Of course its not regulated. If DX sells ANY li-ion lights that are properly flat current regulated through the ENTIRE operating voltage range of the battery via the diver, I am not aware of them. Some do to a certain degree, but I don't recall one that maintains that current from start and until the battery is depleted (3.2 - 3.5V). In most cases, or to a greater degree, the stability of a descent battery somewhat provides this service - not the cheap driver. Depending on the resistance and forward voltage requirements of the particular xm-l sample I receive will determine if the stock driver in my light will be appropriate. I suspect it will but, and I will test it at the connecting lead to the star with a DMM just to be sure its within spec. Up to .5A over will not be a cause for alarm unless I read or discover otherwise. What are your thoughts? Have you found any drivers that might regulate well @3.0A from 4.2 down to 3.2V? Anyone? (something without hords of 7135's please)
As an aside, the lumens on the preliminary spec sheet aren't as great as many had anticipated. Still, I suspect it will be a very noticeable leap above the current MC-E or P7 offerings when driven at the same levels, at least to the naked eye. Along with that, the large footprint of the LED to the mounting surface should transmit heat quite well, and hopefully allow for a certain amount of current above the published max... we can only hope! This is exciting and it can only get better as newer and more efficient bins are introduced. The true test if these produce bright light without artifacts; would be for gynocologists that currently hail their remote xenon short arc light sources for shedding light upon their subjects, to make the change to XM-L. I guess I better find a forum where members boast about their new speculums to see if anyone is interested in the XM-L.
Historically, cutter charges a slight premium for their product, but at least you have access to lesser available bins on the star size you want. And probably more important is the fact that you know what you are getting when you order... unlike the bin lottery you play with Chinese lights manufacturers, including the more expensive varieties.
I'm not so sure. The figures from the dx forum seem to imply that it's regulated to some extent, or otherwise the draws reported wouldn't all be around 3. Witness the recent tr-801 thread where people got everything from 0.6 to 1.9A draws. :) "Regulated" is a tricky word. A lot of these cheap lights aren't flat regulated (and really, it hardly matters), just enough so that it won't fry the emitter with a new battery, and it won't drop too low with a discharging one.
If it's not regulated, the XM-L would likely fail, as I'm guessing the Vf might be lower than mc'e with the typical process improvements, or at least not exactly the same unless you get lucky.
This is supposed the ~2.5A driver at dx that actually works http://www.dealextreme.com/details.dx/sku.20330
I ordered one yesterday. I don't have any light that would need or could even handle that kind of curent, but I figured it's the cheapest source of 7135s available. Remove the chips on the bottom and you're left with a 1.4A NANJ AK-47, plus four 7135s .
I'm a lot more interested in a new LED than I will ever be in a new bin. It may have its drawbacks, but until you get the light in your hands, who's to know?
No idea , but I have been using this driver for almost 2 years now , very versatile , Ive used it on everything , Cree XR-E , Diamond Dragons , SSC P4 , Luxeon K2 TFFC , XP-E , XP-G , MC-E , SSC P7 ..