Nichia NV4WB35AM

Agro · 2021-04-28T20:16:18.000Z

I haven’t ordered yet. I don’t have the right conditions to do any modding nowadays and my excitement has faded.

Dalamar · 2021-04-29T16:50:52.000Z

Is this my long awaited high CRI thrower? Right after I order GT94?

I want one in a triple-sized 21700 C8 with parallel batteries.

Agro · 2021-05-01T09:23:15.000Z

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.

lumenzilla · 2021-07-15T09:43:47.000Z

I got mine from Clemence (Sm505 E1200 R70) but haven’t got any chance to test it yet.

elendur · 2021-10-31T19:12:04.000Z

Agro:

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.
[picture]
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.

3 times lower intensity than Boost HX… does that generally mean 3 times lower candela once place inside a reflector?

Agro · 2021-11-01T06:43:55.000Z

elendur:

Agro:

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.
[picture]
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.

3 times lower intensity than Boost HX… does that generally mean 3 times lower candela once place inside a reflector?

Generally yes.

iamlucky13 · 2021-11-02T00:54:12.000Z

elendur:

Agro:

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.
[picture]
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.

3 times lower intensity than Boost HX… does that generally mean 3 times lower candela once place inside a reflector?

Math nitpick warning:

Technically that should be 2/3 lower (1/3 the original value).

3 times lower would imply negative light.

Agro · 2021-11-02T06:38:32.000Z

iamlucky13:

elendur:

Agro:

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.
[picture]
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.

3 times lower intensity than Boost HX… does that generally mean 3 times lower candela once place inside a reflector?

Math nitpick warning:

Technically that should be 2/3 lower (1/3 the original value).

3 times lower would imply negative light.

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?

iamlucky13 · 2021-11-05T03:23:59.000Z

Agro:

iamlucky13:

elendur:

Agro:

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.
[picture]
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.

3 times lower intensity than Boost HX… does that generally mean 3 times lower candela once place inside a reflector?

Math nitpick warning:

Technically that should be 2/3 lower (1/3 the original value).

3 times lower would imply negative light.

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?

The literal meaning in English is y = x - 3*x = –2*x.

However, most people in the US mean x/3 when they say 3 times lower.

Agro · 2021-11-05T03:40:26.000Z

I see, thx

Barkuti · 2022-01-01T22:31:46.000Z

Agro:

…

ADDED:

…

Weirdest output graphs ever seen! Are you sure this is correct? Oh! There's a change of scale at 1A and upwards on the x-axis.

These look very well suited to be driven with a 3A “6V XHP50” driver.

Clemence is only listing 4S or 12V versions in his website, this is less desirable from a flashlight point of view; at least if one is looking for a compact ∅20mm 12V boost driver. :-/

P.S.: considering that it is a very high colour rendering led, I'd say it can be considered thrower in its class.

Barkuti · 2022-03-19T01:10:55.000Z

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.

iamlucky13 · 2022-03-19T01:42:19.000Z

Barkuti:

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.

Barkuti · 2022-03-19T05:04:15.000Z

iamlucky13:

…

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.
…

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. :-)

Hikelite · 2022-03-19T08:59:13.000Z

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.

thefreeman · 2022-03-19T10:54:05.000Z

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.

Barkuti · 2022-03-19T12:02:34.000Z

thefreeman:

…

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…

thefreeman · 2022-03-19T12:20:16.000Z

Clemence did the tests to see if he could salvage those 3535 MCPCB that the factory botched (they forgot to DTP the center pad), he tested with a hole drilled into the copper and dielectric to DTP it, as well as a slot, but the slot is still not as big as a normal center pad, that’s probably why it doesn’t fully reach the DTP MCPCB performance. I have just received some of those MCPCBs and will make a large slot for DTP.

DTP the cathode is possible with a driver with high side current sensing topology, I have one project where I am doing this.

Barkuti · 2022-03-19T12:43:53.000Z

Don't really know about that story you are speaking off, except that it involves some ER16S1-35-DTP boards.

Yes, the usual low side sensing in drivers combined with negative ground bodies is one of these inconvenient things I've always wondered about. I guess high side sensing is a solution for all cases, and this would open the market for much easier adoption of two terminal leds. The performance of non-DTP Virence boards is already praiseworthy, though.

BlueSwordM · 2022-03-19T14:27:09.000Z

Man, I wish we could help Convoy regarding MCPCBs.

The problem is that he’ll have to make his own custom PCB to get low thermal resistance out of it.