Future development of the maximum luminance of LEDs

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Enderman
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djozz wrote:


At 5A discharge, the Aspire 18350 (HKJ’s chart below is from the Vapcell version) starts at 3.7 V, going down from there during drainage of the battery. Assuming that the tailspring in your flashlight build is not bypassed, at 5A the spring alone will already cause more than 0.2 V voltage drop, the last 0.1 V will surely be lost elsewhere in the current path.


 



It looks like it starts at 3.7, but at the beginning it is close to 4.2 like all other batteries.
The surge current happens when the circuit is first closed, and this initial spike in current is what will blow an LED in the first few milliseconds.
Jerommel
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This could be due to smoothing of the graph though, i was told the drop is instantly when i asked about the same phenomenon.
A large enough capacitor over the driver input could solve such problems though.

Enderman
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True, or an in-line inductor.

Jerommel
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Hey, you said you saw a test of this “Flat White” TG somewhere.
Do you have a link?
Wondering if it’s useful to run it over 4 Amperes.

Enderman
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Jerommel wrote:
Hey, you said you saw a test of this “Flat White” TG somewhere.
Do you have a link?
Wondering if it’s useful to run it over 4 Amperes.

Depends on cooling.
The Driver had his black flat running at 4.5A in his xcalibur, and he had some graph showing how the output drops to 75% after a few seconds or minutes.
I got output increases to about 6 amps on my black flat because I was cooling it with a fan cooled CPU heatsink and liquid metal.
The CSLNM1.TG is basically just a better black flat as far as we know, so I would assume it can also do 6A or even more with appropriate cooling.
luminarium iaculator
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From 3.3A to 6A it has performance variation of cca 30%. Above 6A it starts to drop in simple aluminum flashlight host.

So logically with better cooling it gotta perform better.

I did not get cherry picked Osram White emitters either. So 10 % lux variations are possible like with any other emitter.

Enderman
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luminarium iaculator wrote:
From 3.3A to 6A it has performance variation of cca 30%. Above 6A it starts to drop in simple aluminum flashlight host.

So logically with better cooling it gotta perform better.

I did not get cherry picked Osram White emitters either. So 10 % lux variations are possible like with any other emitter.


I’m going to buy a DPS5020 immediately so that I can actually test the LED at high currents Smile
We’ll see how hard we can push it.
luminarium iaculator
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That would be nice… Beer

The_Driver
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Enderman wrote:
Jerommel wrote:
Hey, you said you saw a test of this “Flat White” TG somewhere. Do you have a link? Wondering if it’s useful to run it over 4 Amperes.
Depends on cooling. The Driver had his black flat running at 4.5A in his xcalibur, and he had some graph showing how the output drops to 75% after a few seconds or minutes. I got output increases to about 6 amps on my black flat because I was cooling it with a fan cooled CPU heatsink and liquid metal. The CSLNM1.TG is basically just a better black flat as far as we know, so I would assume it can also do 6A or even more with appropriate cooling.

I would never go to 6A with passive cooling. The center of my Black Flat has started to slowly turn black at 4.5A!

Hoop
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A soft start turbo would pull the cell voltage down before going 100% fet.

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Say I would like to solder a coil inline with the one of the ledwires to dampen the surge voltage, what value would do the job?, would a coil recovered from an old buck or boost driver come near what is needed? Same for a cap across the ledwires, what value would work?

LichtAn
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Also posting this here, so it may reach more people that are interested.

I just put the new OBF successor in my BLF GT Mini. The max I measured was 282k cd. But with a protected battery at 4.1V the current is already at 6A at the tailcap. I’ll see if I modify the firmware to reduce the max output to 80% PWM. But the LED scaled all the way up to 100%, so I’m wondering what the actual limit is.

Even at 3.65V battery resting voltage, I get 260k cd. So it was probably overdriven a lot.

Beam looks like this. Ideally the 2 rays limiting the hotspot should be parallel right?

luminarium iaculator
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Nice… But please add which battery did you used…

This emitter is like Viagra it doesn’t fall in performance Smile It will perform with 6A and 3.3A Wink

LichtAn
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luminarium iaculator wrote:
Nice… But please add which battery did you used…

This emitter is like Viagra it doesn’t fall in performance Smile It will perform with 6A and 3.3A Wink

Keeppower 3500. So a protected GA

luminarium iaculator
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LichtAn wrote:
luminarium iaculator wrote:
Nice… But please add which battery did you used…

This emitter is like Viagra it doesn’t fall in performance Smile It will perform with 6A and 3.3A Wink

Keeppower 3500. So a protected GA

Did you used spring bypasses?

LichtAn
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luminarium iaculator wrote:
LichtAn wrote:
luminarium iaculator wrote:
Nice… But please add which battery did you used…

This emitter is like Viagra it doesn’t fall in performance Smile It will perform with 6A and 3.3A Wink

Keeppower 3500. So a protected GA

Did you used spring bypasses?

