I got the emitters from Arrow and reflowed them on Kaidomain’s 20 mm DTP MCPCBs.
I mounted the emitter on CPU heatsink with a nice splash of thermal paste and over the top 16 AWG wires.
I got two emitter types. They only differ in the flux bin with the MF being higer, but I took both to check if there’s a difference in tint. Spoiler: the KF was nicer, but MF has much higher output potential.
Exact order and bin code:
- SPHWHTL3D50GE4RTMF
- SPHWHTL3D50GE4RTKF
Most tests were done with the MF bin, which most people ordered since it was on sale at Arrow.
Purchase links:
https://www.arrow.com/en/products/sphwhtl3d50ge4rtmf/samsung-electronics
https://www.arrow.com/en/products/sphwhtl3d50ge4rtkf/samsung-electronics
In the product code:
SPH=Samsung Package High Power
WH=White
T=Product version
D=Domed lens
5=LH351C (A=LH351D, 3=LH351B)
0=Not defined
G=CRI min. 90 (C=70, E=80)
E4=Forward voltage bin 2.7-3.1 V
RT=CCT 5000 K
MF=Flux bin 250-310 lm, KF=230-290 lm at 700 mA at 85°C
CRI data measured at 700 mA from the hotspot with a
Yajiamei 10° beaded optics (MF bin)
Yajiamei 10° beaded optics (KF bin), nicer tint with less green (duv 0.003 vs. 0.005 on the MF)
Bare emitter (MF) at straight on (0°) for reference
Medium sized smooth reflector from the Eagle Eye X7 (MF)
CRI data with increasing drive current with the Yajiamei optics measured from the hotspot
1000 mA
2000 mA
3000 mA
4000 mA
5000 mA
Output measured in a 50 cm integrating sphere
At 700 mA I measured 306 lumens at 147 lm/W for the MF bin and 290 lumens at 139 lm/W for the KF bin.
The LH351C is rated at a maximum of 2000 mA and 2600 mA pulse current.
The MF bin I tested produced much higher output at high currents than the KF bin.
MF bin
KF bin
I also found that the LH351C behaves quite well in a clear 5° Yajiamei optic which is rare. There’s just a hint of green in the corona and a very slight pinkish hue right in the middle of the spot. From this I would assume these get along very well with clear Carclo triples and quads, but haven’t had to chance to test them yet.
Small to mid sized OP reflectors work perfectly, but they are very forgiving with most emitters.
Looks like Samsung is giving Cree some real competition. Especially since Arrow had them for a little over a quarter.
I suspect that at some point Cree may start reducing their prices to compete.
Thanks for posting all this test data up maukka, really useful info.
V11R and V10R Current Mod
But Cree has some good below the BBL tint bin options available whereas all of Samsung’s offerings are above the BBL and yellowish/greenish.
Thank you for the testing and report maukka. Such great info. My experience with the tint pattern of the MF emitter with the S41 quad optic is right in line with what you reported.
Thanks a lot for the test maukka. Gonna practice dedoming these very soon.
Cheers
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Can someone recommend a small TIR with very wide spread. If possible a TIR without a visible spot.
Checking the options and prices. Want to build a light (like a lightbar with 6 or 9 LED´s) for kitchens wall cabinets (for my parents). So distance between light and worktable is less than ~60cm.
New WildTrail (former LuckySun) D80v2 Sale has Started http://budgetlightforum.com/node/66255
You don’t necessarily need any optics for that, just a milky/frosted piece of acrylic (or d-c-fix 346-0211 on clear). I really like the Yajiamei optics, and there’s a very large lineup of spotty and floody up to 85°.
Thanks Maukka!!!!
They look nice and they are really cheap. I could bite my ass that i did not order more LED´s (0,30€/led) from Arrow (I only ordered 5 to play with).
But i will have to order some more. Hope to find another order option for the TIR´s. Because i have a problem with Aliexpress. Still working on a refund (after i already spend hour and hours with their support).
New WildTrail (former LuckySun) D80v2 Sale has Started http://budgetlightforum.com/node/66255
maukka – have you ever measured and compared a sliced one?
I did this with the 80 CRI version, I can only estimate but I’d say CCT went from 5000k to <4000k and the slight greenish hue looks gone now
I will have a look when I’m at home later, could very well be
link to djozz tests
Why did The_Driver deleted his post?
