# Flashlights vs EMP Electro Magnetic Pulse



## bluemax_1 (Jun 5, 2013)

A curious question popped into my head: What flashlight designs would most likely still be usable after an EMP event?

- old school direct drive incandescent?
- dual circuitry LED (like ArmyTek's Predator Pro)?

As we all know, a nuclear device will set off a powerful EMP, but these days, there are also devices developed specifically to trigger an EMP, and a friend of mine claims that a power pole transformer/junction box blowing up ~30 feet away from him triggered an EMP that killed his Casio watch (not to mentioned scaring the heck out of him).

Any ideas? I even recall someone mentioning that they have their SHTF flashlights stashed in a Faraday cage for just such a reason.

- is there anything about an LED that might make it inherently more susceptible than an incandescent bulb?
- does it matter if there are batteries in the light or if it's On vs Off? AFAIK, most electronics are most vulnerable when they're powered (unless specifically shielded against EMP).
- how vulnerable are spare batteries?


Max


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## AnAppleSnail (Jun 5, 2013)

Google'd it, Site:CPF.org EMP to find: 
If the EMP is strong enough to kill your light, you're probably just prolonging the inevitable unless you already live on a farm with seed re-use, twenty armed men, and a bullet-loading press. Very few people have test rigs that really check for the effects of a large-scale EMP event. Smaller test rigs can be made, and guesses can be made. This is complicated because an EMP is a multistage event.

Edit: I believe that I have killed flashlights with static discharges. This is certainly different from an EMP, but then I spend time in 200kV static fields, not powerful,l changing magnetic effects.


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## Cereal_Killer (Jun 6, 2013)

There's no excuses not to have a faraday cage in every home with a few basic electronic dvices (a couple good lights, weather radio and walkie talkie/ HAM/longer range radio equipment) you can purchase these hi-tech faraday cages at any army surplus / camping/outdoor stores for about $12, there called ammo cans (or any other tightly sealed metal box would work too, trash cans, coffee cans with a metal lid, any metal box will do)


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## The_Driver (Jun 6, 2013)

The HDS lights (at least the legacy clickies) are supposed to be EMP proof. If you're trying to convince someone to get one and nothing has worked: mention this .


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## StarHalo (Jun 6, 2013)

There's at least a dozen lengthy threads on this topic, be sure to search for plenty of reading. Some highlights:

- An ICBM attack may include an EMP-specific stage where a warhead is detonated ~120 miles over the target area; there would be no blast/heat/radioactive damage, but it would blackout multiple states underneath the detonation. This means you may still be subject to an EMP attack even if you live nowhere near where an actual nuclear blast occurs. 

- A microwave, if grounded, is an excellent Faraday cage.

- Roughly two-thirds of cars will survive an EMP attack.

etc.


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## JCD (Jun 6, 2013)

Wouldn't most flashlight bodies serve as Faraday cages for enclosed electronics?


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## AnAppleSnail (Jun 6, 2013)

JCD said:


> Wouldn't most flashlight bodies serve as Faraday cages for enclosed electronics?



It depends on several things, including geometry of the 'conductive shell.' Radio Frequency shielding is sensitive to penetration size. In some cases, the shell with a small hole will have a concentrated field in some areas. I do not know if the hole in the aluminum reflector will concentrate magnetic fields through the LED and circuitry there.


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## ragweed (Jun 6, 2013)

I have the ammo cans!


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## AVService (Jun 6, 2013)

ragweed said:


> I have the ammo cans!



Me too but where will my ammo go?


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## fyrstormer (Jun 6, 2013)

Cereal_Killer said:


> There's no excuses not to have a faraday cage in every home with a few basic electronic dvices (a couple good lights, weather radio and walkie talkie/ HAM/longer range radio equipment) you can purchase these hi-tech faraday cages at any army surplus / camping/outdoor stores for about $12, there called ammo cans (or any other tightly sealed metal box would work too, trash cans, coffee cans with a metal lid, any metal box will do)


You can buy a fire safe and kill several birds with one stone. But the thing AnAppleSnail quoted is pretty much spot-on: unless you have the equipment to survive in a place like Somalia, you're not going to be better-off than your neighbors for long.


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## braddy (Jun 6, 2013)

Being able to last 12 months or 18 months, sure goes a long way towards getting past whatever the first period or two, or three, offers.


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## Poppy (Jun 6, 2013)

I keep my small transistor radio in a mylar bag. I read somewhere that that is an effective means to protect it from an EMP. It is also encased in a cardboard-like sheath, insulating it from actually touching the bag. I don't know why that is there. Is it something that I read? I don't recall.

Last year a PBS station aired a few worst case scenario survival situations. One of them being a nuclear dirty bomb blast. They mentioned that cars that were running at the time would be toast, but those that were not running would be OK. The survivor selected a diesel powered SUV for his vehicle, and ran it on cooking oil. 

