Cree XM-L2 and Driver source

Charon

Newly Enlightened
Joined
Feb 25, 2008
Messages
78
Location
Okanagan, British Columbia, Canada
I have been out of buying LED's and parts for a while so don't have a clue where to source these from anymore. Any reputable suppliers selling a Cree XM-L2 and a really good driver board? I have a flashlight I no longer use with my bunker gear because I picked up a Fox Fury BT3

http://www.foxfury.com/catalog/rechargeable-breakthrough-bt3-led-right-angle-light-black

But its only 600 lm for its size which is larger than I would like.

If I could upgrade my streamlight survivor to a Cree with 1000+ lumens it would be brighter and significantly more useful than the box lights we carry on our trucks.
http://www.streamlight.com/product/product.aspx?pid=88

Anyone know if the driver in the streamlight would support the Cree XM-L2? And/or how to figure out its est output if the existing board would run it, or a recommended driver board and I can gut the streamlight and put the new driver in.

The streamlight uses 4xAA 6V.

Have to get my head back into the numbers on this.
 

Mr. Tone

Flashlight Enthusiast
Joined
Jul 2, 2009
Messages
2,350
Location
Illinois
You could swap it without a new driver but wouldn't gain much. Mountain Electronics is a great source for drivers and LEDs.
 

DIWdiver

Flashlight Enthusiast
Joined
Jan 27, 2010
Messages
2,725
Location
Connecticut, USA
The driver in any decent light should be a constant current regulator. The light output of an LED is roughly proportional to current. I'm going to take a little liberty with the truth and convention and say that a good modern single-die LED should get around 200-400 lumens per amp. The actual number depends on many factors, including the choice of LED, color temperature, CRI, etc. The state of the art is ever approaching the theoretical limit, which is something in the vicinity of 900 lm/amp

If you just swapped out the LED, the current wouldn't change much, if at all. If you swapped a 250 lm/A emitter for a 300 lm/A one, you would see a 20% increase in output. If you swapped a 200 lm/A emitter for a 400 lm/A one, you would see a 100% increase in output. It would be really optimistic to think that you could achieve this, but it's not inconceivable.

Another thing to think about is the die (emitter) size. Given a specific lens or reflector, if you increase the emitter size, the beam will get wider. If you replace a smaller emitter like an XP-G with a larger one like an XM-L2, you will probably get more lumens, but because these are spread across a larger beam, it may actually be less bright.

To get lots more light out, you really want to increase the current. This means more power, which means shorter runtimes and more heat. Since the light looks to be in a plastic housing, heat might be the original limiting factor. If it is, then any attempt to coax substantially more light out of this thing will be an exercise fraught with problems.

That said, it is possible on many drivers to increase the output current simply by changing one component. This will often increase the stress on the driver, adversely affecting reliability and lifetime, but not always.

You may also be able to replace the driver with one designed for a higher current.
 
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