Susceptibility of LED lights to EMP Blasts?

Just wondering: How susceptible are the LED lights to EMP (Electromotive Pulse) blasts? What I'm wondering specifically is; would these lights hold up better than sophisticated computer equipment and other electronics. I'm sure they are probably vulnerable to some extent. Any ideas?


JK

Metal-bodied lights like Arc, Tektite Excursions, CMG, and SureFire would probably be alright; plastic-bodied lights would probably end up with popped LEDs.

If I remember correctly, EMP from a nuclear weapon can generate around 50,000 volts per meter of wire exposed to the EMP.

You expecting trouble?

I've never personally had a failure of an LED that I could attribute to EMP. I try to avoid locales where it might be a possibility /ubbthreads/images/graemlins/tongue.gif

When too close to a nuclear blast, the usual flashlight problem is that there are no eyeballs left to see the light with, and no hands left to turn the lights on
/ubbthreads/images/graemlins/smile.gif

Yeah, I guess this preparedness mindset is just a joke. Thanks for all the levity, after all nothing will ever happen here in the US, right? /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/smile.gif /ubbthreads/images/graemlins/smile.gif

It was very funny!

But sliding down that slippery slope, I work in the NBC building where Tom Brokaw was sent the anthrax, and just yesterday my wife was saying, I think you should have one of those Evacu-8 smoke hoods in your desk at work...so I've started an office bailout bag. Now, let me see about EMP-proofing my desk... /ubbthreads/images/graemlins/wink.gif

daloosh

This topic has been discussed on CPF a number of times. You can probably find it by searching. As the LED Museum said, the general conclusion was that metal bodied lights are pretty well protected.

They probably hold up better than these things:

Unfortunately the Evacu-8 hood does not protect against nuclear/bio/chem agents.

From what I recall, Peter Gransee threw an Arc AAA in a 1200 watt microwave for 20 seconds. /ubbthreads/images/graemlins/crazy.gif This was his EMP simulator! The AAA worked fine with no problems, the minimag blew it's bulb.
If you get hit with an EMP blast that would nuke an Arc AAA or AA... I would think that flashlights would be the farthest thing from your mind.
I would not worry about terrorists using nuclear weapons, too easy to detect, very hard to build, wildly expensive etc. Chemical weapons are much, much easier to build and very inexpensive.
Horribly disfigured people screaming in pain from chemical exposure makes better news than a bunch of dead people. If I was worried about it, chemical/bio weapons would be what I would prepare for.
Watch out for semi-truck drivers in chemical gear driving 18-wheelers with really smokey exhaust stacks.

If I remember correctly, the gist of the past threads on this topic were that the led flashlights should be pretty much OK except for an exceptional emp exposure....in other words, a close blast.

I doubt that it would have much effect on a flashlight of any body composition.

Most flashlights don't present much antenna length. 30 years ago the CD folks advised that EMP would probably knock out radios in police stations but leave the radios in mobile units functioning, because of their smaller antenna length. Also, 30 years ago mobile radio antennas were a great deal longer than they are now -- multiples of flashlight lengths.

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BentHeadTX said:
If you get hit with an EMP blast that would nuke an Arc AAA or AA... I would think that flashlights would be the farthest thing from your mind.


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Something about the brightness of a thousand suns makes a flashlight seem so puny, ya know.... /ubbthreads/images/graemlins/poke2.gif

/ubbthreads/images/graemlins/grin.gif

-Jason

I've heard of EMP weapons that can be built that don't involve nuclear explosions. It's also possible to set off an atmospheric nuke with the deliberate intention of knocking out only electronic equipment. So it's really not a moot question.

Also, I've never understood the specifics about the microwave experiment. Do you get electric fields on the order of 50,000 V/m (Craig's figure above) inside a microwave oven? I don't know. Perhaps there was some estimate performed somewhere, but I never came across it. /ubbthreads/images/graemlins/confused.gif

The exact number escapes me, but I seem to remember the V/m field strength within the oven cavity of the common (700W) microwave oven was less than 200V/m.

One of the trade rags (EDN, or EE Times, or the like) ran a little quip about how easy it would be to build a one-time-use EMP generator. Components were minimal, a car battery, some copper pipe and very small amount of something will explode. The gist of the article was along the lines of how easy and cheap it would be for an ill-willed malcreant to make a real mess of a bunch of e-gear. Decently sized EMP's don't all come from binding or splitting atoms.

Will I be able to buy more batteries if the ATM machine is toast?

Ordin

I thought putting metals in microwaves would ruin the microwave? Yet I keep reading about how people are putting their lights in the microwave to test them... hmmm, someone enlighten me!

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utomatoe said:
I thought putting metals in microwaves would ruin the microwave? Yet I keep reading about how people are putting their lights in the microwave to test them... hmmm, someone enlighten me!

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The primary danger in this is the possibility of overheating or burning out the magnetron tube in the oven. Another significant risk is arcing (sparking) in the oven cavity between the metal flashlight body and the walls or floor of the oven cavity, creating a fire hazard.
One way to mitigate the potential danger of the magnetron tube overheating is to place a cup of water in the oven with the flashlight or other metal article. And to reduce the chance of arcing, place the metal article on a plastic or wooden stand, keeping it an inch or more above the oven floor and away from the oven walls.

I think the perceived danger of nuclear weapons has shifted from 'efficient' cold war-style nuclear weapons to 'dirty' terrorist-style weapons. If you combined 1 pound of low-grade plutonium with a truck bomb using diesel-fertilizer explosive, downtown Manhattan could be poisoned for thousands of years. EMP would not be an issue IMHO.

There is no probability worthwhile mentioning that your light will NOT survive EMP.

There is no weapon currently that will cause an EMP at a level that could ruin a light without ruining you.

There are several that are under study that might wipe out a light...(that is not the main intent) but a metal casing on a light will provide more than enough protection to the electronics.