EMP hardened???

[bdillahu]

OK, I know that nobody really knows, but...

Since a lot of us are interested in survival/disaster situations/etc. and since one of the considered situations is a small nuclear/terrorist device being set off, I have wondered about LED lights and lights with the various electronics in them being susceptible to EMP (electro-magnetic pulse)... I like LED's because day-to-day, they are tougher, etc... should I keep an old "bulb" around just in case? :-)

Just a thought.

Bruce

 

[robk]

Seems to me that they are surrounded by so much aluminum, they wouldn't be affected, unless you were at ground zero, where you wouldn't have to worry about light anyway. It's my understanding (from an old expert) that anything that has wires connected to it that are unshielded act as an antenna, and will "pop", but a lot of electronic devices that are self-contained and don't have "antennas" will survive mild EMP. This old guy still drives an old VW bug with a generator, because the diodes in an alternator will fail. He also believes in tube type radios for communication, as all solid state units will fail.
Rob

 

[BentHeadTX]

Rob,
You sound like the military minds from the USSR, they had all sorts of hardware that ran on tubes. If you are worried about it, there was discussion about EMP in the cafe' a few weeks back. Here is the skinny, the huge size of the PN junction on Luxeons will not be effected by EMP that much. The ultrasmall nanometer size of chips etc will be blown apart.
Soooooo, I have a couple of flashlights that can handle EMP. Mr. Bulks Mini LGI (3AAA direct drive Luxeon) and a 5D Mag with a 5 watt Luxeon and a simple resistor. My other ones are dead meat...but if it happens... we are all dead meat unless it is localized.
If it all goes to hell in a handbasket, you will see me with a mini LGI/5D Mag riding on my recumbent bicycle.

 

[robk]

And I'll be riding my 1984 Yamaha IT-490 dirt bike (magneto ignition - NO electronics) through the ruins, guided by my ARC LS!!
Rob

 

[tvodrd]

Surface nuclear bursts generate minimal EMP. Stratospheric (and up) are the strategic worry.

Larry

 

[robk]

Yes, that's true, but the likelyhood of a surface detonation is far more a possibility based on current terrorist activities. It would have to be a sophistocated weapon to be detonated 50 - 100 miles above the country.
Rob

 

[Gransee]

I couldn't find the thread but back in 2001, I put an Arc-AAA and a Photon II in the microwave. The microwave was set for it's highest power setting. The Photon II popped after less than a second but the Arc-AAA continued to work even after 10 seconds. After 10 seconds, I concluded the test. The Arc-AAA still works to this day.

Short of an actual EMP generator, the microwave does give some indication on how hardned an item is.

Basically, the amount of EMP required to harm the AAA would probally put you too close to the actual nuclear blast.

The LS should have a similiar resistance but less so towards the front since the optic is not a good insulator. However, the LS4, with it's solid metal reflector will increase the resistance.

All Arcs have a grounded housing and use input diodes to protect the circuit from static discharge. An interesting factoid: the presence of a strong magnetic field will cause your Arc to tempoarily dim. Once the field is removed, full brightness will be restored.

Bottom line, adding an electronic circuit to a flashlight does not automatically make it weaker. If you have good shielding and excellent overvoltage handling, an electronic flashlight can easily out-survive a dumb flashlight (as my microwave test indicates).

A cheap plastic flashlight with a bulb may have the coiled filiment fried by the heavy current induced by the magnetic field. Whereas an LED will be less likely to act as an inductor.

Peter

 

[Tomas]

Uh, Peter, you just lost your microwave priviledges at my place ... /ubbthreads/images/graemlins/grin.gif

 

[koala]

Ohh did you hear that? [ QUOTE ]
the LS4, with it's solid metal reflector

[/ QUOTE ] cool!

 

[snakebite]

anyone put an arc-ls in the nuker yet?
btw for s&g i put a 2d plastic light in a nuker.
the bulb flashed after 3 seconds.i think it takes that long for the magnetron to warm up.
replaced bulb and repeated test with light off.
it arced in the switch and popped the bulb again.
only damage was to the bulb.

 

[Eugene]

I've always thought that anything with a filament, light bulb or tube will pop in strong EMI since the filament is just like a tiny overdriven fuse and anything tube type is usually plugged in unless you have a big battery pack.

 

[js]

No. It needs to be long enough to act as an antenna, or small enough to be very sensitive to EM fields (and unshielded).

 

[BT1324]

I always thought that if u put anything in the microwave thats metal will explode and catch on fire...thats wut happened to my bag of chewy chips ahoy cookies hehe. The metal that holds the opening shut caught on fire. So if u put a battery in there...won't it like explode since it even has eletric in it?

 

[Frangible]

From what I've seen EMP is really overblown.

I was watching a video of a high altitude atmospheric nuclear test. (the kind that makes a big EMP)

It had a bunch of people sitting around on a beach in the pacific where they were testing it I assume, eating bbq, and a song was playing on a radio.

Then boom, the nuke explodes in the atmosphere, and creates a pretty light show.

The radio crackles and goes silent.

Then, about 15 seconds later, the radio starts playing again, and everyone resumes eating.

This was a government video restored in the DVD "Trinity and Beyond" and looked to be 1960-70ish.

Anyway, I wouldn't really worry about an EMP destroying all the electronics on earth or whatever like in fictional plots; I think the reality of the situation is quite different and your flashlight would be fine even if it were plastic.

 

[Eugene]

I think modern electronics are better as well. If you dig into the spec sheets of ny chip you see all kinds of protection, over voltage, over current, thermal shutdowns, short circuit protection, etc. For even the simplest of circuit say a Nand gate ot voltage regulator there are about a dozen extra ciruits for protection.

 

[tvodrd]

That would have been a vacuum tube radio. Vacuum tube technology has been long known to be more resistant to EMP. You should see some of the batteries portables used back then- seperate "cells" for the tube filiments and typically 45 or 90V for the B+. Automotive apps used a vibrator which rapidly turned on/off the 6 0r 12V into a transformer primary. The much higher secondary was rectified for the vacuum tube's cathode/plate voltage.

Larry

 

[E__WOK]

What good would a light be without someone to use it?

 

[bdillahu]

Thanks for all the answers... I was afraid this would be one of those "off the wall" questions that nobody could be bothered with.

Bruce

 

[Mednanu]

I have just one thing to say with regards to microwave ovens......


............... E g g s ..................


Loads of fun.......

 

[Rothrandir]

[ QUOTE ]
Mednanu said:
I have just one thing to say with regards to microwave ovens......


............... E g g s ..................


Loads of fun.......

[/ QUOTE ]

ut-oh..it's storee time!

[story]
back when i was a little dude, (around the age of 6ish maybe?) i complained to my mom that i was hungry. she said she could make some eggs, and i said "ok, i guess". mom pulled two eggs out, and made me a nice egg in the microwave. my egg was ok, so i didn't complain, though i wasn't particularly hungry for eggs.
she then inserts the second egg into the microwave, she takes it out, and it explodes as she bites into it.
i said "wow, that was cool!" i then looked down to my egg in dissapointment and said, "mom, can you please make me one like that?"
[/story]