# 20 K Kilowatt search light...Lumens?



## Spence (Dec 5, 2007)

The U.S.Air Force AC 130 Spectre Gunship utilizes 20,000 Kilowatt search lamps to illuminate targets (enemy implacements). What is the formula to convert watts/kilowatts to lumens? Anyone willing to guess how many lumens these monsters are? The police helicopter's "Night Sun" search lights have always been referred to in candlepower however, I never thought of that as very accurate. Anybody know the lumens for the "Night Sun"?




 :thinking:


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## Mel_PL (Dec 5, 2007)

Spence said:


> The U.S.Air Force AC 130 Spectre Gunship utilizes 20,000 Kilowatt search lamps to illuminate targets (enemy implacements). What is the formula to convert watts/kilowatts to lumens? Anyone willing to guess how many lumens these monsters are? The police helicopter's "Night Sun" search lights have always been referred to in candlepower however, I never thought of that as very accurate. Anybody know the lumens for the "Night Sun"?
> 
> 
> 
> :thinking:



It must be 20 kW.
20,000 Kilowatt is 20 MW which needs a small power plant to ignite.
I can't recall where I saw a 20 kW metal-hallide bulb, I only remember it was pretty expensive.

-- M.


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## BVH (Dec 5, 2007)

Don't know the Lumens rating but I believe there is a typical "Lumens per watt" factor for the different types of lighting - HID, incandescent, etc. I think the Lumens rating of the Xeray 50 watt HID is 5,800, or 116 per Watt. The Lumens per Watt figure for the Welch Allyn 10 Watt lamp is 500 I believe, so even the Lumen's per Watt factor could be different for different classes/sizes of HID. If you use something in the middle, the the Night Sun might be somewhere 92,000 Lumens? I'd love to know the Lumens produced from my 60" carbon Arc. It's only rated in CP - 800,000,000.

I think one of the modern retrofits of my Carbon Arc is the use of a 20KW lamp. The old AN-VS?, which was a trailered, water cooled military light used a 15 KW lamp or close. The bulb back in the 70's I heard was $10,000.


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## Helmut.G (Dec 5, 2007)

a 20 kW HID has about 2000000 lm iirc


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## BVH (Dec 5, 2007)

Did some quick searching. Lamps this high in wattage are usually HMI. HMI are typically 85 - 118 Lumens per watt so Helmut.G hit the nail on the head.


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## tebore (Dec 5, 2007)

Helmut.G said:


> a 20 kW HID has about 2000000 lm iirc



Ok so now we just need to make it hand held. 

Where do even get 20kW from a helicopter anyway?


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## BVH (Dec 5, 2007)

The helicoptor Night Suns are 1.6KW, not 20KW. Typically, the 20KW's are retrofitted into the old, WWII searchlights which are run off of a generator.


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## PhantomPhoton (Dec 5, 2007)

BVH said:


> ... The Lumens per Watt figure for the Welch Allyn 10 Watt lamp is 500 I believe, ...



Actually it's around 50 Lumens per Watt. They put out around 500 lumens @ 10 watts.

10W * 50 Lumens/Watt = 500 lumens. I think you were remembering the 500 lumens figure. 

If they could figure out a 500 Lumens per Watt 10 W HID that would be the end all of flashlights.


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## BVH (Dec 5, 2007)

Opps, that's what I meant to write but it didn't come out that way. That would be one heck of a maglight!!


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## Ken J. Good (Dec 5, 2007)

WARNING: Thread Drift Ahead....

I am working on a Carbon Arc handheld which should be the ultimate handeld.
It's kinda hard to hold in your hand though.....nevermind....:naughty:

BVH: In high-school I worked at the local theatre as a projectionist. They had the old carbon-arc (and when I say old, I mean old) projectors.

Everytime I got in that booth, I wondered if I was going end up as a pile of smoking ash...More than once I cracked the bars together without the shield down......Ouch...Ouch...Ouch...:thinking:

Somehow between waking people up in the middle of the night at school camps/fieldtrips and touching off a those square flashcubes in their eyes at close range and my early employment I guess I was destined to play with these things...


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## 65535 (Dec 5, 2007)

BVH should talk, I do believe this man owns the only 20Kw light on the forums, at slightly above the efficiency of halogens, I would guess he's getting around 75 lumens per watt for a nice round 1.5ML


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## Mr Happy (Dec 5, 2007)

You guys should check out my design for a 20 kW flashlight here: http://candlepowerforums.com/vb/showthread.php?t=181752

The incan bulb is rated at about 600,000 lumens according to the spec sheet.


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## MikeLip (Dec 5, 2007)

Mr Happy said:


> You guys should check out my design for a 20 kW flashlight here: http://candlepowerforums.com/vb/showthread.php?t=181752
> 
> The incan bulb is rated at about 600,000 lumens according to the spec sheet.



Well. that's certifiably insane.

I *LIKE* it!


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## DM51 (Dec 6, 2007)

MikeLip said:


> Well. that's certifiably insane.
> 
> I *LIKE* it!


Lol, this whole thread is insane! I love it!


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## BVH (Dec 6, 2007)

65535, if I'm reading your post correctly, you're refering to me as owning a 20KW light. My light is actually still operating with its original carbon arc system so there's no bulb, just one heck of a bright but small spark created between two, cerium cored carbon rods which is magnified by a tiny 5' reflector plated with Rhodium.

There are a couple of people back east that are taking these original lights and gutting the carbon arc mechanism and retro-fitting an HMI bulb and ballast. I think I've seen them rated at 15KW, 18KW and 20KW. The claim for the 20KW is 1,000,000,000 candlepower. However, I'm a purest when it comes to military hardware and prefer to keep it as original as humanly possible. And I don't concede them their 1 billion CP claim. As far as I'm concerned, I still have the brightest light ever made. And I am definitely NOT prejudiced! :nana:

This is a fun thread!


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## 65535 (Dec 6, 2007)

BVH, it's a light not a lamp, that thing is truly insane, I still consider it as a lamp, as it is a self contained system, even if it boasts truly pathetic lamp life.


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## HEY HEY ITS HENDO (Dec 19, 2007)

Ken J. Good said:


> WARNING: Thread Drift Ahead....
> 
> I am working on a Carbon Arc handheld which should be the ultimate handeld.
> It's kinda hard to hold in your hand though.....nevermind....:naughty:
> ...


,,,,,,,,lol nice one Ken !!


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