26 Lumens / Watt from Incandescent?

[liquidium]

I was browsing around for bulbs that might have some modding potential, and came across the 6v xenon lamp used in the Pelican Big D. The specs:

Volts: 6
Amps: 1.5
Watts: 11
Lumens: 290

Based on the assumption that Pelican's numbers are honest, this hotwire produces 26.36 Lumens per watt. This is astounding effeciency for a xenon - can anyone comment on the honesty of Pelican's Lumen ratings in general? Are they overstated, or right on the money?
I couldn't help but notice that power draw for this lamp, assuming the V and A figures are correct, should be 9 watts - not eleven.

 

[Deleted member 684]

26 lumens / watt is not exactly impossible from a incandescent source. If you look over here at WA 01185 http://www.walamp.com/lpd/webstore/detail.tpl?partnumber=01185-U&cart=1091511799193788 you will notice the bare bulb measurement is already 27 lumens/watt. Pelican might just be quoting bare bulb measurements.

You're right about the wattage thing though.

Just my humble opinion.

 

[liquidium]

Such efficacy is hardly typical of bulbs below 12 watts. Even the majority of WA's hottest halogens don't exceed 23 Lumens / watt , based on bulb lumens.
WA's "store" (no shopping cart! /ubbthreads/images/graemlins/rant.gif) is also full of inaccuracies.

 

[liquidium]

Is there anyone out there who owns or has seen the Big D and can compare the outpout to another high powered light? /ubbthreads/images/graemlins/confused.gif

 

[mattheww50]

YOu can get that level of efficiency in Incandescents, but it comes at a price that most people are not willing to pay. For example take a good look at the estimated life of Welch-Allyn lamp cited previously. It is indeed 26 lumens per watt, it also has a 50 hour life! You get good luminous efficiency by raising the filament temperature, which does ugly things to lamp life. The WA lamp runs the filament at almost 3400K, which is why the life is so short.
Run it at 3000K, and you get perhaps 15 lumens per watt, but you get it for about 1000 hours. 50 hours is a bit short even for a flashlight. Usuall lamps run at such high filament temperatures have filaments that are quite fragile when lit. To be polite, between the life, and extreme fragility of the filament in operation, these lamps are not good choices for flashlights. If they take a licking, they are going to go out in a hurry.

 

[js]

[ QUOTE ]
mattheww50 said:
YOu can get that level of efficiency in Incandescents, but it comes at a price that most people are not willing to pay. For example take a good look at the estimated life of Welch-Allyn lamp cited previously. It is indeed 26 lumens per watt, it also has a 50 hour life! You get good luminous efficiency by raising the filament temperature, which does ugly things to lamp life. The WA lamp runs the filament at almost 3400K, which is why the life is so short.
Run it at 3000K, and you get perhaps 15 lumens per watt, but you get it for about 1000 hours. 50 hours is a bit short even for a flashlight. Usuall lamps run at such high filament temperatures have filaments that are quite fragile when lit. To be polite, between the life, and extreme fragility of the filament in operation, these lamps are not good choices for flashlights. If they take a licking, they are going to go out in a hurry.

[/ QUOTE ]

So many people seem to think this, but I will have to disagree. ALL of the SureFire lamps are xenon filled and all of them have a rated life of around 40 hours, and all of them burn pretty hot. My two brightest TL mods use the WA 1111 and 1185 over-driven to the point where they have about 11-12 hours of life according to the re-rating formulas.

I have not noticed any extra-fragility in terms of dropping and mechanically shocking the filament.

I have noticed that the 1185 sometimes insta-flashes if you turn on the light hot off the charger. Or actually, my field testers and customers have noticed this. It's never actually happened to me.

According to my information, the "life" in hours, is the average number of hours until the lamp falls to 85 percent brightness.

Whatever the efficiency of halogens may or may not be, it's better than LED's at power levels above 6 watts or so and gets better the higher the power level. 30 lumens/watt is not hard to acheive.

So, I don't know how you determine that "most" people are not willing to pay the "price" that comes with over-driven xenon's. Perhaps you are right. But then again, "most" people don't spend a lot of time on CPF or playing with LED flashlights. From what I've seen I think that

(1) over-driven xenon lamps are a GREAT choice for flashlights, and

(2) most flashoholics/CPFers are more than willing to pay the price of a short bulb life in exchange for greater efficiency, higher CCT, and more bulb-lumens.

