Presenting the KL-41

This is *NOT* my idea for starters. It's an idea borne in the swamps of Louisiana, conceived by none other than Chop. Presenting the KL-41. Intended as a host for the up-and coming Luxeon III.



It's the top of a KL4 with the integral reflector married to the ***, err, bottom of a KL1. The idea was to get more meat for heat generated by the new 3W LEDs. I added the idea of using the KL1 circuit (buck/boost) in conjunction with the reflector in the KL4 and taking measurements of the circuit board shows that the KL1 circuit will fit in place of the KL4 circuit with some (hopefully) minor modifications. Initial examination shows that two holes in the KL1 board need to be reamed toward the edge of the board. I haven't done it yet, but I think it may work.

CM

IN-teresting!

This is serious stuff folks. Along the same lines as yclo's KL-adaptor, only more useful /ubbthreads/images/graemlins/grin.gif

The lower KL1 body is actually not needed to use the KL1 buck/boost since the board fits inside the KL4, almost perfectly I might add, at least dimensionally. So you can keep the look of the KL4 or if you prefer the "ribbed" look, you can marry the two together. The drawback is the cost, but hey, it's only money.

CM

MAAAAD scientist at work.

/ubbthreads/images/graemlins/grin.gif

Ok, Ok, I can feel the skepticism and I can hear you guys rolling on the floor. Really, this is no joke /ubbthreads/images/graemlins/grin.gif

Aw man.. You just made the KL-Adaptor useful! Now I'll have to go think up something else that's useless...

It would look better if KL1 has a larger diameter. This is so serious man. /ubbthreads/images/graemlins/ooo.gif

What's the KL1 + E2e doing behind there?

CM,
I put a KL1 and my KL4 under the knife. I will post pics later as it is very late right now. replacing the KL4 circuit with the KL1 circuit will not fit. The smaller diameter of the KL1 circuit will not allow the heatsink to seat properly. I did manage to get everything wired up and the KL4 1W is definitely something to be sought after.

Running a Q3J at 1A with the KL4 reflector throws as good as my E2e.

The mod with the KL1 circuit in the KL4 may still work after modifying the heat sink. Need to cut lots of chunks out.

I'm going to bed now to dream about the KL4 and KL1 that I destroyed tonight.

[ QUOTE ]
yclo said:
Aw man.. You just made the KL-Adaptor useful! Now I'll have to go think up something else that's useless...

[/ QUOTE ]

/ubbthreads/images/graemlins/grin.gif

Chop,

I don't quite understand. if the diameter is a tad smaller, what's causing the interference? I'll look into that.

CM

CM,
The KL1 circuit has components mounted all the way to the edge of the board, whereas the KL4 circuit does not.

There's got to be a way. I'll look into it some more when I get back from church.

I took a quick look at the parts last night and and concluded that I have been taking the easy route using one of Dat2zip's converters.

Yes, McGizmo beats us again. Probably time to report on my failed attempt to use the stock KL4 circuit, modified to become a buck boost like the KL1. Don has donated a host for this mod and the idea is to use the KL4 circuit and modify it using a trick in the KL1 which turns a boost to a buck/boost. After about three laborious nights, I got it to work. But three laborious nights is too much and using Dat2zip's converter is faster. I guestimate the amount of cuts and jumps (some of which are very precise) would amount to about 2-3 hours...not worth it. Oh well, glass half full says it was a "partial" success.

Chop, I see the interference problem. OK, time to go back to the drawing boards for other ideas. I'm a pretty pigheaded guy who refuses to quit /ubbthreads/images/graemlins/grin.gif

CM

I think I got around the interference problem. Both parts are sot-23 packages. One of the parts is for open circuit protection. You can remove that if you don't need that feature. Or you can clip off the corner of the package since the die is at the center. The other part is a 2N2907 type transistor and must remain since it's part of the feedback. You can also clip the corner of that but don't get overzealous. I used an xacto knife. I tested the transistor after clipping and it's good. There are four holes on the KL4 circuit and you can notch off the KL1 board where the four holes are. It may not be possible to make a notch where a resistor is in close proximity but you can clip off the corresponding plastic tit on the can. Hard to describe without pics but if you have these taken apart, it's easy to see what I mean. I realize it's easier to use dat2zip's circuit but for anyone anal enough to want to keep the light "All Surefire Inside" this would work.

I haven't hooked anything up yet since I realized I have a life outside of mods that need attention.

CM

because I'm a bit slow at times, what is the advantage to combining all of these parts, in throw , brightness and runtime. I can see the advantage of over driving luxeons cause it winds up being brighter which is always good for me, especially with the cost of 123 batteries being what they are.

I got the KL1 circuit to work in the KL4 head. OK, no big deal, other than it cost you a KL1. So I played around with the stock circuit a bit and studied my schematic. At high overdrive levels, Vf of the LED starts to approach and even exceed 4V. Li-Ion open circuit voltage is 4.15-4.2V. This will be reduced by losses in the circuit (Schottky, sense resistor etc.) to about Vf or below. This is perfect. With a single Li-Ion cell, one can drive a 3W LED using the stock KL4 circuit and modifying the sense resistor for the higher current drive. So back went the KL4 circuit with a new sense resistor set for 878mA. The results were gratifying. I've never seen the KL4 reflector used on the 1W and I gotta say it's a great beam.

Obligatory comparative beam shots:

1W Q3J high dome driven at 878mA vs stock KL4


Same modified KL4 vs 1W in a modified PM6 reflector (700mA)



McGizmo showed similar beam shots but not a side by side so I wanted to complete the picture so to speak.

This mod has very limited utility in that it will not work with 2x123 and a very low Vf LED will probably be overdriven though Mr Bulk would argue that we're just pushing the LED a "teensie bit harder" /ubbthreads/images/graemlins/grin.gif But for you lithium ion junkies like me, this is an extremely easy mod to do. I like this better than using the KL1 circuit. It's slightly more efficient. The KL1 circuit draws 1.2A vs 1.08A for the KL4. It cost you a KL4 head and a sense resistor. And you can't use 123's. Haven't tried on a single 123 but it should run better than the stock 5W since it draws 300mA less current using the same power source.

CM

PS. Pictures were taken in broad daylight so there was substantial ambient light. No flash used in pictures.

Schweeeet!!

CM,
I too got the KL1 Circuit working in the KL4 and it was nice, but like you said, it came at too high a price. I was, however, impressed with the performance of the 1W Q3J @ 1A with the KL4 reflector. It had just about the throw of my E2e.

I also have to give a nod to Surefire at this point. Considering that a bozo like me went wild with a soldering iron inside of both the KL1 and KL4 stripping both to their components, it is surprising that both are now in the same shape they were in before I started. Surefire builds a tough board.

BTW, what was the stock value of the sense resistor that you changed? What did you drop the value to? I don't run my KL4 on anything but Pilas so this would be a good mod for me. I much preferred the beam with the 1W as opposed to the 5W. Very nice side spill with THROW.

CM,

Why won't your new head work on 2x123? If it's the KL1 circuit in there, shouldn't it just go into buck mode on 2x123?

That beamshot is great. It looks like the 1w with the KL4 reflector provides a little more flood than the PM6 reflector but still gives a decent hotspot.