building an air rifle light, best color temp and 1 mode board?

[lupy]

I am working on modifying a light to mount on my Theoben Rapid7 air rifle. There is almost no recoil, so I am thinking about starting with a zoom focus light and replacing the emitter and driver board, putting on a momentary switch, and may mount the battery further to the rear for balance. Fasttech sells quite a few different XM-L2 emitters, I am thinking I want a warmer (lower K) emitter to give the best color tones in the woods, and I would also like a one mode driver board. http://www.fasttech.com/products/16...ee-xm-l2-t5-5a2-1100lm-4000-4300k-led-emitter is my initial thought. matched with http://www.fasttech.com/products/16...2745v-4-group-134-mode-1100-ramping-led-drive anyone use one? or maybe two of these http://www.fasttech.com/products/16...4-amc7135-led-flashlight-driver-circuit-gener I know these are linear regs, but it's not for constant use, so I don't think heat will be a problem. Anyway, your thoughts would be helpful.

 

[Rod911]

Emitter choice is fine. Nothing wrong with using an aluminium MCPCB if you aren't driving the LED hard (ie. > 3A).

The first driver you linked (4-group), isn't really a single mode driver. However, the second one looks fine. That is, if you don't mind driving it at 1.4A. You could buy yourself some more AMC7135 chips and stack more chips on top of the existing ones to drive the LED harder. Otherwise, you might want to consider this driver instead if you don't want to do any soldering as that is at 2.8A.

 

[lupy]

As I understand it, the 1st driver has several modes, one of which has a single level. This would be great incase I want to play around with the other modes at some point. THe only down side would be if blipping it momentarily on and off with the membrane switch would accidently get it into mode change. The other problem I see so far is that my current light (501) seems to have some resistance in the wiring such that it won't drive over 2A on a single cell. I might try a slightly stronger Lipo to see if it would overcome the problem, otherwise I may need to look at 2 cell compatible boards, which I believe eliminates the AMC7135 based boards.

 

[Rod911]

Soldering copper braid or heavy gauge wire (at least 18AWG) to the springs at the tailcap helps reduce resistance. Also, your typical Panasonic/LG/Samsung/Sanyo cells don't really have that much of a resistance issue. However, if you really want cells which do not have that much resistance, then getting either the NCR18650PD/PF, Sony VTC64 or Samsung 20R should be considered. But IMHO, these type of cells aren't warranted unless you're driving a light at > 3.5A.