XML 9T6 "11000Lumen"

With correct thermal measures its possible to operate an CREE XML at 5A [copper MCPCB, Peltier, etc]. But... the relative luminous flux seems to go flat past 3.5A, with almost no appreciable gain in output past 3.5A.

Why use LDOs with LM317 or LM358 though? There's a ton of constant current buck regulators out there more contextually appropriate to drive LEDs of this caliber.

I'm running a copper base t6 direct drive (not even a resistor) off an 18650 in an aurora c6 host, which is tiny. It heats up pretty quickly but man its a beast, its pure flood but there is so much light it still gets some distance.

I have no idea of how much current its taking but it eats through a 2000mah 18650 in 30 mins or so. So I'll guess 4-5 amps. So if you have good heatsinking I think you could feed them a good 5 amps

I've got a 12x XML light that I'm planning to mod into a proper (or improper, depending on perspective) 3A to each LED flashlight.

In my case, I'm going to parallel 3x LEDs, put that in series with another 3x LEDs in parallel, and then repeat this in two channels. Then I'm going to use a buck driver with 2 channels of 9 Amp output, powered by 6x Panasonic high drain 18650s (3 parallel, in series with another 3 parallel).

Illuminum3415 said:

With correct thermal measures its possible to operate an CREE XML at 5A [copper MCPCB, Peltier, etc]. But... the relative luminous flux seems to go flat past 3.5A, with almost no appreciable gain in output past 3.5A.

Click to expand...

Not true...

XM-L2 Leds will increase in brightness right up until ~8 amps. It may be quite inefficient running
an xml2 passed 5 amps but that does not mean there is no gain in lumens.

This is only possible with the xml2 on a DTP (direct thermal path) copper MCPCB.


(Thanks djozz)

@rhd, this \/\/ thread on blf is a good read, it's a flashlight build very similar to the one that you're suggesting

Mod: <15000 LUMEN of NW tint mixed light and 200+ kcd

Lol, not only is that a similar build, but it's the exact same host!

Can't figure out why I'd want to go FET though. Switching seems more appropriate.

rhd said:

Lol, not only is that a similar build, but it's the exact same host!

Can't figure out why I'd want to go FET though. Switching seems more appropriate.

Click to expand...

I figured as much reading the battery configuration that you had in mind instantly made me think of that host.