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Burning flashlight


paul1598419

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What do you mean by a burning flashlight? There are no flashlights that can burn like a laser. Even high powered spot lights can't do that.
 

Cel

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Pour petrol onto it. Take a match and light it on fine. You have a burning flashlight.




Seriously, flashlight's primary purpose is illuminating stuff. So, visible light. (Exceptions are specialty flashlights, e.g. UV light)
To burn stuff, you don't need visible light. So infrared is fine.
But wait, what is a source of a lot of infrared radiation? Exactly, incandescent lights (halogen and HID).
High powered LEDs should be fine too, but they need good cooling.


Fun stuff: the heat you feel from a campfire isn't hot air, it's infrared radiation. You can check that by holding something in front of your hand (for example, your other hand) to absorb the radiation. In that case, you won't feel the heat anymore.
 

Nutball

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I thought there was a 5000lm flashlight that would light brown paper on fire at contacting range. I figure if that's the case, 30,000lm focused ought to burn something at least at 1ft away. It would still be fun to hold that much light.
 

paul1598419

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Then, by all means, try it. I can't wait for your results.
 

WizardG

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I thought there was a 5000lm flashlight that would light brown paper on fire at contacting range. I figure if that's the case, 30,000lm focused ought to burn something at least at 1ft away. It would still be fun to hold that much light.
I think the flashlight you're talking about is this (or an equivalent): FlashTorch - World's Brightest Flashlight | Wicked Lasers

It's a 100 watt halogen torch (the British term is far more appropriate for this puppy than 'flashlight') but you can have nearly the same fun from a 100 watt LED. I build very high power LED lights for <ahem> indoor gardening enthusiasts. If you set a piece of paper on top of a 100W LED you'll have a fire very shortly.
 

Cel

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Lumens are measure of visible light. Invisible light can heat stuff too.

Or does it really have to be mainly visible light in your case?
 

Nutball

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I'd rather have mostly visible light than IR. I know cell phone LEDs will nearly burn you if you color your skin with a sharpie, but I don't know how much of the light isn't visible. Probably not nearly as much as a halogen bulb.
 

steve001

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What do you mean by a burning flashlight? There are no flashlights that can burn like a laser. Even high powered spot lights can't do that.
Actually there seem to be flashlights that can ignite materials. Search YouTube.
 

Bacon

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I have a few led flashlights that can catch things on fire (not at a distance though). I haven't really seen that led before, but it looks cool. Everyone seems to be into the XHP-70 leds, they need less voltage and have about the same lumens. Its hard to practically dissipate the heat, and have a large enough reflector when its more than 1 though. I enjoy looking around on CPF and BLF; they always have some interesting builds/discussions now and than.

I like mtnelectronics and kaidomain for misc flashlight parts.
 

paul1598419

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I think the flashlight you're talking about is this (or an equivalent): FlashTorch - World's Brightest Flashlight | Wicked Lasers

It's a 100 watt halogen torch (the British term is far more appropriate for this puppy than 'flashlight') but you can have nearly the same fun from a 100 watt LED. I build very high power LED lights for <ahem> indoor gardening enthusiasts. If you set a piece of paper on top of a 100W LED you'll have a fire very shortly.
That reminds me of the early 1980s when I set up an indoor grow for a friend in Vancouver, Wa. It was done with some high power halogen lights. He got amazing indoor crops in a very short period of time. It surprised me how tall his corn plants got in only a few weeks. ;)
 

BowtieGuy

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Ah yes, I remember growing some very tall "corn" plants during that time period. I just used the natural grow light in the sky for mine. :whistle:
 

WizardG

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That reminds me of the early 1980s when I set up an indoor grow for a friend in Vancouver, Wa. It was done with some high power halogen lights. He got amazing indoor crops in a very short period of time. It surprised me how tall his corn plants got in only a few weeks. ;)
Yes, 'corn' will really stretch out under halogens; too much red light in the red/blue balance equation. I use actinic white and specially binned warm white parts that are individually controllable so you can pretty much dial up any internode length you want without affecting total yield per square meter much if at all. I've seen some very interesting 'corn' that was six months along but only about 18" tall, but with a 4" wide stalk at the base.
 

paul1598419

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It is what we had to work with back then. There weren't any better grow lights around in 1982. I do get what you are saying, though.
 




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