Re: XPG R5 Maglite Solitaire 10280 Li-ion
You are welcome, but the soli. tail cap has a hole of ~6mm ID,
how are you going to fit a AMC7135
Well, the 7135s on my 1.4A boards (which is where I'd swipe one from) are SOT-89; they're entirely contained in a 4.5 x 4.1 x 1.5 mm bounding box, so it should actually be possible to pot a bare chip with wires soldered on in the 6mm hole. More likely, though, I'll enlarge the hole somewhat, cut out the section of PCB it's mounted on (taking care regarding what traces run clear to the cut edges), bulk up the connecting trace with solder, and press-fit it in the bare aluminum hole, hopefully establishing a decent mechanical, electrical and thermal connection. If I get the light to where I'm happy with it, I could then pot it for permanence and slightly better thermal connection.
But how would you get positive to the Vdd pin of the chip? You could cut a slot down the length of the body to run a thin wire. If you got lucky, it wouldn't break through the side. But them how would you screw the tailcap on without twisting the wire off? You'd need some kind of disk/wiper system to transfer positive to the chip in the tailcap.
Good point -- I had planned to run fine wire in a groove (and I prefer to think of it as skill, not luck
), but hadn't considered the rotary joint issue.
*rethinks approach*
Hey, if I strip the heatshrink from the + end of a 10440 and load it "backwards", then I should have access to a + nub and a - ring at the tailcap. I admit I don't really like the idea of needing a non-standard (and relatively difficult to charge safely) battery, but it does seem workable.
:green: No, just thought about it, and that leaves the - end at the LED. So I'd have to run the wire the other way.
I'll think about this some more before I start modding...
And if you're wondering
why I want to do it in the tailcap so bad, I had an idea similar to ma_sha1's new 2-stage twistie. I was trying to figure out how to make it regulated when twisted gently, but short to DD when tightened completely. That's looking a little intricate, so the other option I was thinking is to drill and ream a thru hole, make up a little push-button, and rig things such that loose = off, twist tight = on (regulated), and twist closed + push button = turbo (DD). Either of these requires access to the AMC7135's output, to short it to -, so if the AMC7135 isn't in the tailcap, you face the wire-next-to-battery issue all over again.
Now I may not be ambitious enough to implement either of those schemes, at least the first time. I can always pick up another solitaire and do it again with more features, if the first time works; just want to do this one the same way so the lessons learned apply.
Of course, since I'm not using 10280s, and may not even use an XP-G at first (none on hand -- I may cram an XR-E in instead), this is really OT in this thread. I'll start my own thread when I actually start construction.