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No idea, btw I just checked and I do have some of those leds still.
link to djozz tests
- LEDs & Other Stuff - - UI CheatSheets - - CRX Flashlight Builds - - CRX Stuff for Sale -
You are being nosy
Maybe because I don't need any anymore.
Thanks, I already found some.
These LEDs are very efficient for their size, 90CRI and the possiblity of having a good tint together with high luminance (when shaved). In part this is achieved by a slightly lower R9 value when shaved.
Project Excalibur - Next Generation LED Thrower (UPDATE 2018-01-15: 1.7Mcd)
Portable Thrower Comparison
Nah I'm not noisy, as a rule not even my farts are when needed (because
ninja).
Aaah! You said nosy!
I still have two, wonder what will do with 'em some day. Powered by an XHP70 boost driver a quadkenstein aspheric build sounds appealing to me, albeit one with just two emitters would also do by carefully adjusting the current output.
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How did it go Barkuti?
Wellp, it didn't go. Can't recall what I was planning by the time but I used another emitter. They're still in my emitter cache box.
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I see. I think this LED might have some potential for high CRI throwers. More efficient than SST-20. Also green but dedoming is said to fix that.
But maybe they aren’t so good, it’s hard to tell without knowing die size…or testing.
Any lumen to candela measures done already. Is it more like nichia 219c or sst-20?
I took the picture above and measured die size. Magnified by the dome, about 2.2 mm side. Assuming refraction index of about 1.5 that would be very roughly 3.2 mm².
And it’s flip chip.
So…despite much higher efficiency than SST-20 it’s unlikely to compete….though I would still love to see it dedomed as I have no idea of how good or bad is the calculation method that I used above.
Well, I’m not sure if those will be a throwy ones…
I hoped those could have similar to xl-l hi beam pattern, but now I assume beam pattern should be more or less like nichia 219c.
219c is probably their main competitor which samsung’s should beat with similar light quality and better output.
SST-20 95CRI are still great leds that thanks to its high R9 do not have real competitors yet.
Look like lh351c have the same phosphor dice size as lh351b, but dome is same size as lh351d.
Just to reference here is a photo of LH351C next to SST-20 and XP-L HI.
Hotspot is quite big next to two others.
I can not see how these can be effectively dedomed, it looks like the phosfor is mixed with silicon, just like many other leds (i.e. all Nichia’s), so there is not a transition to a different material between silicon and phosfor area that has a weak adherence, like in the classic Cree’s.
But these can be sliced very effectively, if you are very good at it you can slice it up to a tiny bit into the phosfor layer, leaving a matt surface, just like a dedomed Cree, and I suspect with the same quality of photon recycling.
link to djozz tests
Thanks sungar.
I haven’t sliced any led yet, so no doubt I’m not good at this… I’m also a bit afraid that lumen output will drop to the level that there will not be any significant increase in throw.
Anyway, djozz whats your best way to do it?
Here are some beamshots (4500k locked) under quad LEDiL ANGIE-S optics:
XP-L HI V4 3A:
SST-20 J5 FB4:
LH351C GE4RTMF:
Surprisingly in the camera Cree leds were much greener than Samsung leds. My eyes however saw this other way around. XP-Ls are colder, more blue ones. LH351C looks more like pure 5000k, but wilt slight too much green in it. Everything else then a white ceiling look better under Samsungs. In my opinion Crees have tendency to overexposure green in colorful scenes.
Where did you find the XP-L HI V4 3A? Though your pic shows a greenish tint more similar to 3C.
Hank had this listed as an option for 4XP 33MM MCPCB:
On one hand you might be right this is 3C as I don’t see 3A XP-Ls available as bare led.
On the other it look more like 5200k-5300k than 4900k to the eyes. On camera it look totally different.
Hi Agro, what is that calculation method you used to estimate the actual die size? It seems like the magnification would depend on the refractive indeed and geometry of the dome.
By the way when I measure the apparent die size, just estimating with calipers, I get something closer to 3mm wide. Not sure if some difference in perspective, like using a macro lens or something, could cause some difference in apparent die size in maukka’s image. The large apparent die size is supported by the large beam size in my picture here. Hotspot size is very similar to sliced XHP50.2.
I assumed a hemispherical dome and formula from here.
1.5 refraction index = 1.5x magnification.
I averaged edge lengths because the photo is not straight from above.