modified mag question

[Ross]

Hi folks.
Please be gentle, it's my first mod.....
I've got a 3D mag. I have made a tube which allows me to put 4 123's in the tube. I've perfected the battery contacts at the top & bottom and I know the power is getting through the switch. I've soldered a MR16 socket (via a heatsink) onto a PR base.
Now the problem(s).
What MR16 bulb should I use? Am I providing enough power to drive a MR16 bulb of even 20w? Should I use more batteries? Any other ideas? Should I cut my losses and get a 5W luxeon instead?
Please help, any advice is greatly appreciated!

Ross

 

[Rothrandir]

you're going to need to use a low wattage if you're only usein 4 123's in series.

i'm not too knowlegable in the electrical area, but i think you'd have a nard time with even 20w on the 123's...

nicads would work well, but recharging could be problematic. 12nicads will fit into a 3d, overdriving, and allowing you to run up to a 50w (thought at a greatly reduced runtime)

 

[Pellidon]

If it is a 12 volt 20 watt lamp it would draw about 1.6 amps (power=volts*amps) but it would only do that for a second or two. If it is rated at 12 volts and you are feeding it 12 volts from fresh batteries it will instantly get dimmer and dimmer as time goes on.

Most lights are "overdriven" 2 cell bulbs are rated for 2.4 volts typically, not 3. 4 cell at 4.8 or so. Once the rated voltage threshold is crossed, most incandescents will not glow once they have reached about 90% of rated voltage. House lights will wink out at around 90 volts. The bad thing is that the wire won't glow but still suck life from your batteries, quickly.

If the lamp in question is rated for 9 or so volts it will work for a while. General rule is for the voltage of the bulb to be around 60-75% of the applied voltage or the poor little guy will be bright briefly and never again. Higher rated lamps can take more overdriving than lower voltage ones. 50% almost always causes burnout.

check this thread (very long one) for inspiration. 283 lumen mag 2c

I don't do much overdriving besides using 3 cell lamps in 4 cell lights or the KPR112 in a 3x123 light so I am not the foremost authority. Hopefully those with more experience will chime in.

 

[PaulW]

Ross,

Let me just post a few things to consider about this mod. It's a pretty big venture for a first mod, and thought and planning will be important.

My tests have shown that 123s pushing out 2.5 amps work quite well, giving 20 minutes of runtime (M3 HOLA). At half that current (M3 LOLA or scorpion) they give 60 minutes of runtime.

Now 4 of them at 2.5 amps would draw down the voltage to about 9.1 volts. That's 22.7 watts. So, four batteries can do 20 watts. You'd get about 24 minutes of run time.

But if you use the Mag plastic reflector, you'll get (I estimate) less than 5 minutes of time before the reflector bubbles and melts so badly that it's unusable. In addition, the plastic lens would have to be replaced (a UCL would be okay).

Thus you need to think about replacing the lens and reflector. The cross-over where that becomes necessary is somewhere between 10 and 15 watts.

Another thing that needs thought is the specific bulb and the battery configuration that is best for it. You need to get just the right voltage and current. I know very little about the MR-16. I'm learning too, but maybe Ginseng will chime in. I know you can find out more (I plan to do it) by searching for the past few months on posts with "MR16" or "MR-16" with "Ginseng" as the writer.

Hope that's of some help. You've taken on quite a project here, but I think you'll be successful if you're persistent. Keep us informed with questions and findings. /ubbthreads/images/graemlins/smile.gif

Paul

 

[Ross]

Thanks for the help folks, I did wonder that the MR16 I was planning to use (20w) would be too much. I do have a 8v (but 50w) projector bulb with a MR16 base which I was eventually planning to use but its just too high a wattage to even glow.
The thread on the 285lumen Mag C was the inspiration for my mod, I know zip about electronics as well so I have to remember back to my school science days for the basics - obviously I have forgotten a wee bit over the years....
I have a UCL lens (from flashlightlens.com) but I hadnt considered the reflector, hmmmmm, have to give that one some thought.
I'll keep on reading / experimenting / learning / asking and hopefully I will get there in the end!!

Regards

Ross

 

[PaulW]

Ross,

I know where you're coming from. I saw that 285 lumen thread a month or two ago and got fascinated too. You know, the thread started more than 8 months ago, died off, and was resurrected. And there have been a lot of "Mag 2C" spinoffs and "Carley" bulb spinoffs from it.

I have learned a great deal from the folks here. I've been able to do some simple mods that really surprise my friends. The 4x123 with Carley 809 or 3x123 with Carley 612, for example, each crank out a beam of about 12 watts (okay if not left on for more than 10 minutes at a time). And the beam is very concentrated -- amazing throw. It'll turn heads.

Glad to have you joining our endeavors. Stay tuned . . . /ubbthreads/images/graemlins/blush.gif

Paul