2 Cell mag-bulb overdriven in a 3 cell maglite

Hi,

I writing this to let you know that I found that one can overdrive the 2 Cell mag-bulb in a 3 cell maglite.

It saves having to figure out how to cram 4 C Cell in to a 3 D Cell maglite and can be also used for the 3 C Cell maglite.

This makes for a cheap upgrade, also I found its less likely for the blub to blow if run by rechargeable batteries.

I'm using 3 AA rechargeable batteries in AA to D cell convector in my 3 D Cell maglite.

I also tested a frosted bulb that I took out of an magnifying glass.

It was 2.4 V and I was amazed how it produced a light from the maglite with tone down rings and hole in the middle characteristic of the maglite beam.

Does any one know where I can get krypton PR bulbs that have a frosted finish to them or alternatively how to make them.

Very nice,

This is where alot of people on here start. Tinkering around with the stuff laying around the house just to see what happens.

I very much like the nice white color of an overdriven incandescent bulb too!!

Dr Phil Panter said:

Does any one know where I can get krypton PR bulbs that have a frosted finish to them or alternatively how to make them.

Click to expand...

This is entirely in theory, but common glass etching uses HF paste and they are avaliable for this purpose, get some of those and paint on bulb briefly should work.

Dr Phil Panter said:

I writing this to let you know that I found that one can overdrive the 2 Cell mag-bulb in a 3 cell maglite.

It saves having to figure out how to cram 4 C Cell in to a 3 D Cell maglite and can be also used for the 3 C Cell maglite.

Click to expand...

My experience with this mod has always been instaflashing. I would assume this is due to driving it at 150% ie 3.6 vs 2.4V. Interestingly I've never flashed a 3.6V bulb when running 4.8V. I would again assume that this is possible due to only overdriving it 133%.

However if you're having good luck then by all means continue!

As for etching, a light touch with 300 grit sandpaper and a little time will do a fine job.

Is this the regular bulb or the Xenon?

Is the Xenon more tolerant of overdriving?

Sgt. LED said:

Is this the regular bulb or the Xenon?

Is the Xenon more tolerant of overdriving?

Click to expand...

Hi,

The bulb is a normal stock maglite bulb for the 2 D Cell maglite running in a 3 D Cell maglite.

I've also got a number of standard krypton bulbs rated a 2.4v 0.75 A

But what impressed me was the frosted bulb, again a 2.4v that produced a beam, semi-free of the characteristic rings and donut hole associated with maglites.

The beam look more like something you would find on a quality LED, however there was some lost to throw.

Xenon bulbs for torches in the UK are difficult to find in the high street. So I haven't been able to test the overdriving of a Xenon bulb.

Also they are costly, a single Xenon PR blub is around about the £4 mark in the Uk. A good quality non-maglite krypton bulb is abut £0.80p

The light burnt bright and white from overdriving the krypton bulb and so far I've only had one blow.

That was due I suspect to me switching the torch on and off quickly, the bulb was also pretty old as it was out of a 2 AA torch that I had at my office.

Also if I cant find or make a frosted bulb, I found some plastic that was part of the covering on a pack of cheap "CD-R discs" also from tescos that could be made in to a cheap diffuser lens.

I'm looking to come up with a really cheap upgrade that can be applied to any maglite or similar torch that is also practical.

It seems like Maglite's krypton bulbs can take more overdrive then the Xenon ones can.

Over driving a 2 cell bulb with 3 cells might be pushing it quite a bit.

i've never instaflashed a 2-cell bulb while overdriving it with 3-nimh. but trying to do the same with alkalines or lithium guarantees a blown bulb.

I tried running a 3-cell Magnum Star on 4 fresh alkalines... I re-invented the photo strobe.

OK hows about the 2 cell bulb on 1 18650?
Poof?
A 3 cell bulb ought to live, right?

Hi,

I believe the key to overdriving a bulb is with only a slight increases in power.

When you run a 3 D Cell torch with new alkaline batteries you are in a sense overdriving the factory bulb.

When attempting to overdrive any bulb your better of using rechargeable batteries in my opinion, so not to overwhelm the bulb ability to cope.

Also I notice overdriven bulbs heat up more than usual and I'm wondering if this plays a role in their demise?

I ran a 2.4V 0.75 A krypton bulb for a couple of minutes then took of the lens of to use as a template.

I notice a faint hint of smoke and a bit of heat on unscrewing the lens.

Dr Phil Panter said:

Also I notice overdriven bulbs heat up more than usual and I'm wondering if this plays a role in their demise?

Click to expand...

Yes. The closer the filament gets to the melting point of tungsten, the faster the atoms boil off and eventually cause the filament to break.

However, overdriving a hot filament actually gives you more lumens per watt than you get from the rated voltage. Power consumption goes up, but visible light output goes up even more.

In my experience the 2 cell Maglite krypton bulb does not last long in a 3D Maglite, but lasts a little while in a 3C.

3 cell Maglite bulb works okay in 4AA configuration as well. That seems pretty reliable in my experience. Even more so than the 2 cell 3C thing.

I had also find that a 3 cell maglite krypton bulb overdrives nicely in my 3d mag with 4 2700 mah powerex aa's in 4 aa to c cell nexcell adapters with the spring reversed. I also have a ucl lens which helps out too. It has nice white throw. Nimhs work nicely for overdriving lamps.

I burnt out one of my 2D bulb when I use 3xeneloops in series with it. It was working perfectly until I started to do strobbing mode that it went Poof! I agree it was bright and nice yellow beam.