Yet another Mag hotwire mod...

I've been experimenting with the 3x123 in 2C mod with various lamps and have been having some fun. Except for burning through 2 boxes (60) 123 cells in 2 months. I figured it's about time to do something rechargeable, but that means going to something a bit larger in form factor. So I dusted off my very old and seriously abused 3D Mag body and started looking at what I could stuff inside...

I experimented a bit with 6xNiMh AA cells as an alternative, and that worked pretty well, but the voltage was a bit lower (although output was more stable over time).

Then I tried 7 x NiCad and the lamp I had been running off of 3x123 and 6 x NiMh went <POOF!>. Hmmm... that was unexpected, and a bit dissappointing. Especially when I couldn't find a replacement lamp (I could have sworn I had more)...

So now I have this big ugly Mag stuffed with 7 x NiCad high-rate shorty cells and nothing to put in it. Then I remembered that dive light I melted a while ago /ubbthreads/images/graemlins/hahaha.gif (long story) and the lamp for that was rated to run off of 6 x AA cells, or 9V. Hmmm... that sounds like it has possibilities.

Popped it in and hit the switch, and WOW! /ubbthreads/images/graemlins/cool.gif

The lamp is from an Ikelite PCa light, and I'm not absolutely certain about its rating, but I believe it's something like 7.2V at 1.05A (7.5W). So I really wasn't expecting anything special compared to the 1.7A+ lamps I have been running, but I was very pleasantly surprised. This sucker puts out some light!! And it focuses a bit tighter than the higher amp lamps with their large filaments. Beam pattern is major ugly though. So I tweaked the lamp a bit for better centering and dropped in my PMR and I am having some fun tonight. I still can't believe how much light is coming from this relatively low amp lamp.

I have no idea where to get replacements (dive shops I guess), or how much it costs - it's probably not cheap since it is a specialty lamp made exclusively for Ikelite - then again, it is a PR Halogen, not some high-tech gas-arc, so it's probably not scary expensive either.

Anyway... I'm gonna go play some more with my "Baby Mag Charger" and I'll let you know if I find out anything more about this lamp.

Aloha, iG

Hey,
That's quite cool, Geek. Sometimes the greatest satisfaction comes not from outright brightness but from the serendipity of finding something unexpected that works where it wasn't meant to go. BTW, what do you use for a charger?
Wilkey

iG,

Very nice. It sounds like that bulb is drawing quite a bit more than 1.05 amps.

I can see you have tungsten in your blood. If you don't melt a little plastic and flash a few bulbs, you're really not getting the most out of hot wires. /ubbthreads/images/graemlins/grin.gif

Paul

Wilkey,

Yea, this is a real surprise. I just can't figure out how this thing can put out so much light without loads of current? I mean the lamp is designed to run from 9V (6 Alkalines) so it's not really being over-driven (much). It rivals, and possibly even surpasses the GH24 (6V/1.7A), which at the over-drive levels I'm running them at (3x123 Lithium power) should be putting out around 14 watts. That is significantly more than the PCa lamp should be pushing, but the PCa lamp out throws the GH24 hands down (and uses a lot less battery power in doing it). Heck, this thing probably won't even melt the stock Mag relfector.

/ubbthreads/images/graemlins/thinking.gif

PaulW,

It's rated at 7.2V and 7.5W (which would be 1.04A), but spec'd for 6 Alkaline power. So it is being slightly over driven, typical for bright flashlight lamps.

I have tried driving it from 3x123 as well as my 7 NiCad rig and brightness seems to be comparable. The GH24, on the other hand, flashed on the NiCads. Not sure why. Either the Lithiums are being pulled down in voltage much lower than I thought, or it was a fluke (bad lamp)? I've got some more GH24 lamps around here somewhere, but I can't seem to find them at the moment. Only other GH24 I have is in my 2C now, and I don't want to "test" that one until I find my spares.

I wonder who makes this PCa lamp for Ikelite?



All it says on it is "IKE 6 CELL" /ubbthreads/images/graemlins/icon3.gif

Anyway, the NiCad batteries I'm using are Sanyo CP-1300SCR short Sub-C cells (I've seen them called 2/3rd Sub-C & 1/2 Sub-C). They are High Rate cells that seem to be popular for RC use. I saw one site that did 15 & 20 AMP load tests on these things, and they sure didn't run long at those levels (only 1300mA capacity), but they did deliver! /ubbthreads/images/graemlins/faint.gif

Did the old PVC and tape trick to get them in the D Mag without rattling. 7 just barely fit in my 3D body. Got them from BatteryStation. They were tabbed, but I just removed the bottom tab and rolled up the top one to make a button. I charge them individually with a couple of conventional chargers using some computer case type thumb screws to take up the slack.

I expected their output to be similar to 3x123 under load (perhaps a bit more) but with a more stable discharge curve. But the flashed GH24 has got me wondering if I'm giving too much credit to the 123 cells (been through dozens of those in the 2C and haven't flashed a GH24 yet).

Aloha, iG