. The color is on the cool side of neutral white and the color rendition is great! I don't think you could go wrong either way!


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