9200mcd S-ranked Nicias in the PT Matrix

I bought some of those S-ranked Nicias from AB recently and thought I'd try them out in my PT Matrix module.

Getting the module apart was the hardest part. I used a jewelers' screwdriver and carefully pried the lexan over the catch tabs.

Pliars were used to unscrew/remove the drive-screw battery contacts that hold the circuit board in place.

Removing and replacing the original LED's was not too much of a problem for a person with reasonably good soldering/ circuit board skills.

The results, while not dramatic, I believe are noticeable. Since I don't have two of these modules to do a side-by-side comparison with, it's harder to quantify the improvement.

I think it now has a slightly tighter beam than before and it seems to throw farther. The center spot seems a bit more concentrated, and is noticeably bluish just as it was before.

While not the brightest LED light available, it is voltage regulated and will run at (relatively) constant brightness for many, many hours from just two cells. BTW, it will run on a single cell - albeit somewhat dimmer than on two.

In summary, this mod improves the performance marginally without affecting power consumed whatsoever. I'd say it was worthwhile.

FWIW - John

John;

Thanks for the info on this. I had been wondering the same thing, as I have a Matrix Module myself.

Hi Charles,

Glad I could help.

Here's a little more info...I removed and replaced the original LED's one at a time. After removing one, I lined up the replacement by putting it into the front "reflector" housing and then carefully placed the the circuit board on top. Pay attention to the "flat" side of the LED's as that's the polarity indication. Note that the board won't seat completely until applying the soldering iron to the pads on the rear for the new LED. Then, the board seats completely and the LED is lined up perfectly. I used a little alcohol and a Q-tip to clean the solder resin from the board before reassembly.

Those little drive-screws were reinstalled by gripping the head with pliars and twisting clockwise while pushing. I then used a metal rod and tapped them down to ensure they were fully seated.

I did some research on the MAX1678 step-up converter used in these and noted that it's set up with a fixed 3.3V output, and can drive up to 90mA using 2 cells, or 45mA for 1 cell.

It is possible to make the output voltage adjustable by adding a 500k or 1 meg-ohm mini potentiometer. Wiper connects to FB (pin5) and remaining terminals connect between OUT (pin8) and GND (pin6). Alternatively, a 2-resistor voltage divider using calculated resistor values could be used instead of a pot.

It *can* be done, but it's tiny work. It'll involve removing the entire SMD chip, and cutting the copper trace to isolate FB (pin5) for the potentiometer connection. A possible alternative might be to carefully "lift" pin5 from the ground connection and solder directly to the pin. I'm not sure if the pin will tolerate bending like that.

Seems I recall reading a thread here that the early versions had the potentiometer...too bad mine doesn't.
/ubbthreads/images/graemlins/icon23.gif

I'll have to find the right potentiometer and get a much smaller soldering pencil before attempting this next step.

Great to hear from you, Charles. I hope the info is helpful...

John

I use my Matrix Module for sitting at my computer keyboard and that, when I don't want the bright overhead lights on. Back in 1998, when I had moved to Columbus, Ohio, I bought this headlamp at the Walking Company. It turned out to be a rebranded PT Solo. When I learned of the matrix module for it, I decided to get one.

After quite a bit of use, the light color has become more white than the bluish/purplish that it was originally.

I had been wondering if upgrading the LEDs was possible, and worth doing. Since you say there isn't that much increase in output, I don't think I will bother. This headlamp fills my everyday usage nitch in my light inventory.

Charles,

It's entirely possible that my perceptions could be skewed by the fact that I have several LED lights ranging in brightness and color. There are no two that are alike. If I've been using a Photon Light and pick up my Lambda Illuminstor, the LI seems brighter than I remember. The LI appears white with some slight bluishness, then I look at my LGI and it seems much whiter still. My eyes play tricks on me.

I perceive that the 9200mcd's are an improvement, though as I said I can't do a side-by-side comparison, nor do I have a light meter. Bottom line for me is that swapping LED's posed little risk and offered improvement potential. Only down side might be time /effort wasted-YMMV.

PS - Just for fun, I may consider replacing the LEDs with lead sockets so I could swap or even mix/match LEDs as new/different LEDs become available.

It might be useful, if you got a second Matrix Module and leave it as is. While not a light meter, it would still serve the function of comparison. I know they aren't cheap (not in my budget). As I write this, I am using my Solo/Matrix. It is my favorite for close in stuff.

Besides, a 2nd unit would be your backup, in case you messed up the first one. /ubbthreads/images/graemlins/wink.gif