Matrix headlamp -> Luxeon Star conversion

Coherence

Newly Enlightened
Joined
Mar 7, 2001
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Bend, Oregon
Here is a fast and easy conversion:

Get the Princeton Tec Matrix headlamp, remove whichever lamp module is in there. Trim the corners on the Luxeon Star with wire cutters (just a little bit), round them out with a file. Use one of the screw mount holes on the LS to slide over the keyway in the headlamp. You can solder wires directly to the terminals at the bottom of the lamp module area.

I put in a magnetic switch, and wired a 15K resistor across it. Has the always on mode, barely glowing for years (well, at least a year hopefully). Slipped a 'rare earth' magnet between the clear plastic head and its rubber cover, the magnet has approx. the shape of a watch battery. It is held very securely in place by friction. When you rotate the head, it has a range of 'on' and 'off' for each rotation. Very solid switch action, the head is so smooth and quiet that you can hear the magnetic switch click on and off.

Nice thing about the whole project is it is reversible, you can recover both the LS and the headlamp if you want. Also you get a professional result, still waterproof and a nice bright beam.

I have not done any runtime tests on it though. Just had fun making it.
 
Sounds good Coherence. A reversible mod, too !
I really like the idea of a magnetic switch. sounds cool.

Ummm, simple though you make it sound - any chance of a switch details and "photos for dummies" version ?

Lite-Lover
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Sorry I can't post any photos, no digital camera handy.

The magnetic switch is a glass tube about 1/2" long and 1/16" diameter, I epoxied it to the side of the LS module. If you want to get one go to a hardware store in the alarms/security section and look for window sensors. They come as a pair, a magnet and the detector. Open up the detector and the switch is inside.

As far as heat goes, it doesn't seem to be an issue. I ran the light face down for a while and can't detect any heat buildup.
 
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Coherence:
As far as heat goes, it doesn't seem to be an issue. I ran the light face down for a while and can't detect any heat buildup.<HR></BLOCKQUOTE>

The heat won't come from the light itself like it does a regular flashlight.

In the Luxeon Star, most of the heat is radiated from the aluminum circuit board at the bottom of the whole LS assembly, so putting the light face-down isn't going to heat up a table in a hundred years - though the area towards the back of the light's head may begin to feel warm after awhile.

The manufacturer recommends the Luxeon be heatsinked when run at its rated 350mA for more than intermittent duty.

Somebody else on this thing retrofitted a cheap "D" flashlight with the Luxeon Star, and made his own heatsink from some kind of sheet copper; this will work very well.

Sorry I can't think of who this is (it's after 1am here and I've been up since 7 yesterday morning working on my website, so right now I'm not the brightest bulb on the tree). :-O
 
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR> The heat won't come from the light itself like it does a regular flashlight.

In the Luxeon Star, most of the heat is radiated from the aluminum circuit board at the bottom of the whole LS assembly, so putting the light face-down isn't going to heat up a table in a hundred years - though the area towards the back of the light's head may begin to feel warm after awhile.

The manufacturer recommends the Luxeon be heatsinked when run at its rated 350mA for more than intermittent duty. <HR></BLOCKQUOTE>

What I did was to run it face down for about 20 minutes, then quickly open it up and feel for any heat escaping. None that I could feel.

Since it is only running on 2 AA cells I am sure it is not getting more than about 170mA, run on the bench power supply at that rate the LS just gets a little warm.

However, at 350mA the heatsink does get quite hot. Something to definitely keep in mind if you are driving to LS to rated current.
 
Can you give us an idea of comparative brightness? I'm quite interested in increasing the brightness of my Matrix and converting several other flashlights, some of which are 2 cell devices. Naturally, the Nichias don't quite cut it on a 3V power supply, so the LS looks like a viable LED.

At 170mA rate of drain, this would be a good application for all those who bought large quantities of Lithium AA batteries a while back at that sale.
 
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Coherence:
Anyone with a light meter care to sacrifice a couple cells and post the results?<HR></BLOCKQUOTE>

I'm going to do that *soon*- I want to finish the test on the two Rayovac AA rechargable alkalines first-
 
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR> I'm going to do that *soon*- I want to finish the test on the two Rayovac AA rechargable alkalines first- <HR></BLOCKQUOTE>

THAT is what is cool about LED's - I remember reading about your test days ago, runtime tests can take weeks! Try that with an incandescent.

The Luxeon Star seems to work well from barely glowing to full brightness. Somebody has got to make the adjustable flashlight with it, rotate the head from off to bright for instance. Anyone have an idea for how to do this so it is reliable and efficient?
 
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR> Can you give us an idea of comparative brightness ... this would be a good application for all those who bought large quantities of Lithium AA batteries a while back at that sale. <HR></BLOCKQUOTE>

To my eyes, with fresh 2 AA batteries the LS is about 7 times as bright as a Photon 2. I was thinking the same thing about the Lithium cells as they hold their voltage better as they discharge.

I had a couple of 4 year old lithiums laying around, currently they are discharging through an LS, still running (dimly) since Monday. When first hooked up they were about 7 times the Photon, after 8 hours they were about 2 times the Photon. After 72 hours about 0.1 times the Photon. This is not a very good test since I don't know how much capacity was left in the cells so maybe these numbers are a 'worst case' scenario. Anyone with a light meter care to sacrifice a couple cells and post the results?
 
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