Color temperature in incandescent flashlights: Argon vs Krypton vs Xenon

TNG

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Hi guys!

Since these flashlights are all incandescents with different gas inside a bulb, am I right stating that the color temperature in all these flashlights is the same (around 2800K)? Thank you
 

fivemega

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In general, color temperature of incand bulb depends on designer, bulb requirements and some other factors.
When higher color temperature is required, Xenon and halogen serves better which depends on designed voltage, designed bulb life and applied voltage.
If applied voltage is higher than designed voltage, color temperature and brightness will go higher but bulb life will be reduced.
For example a 6 volt / 1.7 Amp bulb with life of 100 hours, can be powered at 7.2 volt with higher brightness, much whiter beam (higher color temp) and bulb life of 10 hours.
I hope this helps.
BTW, welcome to CPF
 

yellow

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... In my experimente...
... for "normal" powered bulbs (say maglite an similar)

Krypton by far whiter than Halogen
no idea as to Argon
:thinking:
(are there bulbs stating argon-filled?)
 

bykfixer

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The original tungston filament light bulbs were vacuum'd of air. Early in light bulb history scientists discovered that in a vaccum tungston oxidized when heated. That produced light but also reduced remaining filament. Later they discovered gas would "bounce" oxidized tungston back onto the filament, thereby rejuvinating the filament.

The initial gas used was argon. Later argon was mixed with nitrogen. Still later krypton, xenon and halogen were used. It has been said that SureFire's process involved a secret mixture of xenon and krypton. Xenon and krypton do not "burn" as hot as argon so bulbs using those tended to last longer than argon filled so eventually the market favored those due to burning brighter while lasting longer.

Halogen was used not only for brightness but for filament lifespan. But extreme heat and potential for damaged glass from skins oils made them less popular with traditional markets. Xenon eventually had the most benefit but costed more to make than krypton so krypton stuck around, replacing argon bulbs for the most part.

Vintage bulbs up to the late 1960's were nearly all argon or argon/nitrogen filled until krypton filled bulbs showed up. Don Keller was given credit for perfecting the krypton bulb while working with Tony Maglica. It is unclear if that was before Maglite or during as they colaborated early in Kel Lite history. Tony (through Mag Instruments) milled parts to fulfill the demand for Kel Lites. Tony made brass shell casings for military use since the 1950's and at some point started designing and building flashlights. He and Don colaborated for a few years until the two alpha males figured it best they part ways. Later Tony was credited with perfecting xenon filled bulbs. Meanwhile LA Screw was dabbling in halogen filled bulbs in the mid to late 1970's. It is unsaid who started those. Or at least I have not found that info written down.
 
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novice

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bykfixer, that was another fascinating piece of incandescent history, thank you!
 

bykfixer

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My pleasure.

In labs in the US and South Korea there is work taking place where tiny mirrors and being used to redirect and appear to multiply light emitting from a filament along with recycling the heat to also make the filament more efficient. It has been stated that both are nearing the efficiency of the LED.

Will we see the return of the light bulb for everyday use? Probably no time soon if ever. But then again once upon a time the LED was seen as a "neat idea".
 
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thermal guy

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You ever see that lightbulb that's been burning continuously for like 100 years? It's in a fire house. Got a webcam on it and everything. The filament in is is the diameter of a pencil.
 

bykfixer

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I have not TG.

But I do remember there being a porch light to a museum in New York that was lit by one of Einstein's early bulbs that stopped working when there was a big ole blackout in the North East. If I recall correct it was in the mid 1980's and the rumor was aliens caused it.
When the power returned to bulb did not come back on (if I understood the story right).

A link to the top 7 oldest working light bulbs.
https://www.oldest.org/technology/light-bulbs/

Here's one from my bucket list:
A Franco toy pistol flashlight from about 1912. They were made for give away prizes by contract with Franco by a few newspapers way back in the early 1910's. The newspapers held contests to see who could sell the most subscriptions and the Franco's were one of the prizes. Very hard to come by but not especially sought after by collectors. I figured at least 2 zeros to acquire one if ever. I got it for $22 shipped.

B8-EBA129-9-AF8-41-A9-BAD0-45-CBB8-BE5-D83.jpg

Overall in good shape but parts inside to make it go are missing hence the low price.
Parts that would not be hard to make but I just keep it on a shelf as is.

It was a 2aa light.

Bonus: and reason for the post.
The original 1912-ish bulb still worked when 3 volts was applied.
It is probably filled with argon.

I have a few other working bulbs from that era that arrived in old flashlights and still work but I pulled them imediately and installed Tung Sol E10 bulbs from the 1960's.
 
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thermal guy

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Ya if you look they all have same thing in common. The. Filaments in those bulbs are huge!!!
 

chillinn

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My pleasure.

In labs in the US and South Korea there is work taking place where tiny mirrors and being used to redirect and appear to multiply light emitting from a filament along with recycling the heat to also make the filament more efficient. It has been stated that both are nearing the efficiency of the LED.

Will we see the return of the light bulb for everyday use? Probably no time soon if ever. But then again once upon a time the LED was seen as a "neat idea".

I am more optimistic about this new incan tech.

http://news.mit.edu/2016/nanophotonic-incandescent-light-bulbs-0111

MITNews said:
Whereas the luminous efficiency of conventional incandescent lights is between 2 and 3 percent, that of fluorescents (including CFLs) is between 7 and 15 percent, and that of most commercial LEDs between 5 and 20 percent, the new two-stage incandescents could reach efficiencies as high as 40 percent

LED has more or less reached it's peak efficiency, and LED is pushing towards better light (higher CRI) at the cost of peak efficiency.. Stick a fork in them. I was raised in natural light and suspect incan will return as a market force with only a modest improvement beyond LED efficiency, and then incan will progress in efficiency far beyond leaving LED in the dust. More pleasing color temperature and better color rendition accuracy will return, and I look forward to that day the last vehicle with LED has been scrapped and I am no longer blinded in pain by opposing traffic's offensive narrow-band unnaturally high temperature headlights.
 
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