MOD: Making the 15,000 lumen rating a bit more honest. (RHD-BUCK-18A2CH-V02)

Grabbed one of these a few months back (though from a different source):
Trustfire 15000lm 12x CREE XM-L T6 LED Flashlight - US$86.00



Notwithstanding the 15,000 lumen rating, in reality, each of the 12x CREE XML LEDs was only seeing about 500mA with the stock driver, which made their lumen estimation absurdly preposterous, and meant that the LEDs were at least 6x under-driven.

I decided that they needed to be run at their full(er) potential of 3A each, so I decided to adapt my buck platform to make an 18A (2x 9A channel) buck driver.


Custom 18A (via 2x 9A channels) buck driver, specifically for this light .

And yes, it can pop balloons


http://youtu.be/dBmNThmvJeA

Does that driver have any modes? i always thought it would be amazing running one of those flashlights to their max,
Does is heat up really quick too?

RYDorDIE278 said:

Does that driver have any modes? i always thought it would be amazing running one of those flashlights to their max,
Does is heat up really quick too?

Click to expand...

It has two, on and off

I don't like modes on large lights that are only meant for brightness. If I want a dim flashlight, I'll use a small single cell light. It's not like this 18650 needs to be appropriate for every day carry

It gets pretty hot, pretty fast, though there is a fair amount of metal in this guy for heat sinking.

RHD, the photo of that driver, is that one you made, or one from the flashlight? I am asking because I could use a 2 X 9 amp buck myself.

Laser Project said:

RHD, the photo of that driver, is that one you made, or one from the flashlight? I am asking because I could use a 2 X 9 amp buck myself.

Click to expand...

It's the one I made.

I bought a couple of these trying to do with two paralleled together what you made in one. My thought was to put voltage dropping diodes in series with the output to get it close to the voltage I wanted. Since it turns on at 10 percent (20% for two in parallel), I was thinking a soft start might not be so necessary, if it doesn't have it. I'm still waiting for them.

Constant Current LED Circuit Board Driver 3 Modes 5 5 15V 9A SST90 Flashlight | eBay

Laser Project said:

I bought a couple of these trying to do with two paralleled together what you made in one. My thought was to put voltage dropping diodes in series with the output to get it close to the voltage I wanted. Since it turns on at 10 percent (20% for two in parallel), I was thinking a soft start might not be so necessary, if it doesn't have it. I'm still waiting for them.

Constant Current LED Circuit Board Driver 3 Modes 5 5 15V 9A SST90 Flashlight | eBay

Click to expand...

If this is for driving an IR diode bar, then I think you'll run into a couple problems.

For one, the frequency of the switching controller on this probably isn't terribly high. Maybe 200 khz ish range. Couple that with the fact that the inductor isn't huge for something capable of 9A, and my bet is that the inductance is low also. Low inductance + low switching frequency = larger spikes. IRs are sensitive. I think you'll risk killing them with that driver.

Anyway though, good luck! Consider adding some caps. Cheers

Thanks for the heads up, I will scope it out, it's for a C-Mount 808nm diode 400um. What if I put a Lasorb or some other device to clamp the spikes? How far above 200 KHz is better suited? I'm wondering if thicker wires for the inductor might help with the current, replacing it with another of the same inductive value but lower resistance.