Another tiny triple…
I had a bunch of these Luxeon Rebel triples from ledsupply.com for awhile now:
http://www.ledsupply.com/07007-pw740-l.php
These have 3 Rebel emitters, and are configured in series, so normally need >9V at 1 amp.
I’ve previously modded an Ultrafire S5 with one of these triples, using a 1 amp boost driver from CNQ, but I’ve been wanting to build a smaller, 16340-powered light that uses this same triple, so I’ve been looking around for a host.
I finally decided that I’d use a Uniquefire UF-K21 that I bought from FT awhile ago:
[FT also carries a 1-mode version that’s a bit cheaper: https://www.fasttech.com/products/1601/10004109/1358901]
There’re pics of the UF-K21, including the pill, here on this thread:
Since the CNQ driver that I’d used before was a double-board, and since the UF-K21 is tiny, I didn’t think that I’d be able to get the driver into the UF-K21, so I decided that I’d mod the ledsupply.com triple to parallel, so that I could drive it with a “normal” driver.
I originally tried the now-paralled triple with the original UF-K21 driver, and it actually worked, but it no longer had modes.
I’m guessing that was because the driver was originally designed to driver just a single XM-L emitter and the increased current draw with the triple was causing it to lose the modes.
So I decided to try a Nanjg 2.8 amp driver.
The driver I got was this one, because I thought it’d be kind of neat to be able to switch mode groups without jumpering stars:
After modding the triple star to parallel, I removed the front-end of the UF-K21 pill so that the triple would sit directly on the front of the pill.
I then replaced the original UF-K21 driver with the Nanjg driver (the FT driver was a press-fit into the UF-K21 pill).
However, after putting it all together, the light wouldn’t turn on :(…
The problem turned out to be because the UF-K21 is designed such that the end of the battery tube is unanodized, and has to make contact with the edge of the pill to complete the circuit (the UF-K21 is a twisty), and, since I had cut off the front of the original pill, the rear edge of the pill was too far forward, so the battery tube end couldn’t contact the pill.
So, I took some wire, and wound it around an 18650 battery several times, making a small “coil” that fit into the head of the UF-K21 to “extend” the pill end. I also found a small retaining ring in my junk box that was able to thread into the UF-K21 head “behind” my makeshift coil/pill extender, and which would hold the coil in place once everything was screwed into the head.
One final thing is that I had to do was to remove the small spring from the Nanjg driver. Otherwise, the battery tube couldn’t screw far enough into the head. [Note that the light only will work with button top batteries now.]
After all of that, I then had a working 16340 triple :)…
Turned on:
Disassembled:
Nanjg 2.8 amp w/retaining ring:
White wall (high, ~1m):
I guess that the Luxeon emitters are now being driven about about 0.9+ amps each, which is just slightly under the Luxeon-spec’ed maximum, but, while I could probably add some 7135s to the driver to increase emitter current, I think that I’d be pushing my luck with such a small host.