No stock GT Mini. Double spring in the tail and single driver spring. With bypasses and low RI cell I can easily see this pull 8A at least. Cool Boom!

luminarium iaculator
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I guess that Panasonic GA is ok if it will not pass 6A mark in DD setup where this emitter starts to loose performance…

I tried this low current cell: LG 18650 BD1 (pink cell unprotected) and since that is 4.35V cell charged to 4.2V it did not passed 5.5A with Osram white so I guess if charged to 4.35V it would not pass 5.8-6A but I don’t have 4.35 charger to test that.

Edit: Linear driver should be better choice.

luminarium iaculator
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BTW BOOM! Will not happen at 7.2A… Tested with Samsung inr 30Q(real Samsung cell from nkon.nl) … And I really doubt GA can reach 7A mark even with bypasses. Let me check… Yes in my test performance at 7.2A performance drops for cca 20%

LichtAn
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I got a VTC5D sitting here. Crazy Nah I’m not gonna blow the LED up. I really love the light!

luminarium iaculator
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Oh yes I forgot that there are better high current cells than Samsung 30Q that could actually reach 8A… Well I would try but I don’t have better than 30Q. If you ordered couple of them than why not? Beer

Maybe you got lemon among lot and better emitter awaits to be build… You never know…

LichtAn
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luminarium iaculator wrote:
Oh yes I forgot that there are better high current cells than Samsung 30Q that could actually reach 8A… Well I would try but I don’t have better than 30Q. If you ordered couple of them than why not? Beer

Maybe you got lemon among lot and better emitter awaits to be build… You never know…

Well the reflow annoyed me more than it should and centering the reflector took me an hour. Sad
Usually destroying is my thing, but not YET here. Innocent

luminarium iaculator
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Perfect reflector centering is PITA. I got best performance when I tossed centering rings and just used eyes and lux meter for centering… That why I prefer zoomies or aspherics.

So“only” 286kcd in that GT mini? Mitkos super budget 10$ thrower(aka supwildfire something) flashlight simply destroys that performance at 430 kcd but yes… Some guys will say pencil beam Smile

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In my tests the GT mini reflector is not good for these 1mm2 size leds. Emisar D1S is much better.
See here.

The_Driver
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Can you guys maybe discuss specific lights in a new/different thread? This thread is more about fundamental changes to the LEDs themselves.

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This new “flat black” is very interesting.

Will it be available in NW tints at any point? I assume the ones on LED4power are CW?

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I just tried them. In the GT mini I got 219 kcd with it but it need to raise the reflector a bit. Tonight I have no time for that. And putted one in a 9×7135 convoy driver convoy S8. The reflector is a regular S2+ Smo reflector. It has fix 3,15A current and I got 30800 cd. Not bad from a tube light Smile
With dedomed XP-G2 this same light made 22000cd.

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Impressive numbers, if this LED is available in NW I can think of a lot of uses for it.

I just can’t bring myself to dig into a CW only LED since I know I will never truly like it. lol

The performance numbers sound real good though!

luminarium iaculator
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ZozzV6 wrote:
With dedomed XP-G2 this same light made 22000cd.

In my test at 3.3A it had same performance as the best G2 (xpg2s42b dedomed) on 4.7A current draw. So comparing to other and older classic dedomed G2 emitters it should over perform them even at 3A as you said.

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If somebody want to see some pics of the led and some beamshots there it is.

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Texas_Ace wrote:
This new “flat black” is very interesting.

Will it be available in NW tints at any point? I assume the ones on LED4power are CW?

Using the kw cslnm1.tg spec sheet.
The chromacity bin is: ebxD46. Looking at the Osram datasheet and plugging the coordinates into this website,
https://www.waveformlighting.com/tech/calculate-color-temperature-cct-fr...
the CCT is between: 5849k to 6384k.
Less cool than the Black Flat. The warmest tint bin in this series is the fcbB46 that range from 5,3xx to 5,8xx. However, I have the Skylumen Delta with the Black Flat 6500k and the tint is actually very white with no blue and being a WW/NW fan, I find this specific 6500k very acceptable even though I dislike other bluish 6500k lights I’ve seen. Maybe it’s because of the negative DUV makes it appear whiter?

Plugging the coordinates here:
https://www.waveformlighting.com/tech/calculate-duv-from-cie-1931-xy-coo...
the DUV is between: -0.0044 and -0.0043, which will at least ensure the beam will not be green, maybe it will be a bit on the rosy side. I like the pure white of the black flat. Hopefully this is about the same.

The flux bin is 6N
at 1A: min 315 lm and max 355 lm

Compared to the Black Flat sold on Mouser, which is 8M flux bin:
at 1A: min 250 lm and max 280 lm

Djozz tested the LED4Power at 6100k. There’s a bunch of other good info in this thread.

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