Arc AAA Turquoise to 26K mod

[chimo]

After getting some 26K mcd white LEDs I decided to give modding my Arc AAA Turquoise a try. The Turquoise was bright but it had a lot of beam rings and the LED was scuffed up. By far, the hardest part of this mod was unpotting the head. The rest was a piece of cake.

I started by carefully uncrimping the head. Next I heated up the head and pushed out the "plug" by pushing on the LED with a wooden dowel. With a little effort the whole plug slid out.

I used heat and a small pick to flake off the softened epoxy. This was an iterative thing - heat, pick off epoxy and repeat until it was all gone.

When I got enough epoxy off, I heated the legs of the LED from the battery side of the board and wiggled out the LED and capacitor soldered to it. I was careful not to bend the LED legs out of shape. I unsoldered the capacitor from the LED and removed the remaining epoxy from the board.

Next I bent and trimmed the legs of a new 26K LED to match the one I took out. I soldered the LED/cap assembly on the board and tested it. It worked fine, so I re-assembled the head. I didn't re-pot the head (just in case some 50K mcd become available). All went well and here are the results.

The unpotted circuit board.

Assembly with the new LED in place.

Beamshots:
Cree UV @ 100mA no reflector/optics
Arc AAA w/ 26K mcd
Q3 w/ TW0J
MiniProIII w/ TW0J

Paul

 

[M_R]

So that's what they look like inside /ubbthreads/images/graemlins/naughty.gif. Great mod Chimo!! It's amazing how much light 1.5 volt can generate in your ultimate sleeper AAA /ubbthreads/images/graemlins/happy14.gif

Edit: Can anyone identify what’s in there and could definitely confirm if running Li-ions at 4.2 volts is safe in ARC AAA's as I don't have the inventory or the cohonas that cy has to be doing this. /ubbthreads/images/graemlins/wink.gif I presume it should turbo charge the output on the stock LED

Thanks,

Matthew

 

[greenLED]

Isn't there a chance of crushing the circuit if you don't pot it? I keep seeing this, but I haven't actually read (or seen pics) of a crushed circuit.

 

[chimo]

I suppose there is a chance of mechanical failure if you stress the LED, however, it is recessed and shouldn't be abused too much. The Arc will lose its water resistance but that's not an issue for me. I suppose I could have used some softer potting material like silicone but I didn't bother.

Here's a great link for top mark identification for transistors and diodes. Please feel free to post other reference links here to similar material.

SMD code link

Paul

EDIT: A note on crushing. There is an inner rim inside the head that the circuit board sit on. That eliminates the risk of crushing from the pressure of the battery. The curcuit board is fairly thick so unless you crank down really hard on the head, board flex should not be a big issue.