Future development of the maximum luminance of LEDs

So it should be ok with DD from Aspire 18350. :slight_smile:

Yes, this led in smaller lights can be direct driven.

Hmmm… i think it’s 3.40 Volts at 5 Amperes…
Wouldn’t want to confront it with the full blast of a freshly charged Aspire 18350.

Are you sure?
The VF-current chart looks like it could reach 10+ amps with a fully charged cell.

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.

Under .9V for intl-outdoor springs in Emisar D1. But with thin wires this should be correctable. :+1:
I wonder what’s the IR of Folomov 18650…

Yeah, but with optimized electrical path and a CC FET driver you will have the maximum output for quite a while.
Run it at 4 - 4.5 A and it will be longer with probably not much less output.
Is there a test of this LED on the forum yet?

Didn’t know (or remember) the Aspires sagged that much though.
With cheap springs you can apparently get away with it.

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.

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.

True, or an in-line inductor.

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.

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 :slight_smile:
We’ll see how hard we can push it.

That would be nice… :beer:

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

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

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?

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?

Nice… But please add which battery did you used…

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