Samsung LH351D 5000k LED output test by Texas_Ace - Amazing output, low thermal resistance but high Vf

Yeah, it will limit the current to make the light more useful but on the flip side if you already have a regulated driver it will drop out of regulation much faster then other LED’s.

For example I generally use the TA drivers with the all 7135 mode but it is nice to have the turbo mode for when you want some extra.

Sad to hear that the high CRI versions could be green, I have had enough green LED’s for my lifetime.

Wow! 1000lm - 137lm/w (XP-G3 - 100lm/w). Way be very usefull for small capacity lights.
LEDs from same reel were tested by maukka: Samsung LH351D color testing

Yeah, these blow the G3 out of the water. The tint is much better then the G3 or L2 as well, no ugly tint shift that I saw.

Good to see that they also have good tested tint as well.

These samsungs are not using the flip chip setup, which in part explains the higher Vf. It could also mean they can be dedomed, although I have never really liked or been very good at dedoming.

Looks like an XP-L(2) sized die. So it’s no suprise that it’s brighter and more efficient than smaller LEDs like the XP-G3.

Sure, but cost-wise the LH351D is a competitor to the XP-G3 instead of XP-L2.

Nice test, TA. It looks like DigiKey has these at a pretty decent price and with good price breaks, too.

I’m wondering… would you be able to do a combination chart with this vs the XP-L V5 data you have? Looks like a real close competitor and a graph might help.

Also, what (if any) reflectors have you tried this in? How’s it look (especially with regards to tint-shift)? Maukka mentioned it looked good in his initial findings, then said it looked ugly when put in an EE X7.

Not necessarily, that is only for buck drivers with the same amount of input cell stages as in series output emitter stages. Besides all the theorizing, this for example is no problem with 2+S input for a single emitter, the down-side of this approach may be finding good 18350/26350/whatever short cells, formats which are not developed/manufactured by the big players in the li-ion industry.

This is the reason many times I've wished for a buck/boost driver which, on the other hand, would be necessary for driving violet/UV based emitters properly, I believe.

Cheers :-)

Is there still nobody who sliced it and can estimate die size? Or throw?

I almost did but didn’t :stuck_out_tongue:

But looking at the domed led the die size is at least very close to XP-L/XM-L if not exactly the same.

what is latest thread on these samsung?

Stupid question here: are these led “good” to be used with the MTN DD drivers in triples or quads?

Since I started using the Wuben TO50R with these Leds, much has changed in my perception of neutral white and high CRI, so I wanted to build another light with these. But I want it to be triple or quad, floody!

Thanks in advance for the answers!

These LED’s seem to be better suited to reflectors vs TIR optics in my experience. I think that the large die is just bigger then most TIR optics are designed for.

In reflectors they actually look pretty good.

I recently built a few AAA lights with some of these that a member on here sent me for my family members “purse lights” and they look really good in those.

Not a big fan of them in my S42 though.

That said, if you’re pleased with how they look in the TO50R optic and you can find a suitable optic for your build, I doubt you’d have any issue with a triple/quad and a FET driver. Between these having a higher vF and you running multiple (presumably in parallel), I don’t foresee any problems.

Yes, they will work just fine, only the beam quality is in question.

I like these in reflector lights, because of the big die the beam looks nicer and is easier to center and focus than small-die leds, i.e. the White Flat is quite a pain to center and focus.

TA, gchart and djozz, thank you very much for your input on my questions!
I didn’t realize these leds are larger than the other “typical” LEDs! :zipper_mouth_face:
Still, I guess I can mod an optic to make them fit :smiley: Or…maybe I can use them just in reflectors!

BTW, I know that OP reflectors are probably better for these, but do they “perform” well with SMO reflectors? My Tool AA lights could benefit from an improvement if they are good for SMO as well.

Once again, thank you very very much for the replies :wink:

They will fit most optics designed for 3535 LED’s just fine. It is the die itself that is larger, basically the actual light emitting surface.

This can cause issues with the light entering the optic from an angle it was not designed for and this can lead to odd beam patterns.

Psychically they should work fine though.

Yes, in small reflectors like that they work well in SMO or OP reflectors in my experience.

Ahh, sorry! I understood it wrongly. My brain processed “dome” instead of die! Ok, so if they fit will, I guess I won’t have problems with that! Also, I will probably use some optics such as 10511 or 10508 (floodier) so it will be a “wall of light” per se!

Thanks for the clarification!

And also for the info on the small SMO reflectors ! I may have a winner then :wink: I do like the Luxeon Leds, but after seeing what these do…I definitely wanna try them in other lights :wink:

Thanks once again for the information!! :beer:

Yup, I’ve put LH351D’s in a few Tool AAs with great results. They make a nice combination.

The last emitter swap I did was in a tool ti AAA. Turned out pretty good. I then swapped one in the brass tool AAA and shaved the LH351D.
I liked the shaved version better, actually I haven’t found anything yet that shaving this led didn’t look better in. I also built a triple in a RRT-01 and used the KD triple optic with shaved LH351D’s, turned out very nice. Wasn’t as nice with a carclo, too floody and the KD optic seemed to make the tint more pleasent.