Re: What\'s this? Another KL1 mod
Hey guys,
I've done a bit more messing with this KL1. The driver in it is remarkably similar to the one used in the older KL1, but the newer one is larger in diameter.
Well, first things first. As I said, I heated this thing up to about 250 degrees to get things to loosen up. I still had to wrestle with it to get it open, but I did.
What came loose easily was the lower portion of the light which exposed the anode contact housing and circuit board.
These are a tight fit in there. I tried several times to remove the heat sink from the upper portion of the head with the circuit board still attached, but I became afraid of damaging the converter.
Here's what it looked like...
There was just enough room in there for me to desolder the leads from the converter, so I did that to give me a better shot at the heat sink.
Here's what I saw after removing the converter...
As you can see, this sink suffered a few minor battle wounds. I tried the collet method, as mentioned above, but it seems that each of the newer KL1s, like the older ones, has its own personality and difficulty of disassembly. When I tried the collet method on this one, the threads actually turned in the collet. What I wound up doing with this one is the old fashions needle nosed pliers improvisation. It finally came out. Once I got it apart, I found the culprit.
There's a rather TIGHT fitting o-ring used in the upper section of the sink that screws into the upper portion of the head. I hope you can see it.
This o-ring makes re-assembly rather difficult as well.
Here's the top of the sink after disassembly.
And the lens, optic, and its retaining ring.
Now for the converter. The older KL1 converter is on the left. Note the similarities. Of course the one on the left is missing a couple of parts, like the inductor that was used to revive the newer unit.
Now, the larger resistor on the newer KL1's board is a .68 ohm. I'm assuming that this is the current sense resistor. The smaller resistor (1206 size) is labeled 75M. I'm assuming that this is the inductor sense resistor. Does anyone know what 75M means? I hit it with my DMM and it read 0 ohms, but my DMM won't measure less than .1. Now I'm saying 0 ohms, but it actually read .2, which is what it reads when just touching the probes together.
When I overdrove the KL1, I used a .47 ohm resistor in parallel with the .68 ohm resistor. On a 2X123 battery configuration, I got around 700mA, but it wasn't steady. It kept declining in current level settling down around 600mA. I suspect that this has something to do with the inductor sense resistor, but I'm an electronics idiot so I don't know.
When I initially modded the KL1, I also ran a .1 ohm resistor in parallel with what I believed to be the inductor sense resistor, but this resulted in the inductor cooking itself. I don't know if it was due to too much current going through the inductor or what. It may very well have been due to a short occurring when I put it back together. This thing isn't as idiot proof as the older KL1s. Since I didn't have anymore replacment parts, I didn't want to risk it with Pitbull's light.
Another observation that I made was that I couldn't get more than 500mA out of the circuit when running on a single 123.
All I can say right now is that I'm going to have to get a couple of my own KL1s for experimentation purposes.
In any case, after all was said and done, I do have to say that the only really worthwhile thing that this KL1 NEEDED was a reflector. Other than that, this is a nice piece of equipment.
I'm going to need to make a tool for the heatsink out of steel or something. It's goint to need to be strong.
Does anyone know how hot I can go with heating this thing before I melt the dome on the luxeon and the optic. I wanted to go to 350 degrees, but wasn't sure. I know that 350 will soften red loctite. I used to have to do that to remove compensators from 1911 barrels back in my shooting days, but I don't want to cook anything on the light. At 350 I'd be getting dangerously close the melting solder joints too.
If anyone has any suggestions, let's have it. I want to get rolling on doing more of these. At this point, I do want to get rolling on more of these, but I just don't know that it would be worth it to spend $60 just to add a reflector to the KL1. It really doesn't need anything else and when you get to that price point, you could have just gotten an Aleph II head and pretty much had it built to order.
