Streamlight Stylus goes Luxeon

LED_ASAP

Enlightened
Joined
Dec 13, 2002
Messages
567
Location
British Columbia, Canada
Streamlight Stylus is the commercial light with the look and feel of a real pen. However the AAAA batteries used in them are still relatively rare and quite expensive. Although you can get "pseudo AAAA" batteries from a 9V battery, you have to load them in reverse, which is a nuscence and often forgotten until you find the light refuses to come on. The 5mm Nichia LED in them are also not the brightest nor the whitest. I have long planned to convert one to use Luxeon, and to use "pseudo AAAA"s extracted from a 9V battery in the "normal" nipple-goes-in-first way. With the sale from cmendoza, I finally got a host to undertake this project :D

The original Stylus is a resistored DD light using 3 batteries. There are two options to convert it to Luxeon---one is to squeeze a Luxeon into the space of a 5mm LED (plus the holder); the other is to cut the light short and use two batteries with a boost converter. The first one would give the option to make a brighter light because you don't have to lose efficiency to the converter and you have more energy from 3 batteries. However the construction of the Stylus made this option very difficult---there is a brass insert near the LED end, and it made the ID of the tube thinner than the OD of a Luxeon. The only viable way, after some fiddling, seemed to be to cut the light and use two batteries plus a converter.

Despite the tail end being brass, the rest of the Stylus body is actually aluminum. It can be cut very easily with a tube cutter. The ID of the tube opening is very slightly larger than the OD of a Luxeon emitter, and the wall thickness is ~0.6mm.

The converter is still my favorite ZLT circuit. It did take a while to figure out a layout to squeeze all the component into a 7mm circle (except for the inductor, which was sandwiched between the Luxeon and the converter board). The converter board have the negative connection in the middle of the circle, so later the batteries can go in nipple-first. The converter and the Luxeon was epoxied together to make a lttle plug.

plug3.jpg
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plug.jpg


I put some glow powder around the emitter dome to give the finished light a little cool factor :)

The next question is the optic. The battery tube is too small to use any commercial reflector effectively. The only option would be to use a lens. The tube can hold a ISP quart-die LED nicely (~7.7mm OD). So my first attempt was to cut the lens off one. But during my polishing steps, I found the resin used in the ISP LED was too soft and it scratches easily. Eventually I had to take a 9mm Acrylic ball, cut it in half, and trim the OD to fit the tube, and go through the polishing to get an appropriate lens.

The various pieces were epoxied in place, and my new creation was born:

size.jpg


According to Energizer's datasheet, 9V batteries have 625 mAh capacity (probably measured with only 10mA load. Under heavier loads, the capacity will probably drop at least by half. In order to provide a useful runtime, I set the battery draw to a mere 100mA, which means there should be at least 3 h or so near full brightness runtime.

The glow powder showed nicely under the lens:

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I drilled a small hole in the tail switch and also put in some glow powder:
glow%20tail.jpg

glow%20tail2.jpg


The beam is square-ish, typical for a HD plus lens configuration.

beam.jpg


The light output is decent for a light of this size.
brightness1.jpg

left: PEAK Matterhon; middle: Streamlight Luxeon; right: new Arc AAA

brightness2.jpg

Reduced the brightness on computer to better show the relative intensity.

This truly pen-sized light can fit nicely in a shirt pocket. The stainless steel pocket clip is reasonably strong so you don't need to worry about losing the light in normal conditions.

My first real-life use of this light was when I needed to inspect some leak in my attic. The smaller OD came in very handy when I held the light between teeth :D There was enough brightness and throw to allow me see what went wrong :crazy:
 

carrot

Flashaholic
Joined
Dec 6, 2005
Messages
9,236
Location
New York City
Sweet mod!

I've got 5 Styluses sitting on my desk, and I'd love to figure out how to do this mod without cutting one up! The form-factor is perfect the way it is (for me, at least) and I'd hate to ruin a good thing. I'd think it would involve a TIROS-type lens... is there any way to make a custom TIROS?

A little more info on the sandwich would be nice too.
 

xochi

Flashlight Enthusiast
Joined
Nov 23, 2003
Messages
1,426
Excellent Mod , Leds!

It's been awhile since I've seen something new here!
 

Pathlight

Newly Enlightened
Joined
Apr 25, 2002
Messages
46
Location
Fullerton, Ca USA
Hi LED ASAP,

Can you please tell me the best way to remove the regular 5mm led to re-
place/upgrade it? I tried pushing it very hard but no luck. Like your idea and
your mod. Thanks. Gordon
 
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