 

[bwaites]

50 hours really is a reasonable bulb life.

Most stock flashlight bulbs are in that area, and no one seems to complain much. Look at the filaments on stock bulbs, they are almost gauze!

The high output bulbs have more robust size filaments, (for obvious reasons!!) but 50 hours is still reasonable.

I know I have more than 25 hours on a couple of my 1185's and can't tell that they are less bright than they were new. Same for a couple 1160's.

Bill

 

[js]

Yeah,

That's right Bill! You tell 'em. Plus, I recall Size15s saying that he had put some incredible number of batteries through his SF E2 lamp and it was still just fine.

 

[bwaites]

I do think its a little funny to worry about 50 hour, 10 dollar bulbs, when the Surefire M6 HOLA goes through 18 dollars of batteries an HOUR!!

Lets see $10 divided by 50 is 20 cents an hour!!! 18 dollars in batteries vs. 20 cents!!

Don't seem so bad to me--!!!!

Bill

 

[Ginseng]

Oh boy,

When I hear folks complain about a 50 hour life for a $3 bulb that makes 500 to 3,600 lumens, I just have to chuckle. Halogen bulbs are the most amazing bargains in the world of flashlight modding for the simple fact that it is so easy to swap out bulbs and batteries in the same flashlight body and obtain a range of output and runtime options that just is impossible to get from LEDs. A light with a fixed 5W LED is all that it will ever be. (of course, unless replaceable modules are employed) A Mag body though, can house a tremendous range of lighting options.

26 Lu/watt is good for any lighting system short of HPS, and any of the arc-discharge types. In fact, to get the most bang for the buck, I run my bulbs at slight to moderate overdrive and boost that number significantly. The HOLA in the Aurora makes 41 Lu/W. Pretty darn good for a light that makes over 4,000 lumens, runs 7-12 minutes and will recharge in 30 minutes. In addition to the monsters in this class, the same can be done for any incan bulb with varying degrees of succes.

Incans are powerful, flexible, can vary the beam color continuously based on the power supplied and are cheap, cheap fun. FWIW, the only bulbs I've ever burnt from a longevity standpoint are ones that I have pushed hard and enjoyed. Even so, very few bulbs have expired from "old age"...and I've played with many bulbs. Many.

I suspect Nik Tesla might show up here and bash incans again and extol the sublime virtues of arc lighting, but come on, how much does one of those bulbs cost? And who runs their lights for 60-90 minutes continuously on a regular basis? Again, don't get me wrong, I love LEDS and my primary EDC is an LED. But when I'm out back smoking a stogie and waiting for that damned deer to poach my plants, the club I'm wielding is the most powerful 3D incandescent flashlight in the world...for now /ubbthreads/images/graemlins/wink.gif

Wilkey
"I love my tungsten boiling and my nickle metal sizzling. I love my aluminum steaming and my glass scorching. I gots hot wires for nerves and double digit amps running through my silicone-lined veins. Baby, it's too dark in here...but it won't be for long." /ubbthreads/images/graemlins/wink.gif

 

[bwaites]

Wilkey,

That is perhaps the best explanaition of hotwire mania I have yet heard!!

This morning while putting the battery in the Mule I had it sitting face down on a newspaper. As I picked it up, smoke rose from the paper and off the front of the lens.

I had inadvertantly turned the switch on while playing with it and the 62138 bulb had gotten hot enough to vaporize the color ink on the newspaper and burn through the first 2 pages and most of the 3rd in the 20-30 seconds it sat there!

Gentlemen, these bulbs is HOT!!!

BUT....so much fun to play with. I'll be putting a 24 volt, 10000 lumen bulb in a spot body tonite!

Bill

 

[js]

GINSENG! GINSENG! GINSENG!

BWAITES! BWAITES! BWAITES!

Three cheers for hot-wire guys! That's right, we bad! We rock!

hehe. All that radiation from the hot filaments must have affected my brain there for a minute. Sorry, gentlemen.

 

[liquidium]

[ QUOTE ]
mattheww50 said:
[ QUOTE ]
It is indeed 26 lumens per watt, it also has a 50 hour life!

[/ QUOTE ]

At first glance, the short service life put me off - but assuming intermittent use two hours per session, two times per week, you get over three months of usage from your 4 dollar (or whatever) investment. It doesn't suck. 100 hours would be more like it, but the tradeoff is reasonable IMO, considering the efficiency, impoved color temperature, and brightness gained.

