Overdriving incandescent bulbs?

Greetings,

I am trying to get a bit more juice out of my Lumilite 6v lanterns (alkaline lantern batteries). I removed the existing KPR 4 cell bulbs and for fun tossed in a Radio Shack XPR 103 Xenon 3 cell bulb (rated 3.6v 800ma, ave life 36 hours). Nice improvement! Much whiter light and a larger hotspot for shining around the back yard. I have no clue what this will do to bulb life, but I like it.

I dug through my goodie locker and found a new Maglite Xenon 3 cell bulb. This is a more expensive bulb and looks a little more robust as well. I'm thinking this might be a better option. It ran for exactly one second. No flash, just one second of burn, then nada. Unfortunately, the Maglite bulb had no specs listed.

I am also considering revving up my 3D maglights, but would appreciate a bit of guidance before I start pointlessly burning up $5 bulbs.

Any thoughts on why the RS xenon bulbs seem to handle the extra juice, but the Maglite bulb puked?

Are there any guidelines as to overdriving bulbs (Krypton, halogen, xenon) with regards to number of volts or maybe a percentage of overdrive that gives a jump in brightness without trashing bulb life?

For grins I just dropped a 2D KPR bulb into my 3D maglight. Not much difference that I can notice. I really need to get two of these side by side for a better comparison, but not the brightness jump I was expecting.

Any insight is appreciated.

TR

i've been learning a lot about the over-driving of incan bulbs by browsing the WA website and putting in different drive levels on many different bulbs.. they don't make PR bulbs that would fit in directly but you can get them potted, and you can just learn different bulb types and such.

I've developed a driver to keep the voltage down with incans.. http://hotdriver.rouse.com and an even simpler design you can build with just a couple parts is in the works... look in Bats. incl. for ludicrously simple hotwire driver.

-awr

AFAIK, kryptons handle overdriving better than xenons. As for flashing bulbs, your battery's state of charge also plays a major role. You're more likely to flash a bulb on 'fresh' batts as compared to 'rested' or 'used' batts.

A 2-cell bulb on 3 batts is ~50% overdrive. Your batteries are most likely a lil bit depleted since the bulb is still ok.

A 3 cell bulb in a 4 cell light is only a 25% overdrive. This will reduce bulb time significantly, but you have a lot less chance of "flashing" the bulb as you do when you use a 2 cell lamp in a 3 cell body.

Thanks for the feedback from all.

Right now I'm not really looking for any fancy mods, (especially if I have to break out the soldering iron and be required to think). :huh2:

Right now I'm just looking for a drop in bulb (biggest gain for least effort)

So far I really like the upgrade with the 3 cell xenon bulb in the lanterns. I'll probably leave them there and see how the bulb does for life span. I can probably tape several spare bulbs inside the lantern body for a quick change in a pinch.

At rated specs (according to the info on the back of the RS bulbs), the krypton is good for 15hrs, halogen 25hrs, and the xenon 36hrs. Pretty big difference, but not of much use if overdriving the xenon blows the bulb. So far I don't really care for the RS halogen 4 cell bulb I tried. The hot spot focus is really odd (a rectangular coil) and too many artifacts overall. Any thoughts on how halogen compares to krypton when overdriven?

Also, are there any favored bulbs for the 3D maglight?

Thanks, TR

Bravo25 said:

A 3 cell bulb in a 4 cell light is only a 25% overdrive.

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Wouldn't it be 33% overdriven? 12V / 9V = 1.33.

common math error.. it would be 25% underdrive putting 4cell bulb in 3cell host.

33% overdrive is very close to a lot of my 'hotwire' welch allen solutions.. i suspect that the bulbs here are actually designed with thicker filaments they might take to a 33% overdrive pretty nicely, only testing would answer that question.

-awr

Jeff,

It was interesting to read your numbers. I'm looking again at the 3.6v rating on the xenon bulbs and am still surprised the bulbs are intact with the 6v lantern batteries. I've got both lanterns just burning right now to see how they hold up after a 15 min steady burn. If these hold up it is a great solution.

A nice thing about the Z-Lite lanterns is the spare bulb holder inside. I'll go ahead and tuck one of the KPR113 bulbs in each lantern as a back up.

As for my 3D mags... I'll probably toss a LED upgrade in. I really need a long running task light for these, not a short-burn thrower.

Too bad there aren't that many high quality 6v or 4D lanterns left. In my days of youth I had some of the lanterns that used the 6v sealed automotive type bulbs. All metal, high quality and very rugged. It seems like most of the 6v lanterns these days are plastic toys trying to look like sci-fi weapons. To get a really high quality lantern requires going to an expensive rechargable. These Lumilite Z-Lites are a great compromise, but I don't think they are still being made. I haven't seen one in a store in many years.

Keep us posted on the success of the "3 cell Mag White Star Krypton" in your flashlight. I may have to pick one up to play with.

Cheers, TR

Well, darn. I didn't carefully read your post. I just assumed the Z Light was 4D.

