Can anyone tell me if the XM-L is a “standard” led, I have a few torches that are supposed to be XM-L, but with a fair bit of variation in output, or is it all down to the driver.
All down to the driver, reflector and bin/tint of the particular XM-L. The XM-L is a ‘standard’ LED, but it’s available in different brightness and color bins. The driver and the reflector have far more of an effect on brightness than the tint/bin of the LED though.
PPtk
It’s just like a car, it’ll go faster if you give it more gas. Some lights only driver the light at 1.5 amps, versus some at 3.0 amps. That’s a difference of several hundred lumens going from 1.5 amps to 3.0 amps. And like pilotPTK said, the bin is a part. A U2 binned xml will produce more lumens than a t6 binned xml, because the U2 is more efficient. And you might get 800 lumens at the led, but once the light travels through the reflector and lens, you might get only 80% of that.
Not sure, but hope this helps. I think people check the LED code with this: www.cree.com/products/pdf/xlampxm-l.pdf or do lumen test off ceiling bounce. Maybe they are xm-l T5 instead of T6.
hope it helps. I’m still learning.
There is no way that anyone will be able to detect the difference between a T5 and a T6 just by using the Ceiling Bounce test. Not a chance.
Tnx for that guys, so what is the approx max ampage an XL-M would take before it fries??
It all depends on the heatsink really. On regular aluminum ones, you can still run 4 amps, but only for a few minutes before you get heat sag and stuff. But there’s a guy who put an xml straight onto a copper heatsink and he did like 4.5 amps. Here it is He did over 6amps and after 5 minutes on that, the led only dropped 1367 to 1357 lumens. He could’ve ran it at higher amps, but that’s the highest his source would go. I’m sure you could take it to 9 amps.
The biggest enemy of leds, and just electronics in general is heat. Ever see those world records where people get some dry ice or liquid nitrogen to cool down the cpu, and overclock insanely?
Most higher powered xml’s are driver at around 3 amps for around 850 lumens. But like alot of things, you get what you pay for in flashlights. The more expensive lights have better quality control, better electronics, better features, and more mass. The mass, usually in the form of aluminum, and sometimes copper, draws the heat away from the led. So that it can stay at the same brightness without heat sag. Some higher powered lights even have small fans blowing over the heatsink! Someone on this forum is making a 18 or so xpg light that utilizes a 20 pound cylinder of copper.