Can you mod the GenII KL3 head? I'd like to....

I've been going nuts here at CPF trying to absorb all the information on the KL5 and U2 that I can. But I recently looked at my KL3 head and thought - I wonder if I can upgrade the LED inside that instead. I did a heat test on it by leaving it on for at least an hour the other day to see if it got too hot if on long. It only got a little warm. I wonder if a slightly more powerful LED assembly would be possible. It uses a Luxeon III that puts out 30+ lumens, according to Surefire tech support. If you look up into it, you see four screws holding the LED assembly in. You would have to remove the head - to - body connection first however. But once the 4 screws are removed, the assembly should drop right out.

Has anyone opened one up? Do you think a 45-ish lumen LED (preferable a nice high-bin version) could take its place?

I think chop or Arcmania (can't remember) modded the KL3 before (mite be Gen1 tho, but I'm sure I saw gen II mods around). There is a regulation circuit inside the KL3, and battery current draw is 200ish ma; a higher bin Lux will of course put out more lumens, but I'm not sure what bin you'll need to get around 45 lumens from such low current.

Unless you remove the circuitry and stuff, then you can go for DD 80-100 lumens? Or maybe replace with a DB1000 (dunno if it fits)... haha.. with that killer optic, I think the light will rock, but will prob last for an hour or so only.

P/S Can someone link me up with a Japanese lights site that had lotsa pages of mods and other cool photos? I can't remember whose site it was (Arcmania or someone else's). It had like colored luxeon mods, modded KL3II I believe, 5w tower module in a C2 etc... thanks!

Hi 510jack, nice link.

But I remember its another one, I think there's 2-3 pages of modded lights; very nice, professional looking light pics. Maybe I was wrong and it wasn't japanese; I think it's one of our CPF modders sites.

Wow, some of those were cool!

Do any of you smart people know what I need?

It seems to me like you aren't exactly sure what you need yourself ... considering your recent activity in the last weeks and months. Maybe a first step could be to determine your needs exactly and then pursue this plan until the end with all the power you are now dispersing?
bernie

The KL3 is very ideal to mod to higher current drive. Geez, no need to swap out to a DB1000, it's just a resistor that sets the LED bias. The driver in the KL3 is very robust and can easily be bumped to 1.5A. I've done about 12 Gen 1 KL3's with a Lux III swap and bias up to 700ma typically, and about four biased at 1A to 1.2A. The 1.2A ones didn't even get as warm as a KL4. The massive head is great for dissipating heat. My recommendation is to probably leave the lux III that's in there if the output is good at stock bias, and then bump the current to the LED up to an amp or so.

Ok, well how would I do that? What resister would you recommend? I'm only looking to get it up to about 45 lumens, 50 MAX output. (Its' 30+ stock according to Surefire) Is it just a matter of removing a certain resistor and replacing it with a lesser ohm resistor? Soldering required? Obviously its going to decrease runtime. It has 3.5hrs runtime regulated now. I'd still like it to have 1.5 to 2hrs regulated runtime if I can. Thanks for the help....

KDOG3 said:

Ok, well how would I do that? What resister would you recommend? I'm only looking to get it up to about 45 lumens, 50 MAX output. (Its' 30+ stock according to Surefire) Is it just a matter of removing a certain resistor and replacing it with a lesser ohm resistor? Soldering required? Obviously its going to decrease runtime. It has 3.5hrs runtime regulated now. I'd still like it to have 1.5 to 2hrs regulated runtime if I can. Thanks for the help....

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Now bear in mind I'm referring to a gen 1 KL3. I don't know what they use on the newer ones. Once you get it apart, you'll see two resistors. One is R10 and the other R47. The 0.1 ohm (R10) resistor needs to be cut in half to drive the lux at around 700mA. This is easily done by putting another resistor of the same value in parallel. The R47 can be left alone for 700mA drive but I usually stack another 0.47 ohm resistor on top of that. You do need to be able to solder fine pitch SMT components. You also need to get some 1210 size resistors for power dissipation. If the newer ones use a different circuit, the same idea applies. You just need to determine which resistor is the current sense resistor (it's hooked up to one leg of the LED) and reduce it's value in the same proportion. You need a really good soldering iron with a fine tip for this kind of work. Flux also helps.

Whoa, Ummm ok. I'm starting to think this might be a little out of my league. My brain is starting to hurt....

Oh, man. Now my head exploded....thanks.

ahahaha I want to see someone take a new gen KL3 and mod it and see what it can accept. I wonder if it can take a PRT/McR27mm.... Or larger!

IsaacHayes said:

ahahaha I want to see someone take a new gen KL3 and mod it and see what it can accept. I wonder if it can take a PRT/McR27mm.... Or larger!

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I'll try to get one off B/S/T for a good price and sacrifice it.