This is a new LED and still uncommon. There is not much of information available, other than the data sheet. It is just nice to see them installed in the lights.
It’s not really a thrower LED. It has larger die area than SBT90.2 and produces far less output. I think Clemence has tested that but I can’t find the results now.
Anyway E21A is not a thrower LED and this one will only throw less. But when high CRI is a requirement, there are very few choices - and this is a fair one.
ADDED:
The high CRI variant does not much more than 2000 lm at the peak. So intensity is ~3 times lower than that of Boost HX.
I used to think that “3 times lower” means y = x / 3 but “lower by 3 times” means y = x - 3 * x = 2 * x. That is the first term is multiplicative and the other additive. That’s how it works in my native language. I read your message as “3 times lower” means y = x - 3 * x = –2 * x in English. Have I used it wrong for all these years? I see you’re from the USA, so I assume you’re either native or advanced Engligh user. Is there a multiplicative term in English?
Just came here to point out a slight incorrection in the above test graph:
Where it says “max. recommended current” for the NV4WB35AM the value (2.5A) is wrong. I am right now peeking at the NV4WB35AMT (NICHIA STS-DA1 5768D <Cat.No.201223>) datasheet and in Absolute Maximum Ratings it says forward current 1800mA and pulse forward current 2400mA.
It’s not wrong. It’s just a different recommendation.
Nichia’s specification is based on whatever their criteria are for ensuring longevity of the LED.
Clemence’s recommendation is based on his own experience, but also assumes very good thermals. My understanding is the Noctigon DM11 actually drives the B35AM at 3.6A, which is significantly higher, and I haven’t heard anyone complaining about killing them yet. On the other hand, I think Convoy tried running the B35AM at 3A, presumably on a more conventional MCPCB than Clemence makes, and was having issues with it smoking.
Also, we should assume we will get shortly LED life than specified when running at higher than the manufacturer recommended currents. But it is hard to accrue thousands of hours of use at maximum power with a flashlight.
Yes I understand the “longevity criteria”, and I was not expecting to see any other “max. recommended current” than the one in the datasheet.
The DM11 looks pretty, I would love to know what kind of optic it uses. Looks like some sort of narrow angle TIR, doesn't it?
The rated intensity for the B35AM seems a tad low vs the usual low-CRI throwers. Is the die size so big?
Yes, I wouldn't be surprised if Convoy wasted some B35AM emitters. They also have taken other not so good decisions in the past, like deciding to drive the W2 4040 CULPM1.TG at up to 8A (can't see the driver @ Convoy store due to fake pandemic measures) when the CSLPM1.TG maxed out at ≈7.6A in Djozz test (it's overcooked, imho). Hope they get better as soon as possible.
Nice to know about the quality of Clemence's boards for the B35Ax. :-)
You can’t compare 16mm B35 MCPCB from Convoy with 32mm B35 MCPCB from Noctigon in the first place for non-DTP LEDs, also who knows what trace thickness (Oz) Convoy uses, can’t be as high s Noctigon board use in general. Then there is dielectric material quality also for non-DTP LEDs.
Yes the board’s performance is important, we can probably assume that nichia rates it for use with common MCPCB.
We don’t have a direct comparison between Convoy boards and Eurekatronix boards but take a look at this comparison between DTP (orange), unknown non DTP (blue) and non DTP Eurekatronix (grey) with 3535 leds.
Pathetic performance from unknown non DTP, Eurekatronix non DTP is nearly as good as DTP.
Interesting graph, thanks for sharing (source?). What led emitter was being tested in it?
Since this led emitter (NV4WB35Ax) is two terminal, I guess there is no way to DTP it without connecting either the positive or the negative terminal to “ground” or the flashlight body in a flashlight. This also matters when attaching multiple boards in series to a heatsink…