Agreed. Most 6V lanterns these days a just terrible. Apparently they still make the Z Light because I see this LumilitesCorporateSpecial. Nice looking light.

For your purposes for your 3D I think you'll like a 3W LED.

Talking about 6V lanterns and LEDs made me remember that I saw this lantern at Sears for $30.00. It is $39.00 at the web store with free shipping. I don't know if anybody has posted about it. I looked closely and couldn't tell if it was a Lumileds but it was definitely a 3W side emitter. Two years ago I would have leaped on it. I'll bet it has pretty good runtime. I don't like plastic much but I have a few plastic Colemens. This Dorcy looks pretty cool albeit trying to be a sci-fi toy. Dorcy_3W_4D_Lantern_at_Sears.

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- Jeff

Jeff,

The Z-lites use 6v spring top lantern batteries. They came with adapters for 4D cells, but in side to side comparison the lantern batteries were brighter. I don't know if they have greater current capacity or if there is just a greater resistance with the 4D adapter. I also have one 4D Z-lite lantern. The batteries lay flat in two rows of 2 (not in a cube shape). It is a more compact lantern.

I looked at the Lumilite web site and they have several nice lanterns listed. The problem, no stores carry them. Even on the web I couldn't find a single site that sold the Lumilite lanterns. Weird.

I did find a Dorcy 4D rubberized lantern today. Looks a lot like the 4D lumilite lantern. Seemed pretty rugged and look like it means business. I picked it up and made a run by Radio Shack for another XPR103 bulb to put in the new Dorcy. If the bulb holds up it will be my new "Walk with the kids on Halloween" flashlight. The big maglights don't balance all that well and the metal is just plain cold on the hands. The Dorcy lantern should be much easier to carry, warmer handle, and much larger reflector. I'm guessing the weight difference is negligible.

I like your idea of a 3W LED for the maglite. I just haven't found one I like. I recall seeing some recent reviews where some of the 3W led drop-ins were smoking and burning out in very short order. I also don't recall any of the 3W PR LEDs that were regulated. I like the option of the EverLed, but I'm not sure if the 1W output is high enough and the price is way too high ($36-$50 for a bulb!) I was running through Target today and stumbled onto their LED flashlight 10% off sale. They have the Dorcey 1W 3d on its own special for $16 bucks. I didn't have time to to stop then, but I'll probably go back tonight and pick one up to play with. I love the robustness and basic utility design of the Maglight, but if I can get an entire flashlight for less than an upgrade bulb I really need to consider getting a couple of Dorcys (even if they are not quite as tough). I just looked at some of the Dorcy reviews and it looks like upgrading to a 3W in the future may be plug-n-play.

I followed your link to the Dorcy 3W 4D lanterns at Sears. I just couldn't carry that thing with a straight face :laughing: . I do like the butt ugly square orange light shown in the bottom corner:rock: . I'm just too old school.

Cheers, TR

pizzaman said:

I just couldn't carry that thing with a straight face :laughing: . I do like the butt ugly square orange light shown in the bottom corner:rock: . I'm just too old school.

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TR - I heard that. Needs a Darth Vader helmet to go with it. If I pick one up please feel free to make fun of me. I like orange job too. Rechargeable for $35.00.

I don't have a link or name for you but a couple of months ago there was a disussion about an affordable Mag lookalike 3 Watter. Probably if you asked a question in the LED forum someone would remember it. Seems like several guys bought them and liked them.

Sounds like you may have your lantern deal solved all on your own. Great!

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- Jeff

Follow up...

I had a chance to play with my new Dorcys. The 3D 1W LED is a decent performer. If I can figure out how to pull out the lens I'll stick on some clear contact paper to act as a diffuser. I really use my mags mostly for task/work lights. If this works, I'll have to look into some of the radical mods for my maglites.

Now back to overdriving stuff:

I took my new Dorcy 4D lantern (6V) and fired it up. It has the smallest hot spot of any flashlight I own. Too small really. Stupid small. The label says
"True Spot Reflector". No kidding. I went ahead and replaced the stock bulb with a Radio Shack XPR 103 Xenon 3 cell bulb (rated 3.6v 800ma). Wow, even brighter! No smoke, no flash, no clue on ultimate bulb life yet.

I took it outside to test the small hotspot. I was a bit dissapointed playing it around the backyard. My Z-lite lanterns with the same bulb have a much larger hotspot and would be a much better solution for checking strange noises at night. I then took both lanterns out to the front where I could get some real distance. Wow, the 4D Dorcy has amazing throw. At heart I'm really a flood kinda guy, but the small hotspot and amazing throw of this light were just plain fun. I was solidly lighting up anything I could find in my suburban neighborhood. I just don't need a "spotlight" like this, but it is just too much fun to dispose of. It worked great to point out stars to the kids too.

This xenon bulb should be toast with this much overdrive, but it is hanging in strong. If the kids let me follow along on halloween night I should be able to see how the bulb handles an hour or more of use. Good test for the batteries too. I'll keep my SF A2 close at hand if the bulb deep-fries on my outing.

TR