[ QUOTE ]
You get good luminous efficiency by raising the filament temperature, which does ugly things to lamp life. The WA lamp runs the filament at almost 3400K...

[/ QUOTE ]




Where can I find data on the actual operating temperatures of Welch Allyn filaments?

 

[liquidium]

Everyone:

I would agree with and understand that the level of luminous efficiency Pelican claims for this lamp is theoretically attainable; it's just that I found Pelican's numbers to be a tad suspect. After all, these dimwitted simpletons are incapable of even accurately presenting technical data for a modest handful of their own products - the wattage figure mentioned earlier appears to be off, and specified voltage for the Big D 6 cell alkaline is 7.2v. /ubbthreads/images/graemlins/rolleyes.gif
On the other hand, most here seem to think the 72 lumen figure for the PM6 xenon is accurate, if not conservative.

 

[mattheww50]

The color temperature is the equivalent spectral distribution from a black body radiating at the colour temperature. Incandesecent filaments are an excellent approximation to a black body, so absent any special filtering, the colour temperature IS the filament temperature in an incandescent.

 

[bwaites]

liquidium,

Many manufacturers state different voltages than the one actually intended for their bulbs. Most bulbs run in 6 volt flashlights are actually 4.8 volt bulbs, most for 4.5 volt are actually 3.6 volt bulbs.

Mag stopped speccing the voltages on the bulbs because of this kind of confusion, now their bulbs just say 3 cell, 4 cell, etc.

Their are two good arguments for this:
1. With alkalines (still the biggest flashlight market by far) the batteries aren't at their specced voltage for very long, if you ran a 6 volt bulb in a 4D torch, it would be under specced current very soon, the bulb would yellow remarkably fast.
2. Slightly overdriven bulbs run whiter, people like whiter!!

Bill

 

[Ginseng]

Liquid,

Thanks for bringing this back to your original question. I don't have enough experience to comment on Pelican's lights (although I do own several of their Sabrelights). I'd say that Pelican's bulbs in those lights is fairly potent. They make a 3-cell LA that seems to put out as much light as the Carley CL805 in a 3D Mag. The CL805 is the brightest aftermarket 3-cell bulb I've found and is significantly brighter than the stock 3-cell krypton bulb (148 lu to 34 lu). So, in my limited exposure, I'd say if they exercised the same engineering values, it could be easily be making 290 bulb lumens. And yes, the power should be 9 watts.

Wilkey

 

[Ginseng]

Bill,
I think you might be right. The other thing to keep in mind about overdrive and voltages is that the voltage will start dropping from the moment you turn on the light until the cells are exhausted or you turn it off. As such, the rerating values are technically only accurate at a single point during the discharge. The true rerating of a bulb/battery system must necessarily be an integration of the entire curve. For example, the take a look at the curves for the WA01160 on various 5-cell packs in this thread. A nominally 6V packs spends 13 minutes above 7 volts, 45 minutes above 6.5V, 57 minutes above 6V and 16 minutes below 6 volts.

Wilkey

 

[Ginseng]

Bill,

Ain't it fun to wield such power...for the cause of good, of course /ubbthreads/images/graemlins/wink.gif You should post a picture of the target in this thread. While some folks may consider this indicative of the gross inefficiency of incandescent lighting, I choose to view it as a broad power distribution. Afterall, not only do we make light, we get gobs of functional heat and intense UV as well. I mean, you can get a tan while cooking a cornish game hen at midnight. That's gotta be worth something /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/grinser2.gif

Wilkey

 

[liquidium]

Have you had a chance to experiment with the 3.7v [edit: corrected voltage: was 3.6; correct voltage for this lamp is 3.7] SL Stinger bulb? Streamlight doesn't publish luminous output for this lamp, but I think it should outperform the 100 lumen TL2 based on the numbers from Quickbeam's chart. I should see two of the Stinger bulbs at my door pretty soon.
The BIg D bulbs are sold in packages of two for about nine dollars - it's difficult to deduce from Pelican's description but I believe one each "primary" (600 lumens) and "backup" (290 lumens) is in each package. Bulb life specs aren't on this chart , but most of the Pelican bulbs seem to hover around the 30 hour mark. I've emailed Pel about this - if anyone would like to hear the answer let me know. Both 6.0 and 7.2 volt bulbs are available.