Newer diesels are computer controlled just as their gasoline counter parts are. The computers of cars and trucks have a small amount of current supplied to them at all times for "KAM... Keep Alive Memory". Did they miss that fact? Or does it NOT matter? 

If it doesn't matter, then I imagine that flashlights that have a slight parasitic drain are not more suseptible to damage than others. OTOH, if it does matter, then I suspect that lights with "memory" may be more likely to be damaged.

One thing for sure... a zippo lighter, and candles won't be affected. :thumbsup:


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## JJohn (Jun 6, 2013)

The_Driver said:


> The HDS lights (at least the legacy clickies) are supposed to be EMP proof. If you're trying to convince someone to get one and nothing has worked: mention this .



I find this hard to believe. Unless they use a metalized, conductive, front crystal. The LED itself will not be able to handle the E-fields from a large EMP. I fully believe the head and tube could act as a Faraday cage and protect the electronics. But the emitter, I think it would be vulnerable depending on its orientation to the field.


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## bluemax_1 (Jun 6, 2013)

Lots of interesting replies. I also didn't realize there were numerous other threads about flashlights and EMPs. Looks like I have quite a bit of interesting reading material.


Max


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## StarHalo (Jun 6, 2013)

Poppy said:


> a nuclear dirty bomb blast.



Much more likely than an EMP attack, and much more difficult to prepare for. A dirty bomb is some radioactive material included with an explosive, there's no EMP, just radiation. Much cheaper and easier to put together than an actual nuclear weapon.

Regarding cars and EMP: Modern cars' engine electronics are well-shielded, where they are vulnerable are various ancillary electronics, like the gauges, displays, indicator lights, etc. Almost all modern cars exposed to a strong EMP will have some malfunctions on the dashboard, but will still run.


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## riccardo (Jun 7, 2013)

> Almost all modern cars exposed to a strong EMP will have some malfunctions on the dashboard, but will still run.



I'm not so sure, it depends on how the ECU will act once it detect a malfunction on external sensors/accessory circuits. It's hard to judge since it depend on the ECU's program.
Moreover, there might be some unshielded wiring that in a really strong EMP event will pick up some strong transitory frying sensors or ECU.

But I'm sure on one thing: in the old Europe at least the old Citroen Saxo 1.5 diesel will keep on working. It's a very small hatchback equipped with a very old kind of naturally aspirated diesel with mechanical injection. Basically almost an old style tractor engine capable of a decent 60 HP.

Once I had an interesting experience, I was driving one of this little car (was my parent's second family car) on an unpaved road at night in a wood when I hit the bottom of the engine bay on a big stone, it happen that the alternator belt got loose (the alternator bracket was bended) and the alternator stopped. I was left only with the car's battery running all the electrical stuff (electric power-steering included), I had to keep on driving.. when the battery got flat I was without driving lights, without power-steering (luckily in case of malfunction electrical ones are not getting so hard like hydraulic ones does) and without all electric devices (windows, spedometer, rev counter.. everything was dead), but the car was keeping running fine.

Than I did a mistake and stalled the engine.. since it was still hot, with the help of two friend, we pushed the car in 3rd gear and it started again without problems!!


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## Tactika (Jun 7, 2013)

Faraday bags (similar to the ones used to protect several computer parts) are easily findable on the Internet, and are cheap. I think it's a good idea to keep several electronic devices, such as flashlights and survival radios, inside an EMP/Faraday bag, stocking it somewhere in the house, just in case.

Yet, I also wonder if the body of most aluminum flashlight does protect it against moderate EMP.


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## braddy (Jun 7, 2013)

While it is fine to store our disliked unused flashlights in faraday cages, and I'm trying to do that, the real focus of this discussion to me, is what about our best, top of the line flashlights and beloved EDC lights, our blackout lights on the shelves, in other words the lights that are not stored in faraday cages and the ones we would most want in an emergency.

I would like to hear more focus purely on the question of whether our led flashlights can be depended on being usable after an EMP, will my Fenix AA lights still be operating?


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## AnAppleSnail (Jun 7, 2013)

braddy said:


> Will my Fenix AA lights still be operating?



This is sort of like asking if a pot will burn your fingers when you pick it up. In broad strokes, it will depend on the EMP and your relative location. In particular, it seems to be difficult to do so. Contact one of several qualified EMP simulation agencies and submit a few flashlights. We'd love to find out, but nobody seems to have published such a test from a credible tester.


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## JCD (Jun 7, 2013)

braddy said:


> While it is fine to store our disliked unused flashlights in faraday cages, and I'm trying to do that, the real focus of this discussion to me, is what about our best, top of the line flashlights and beloved EDC lights, our blackout lights on the shelves, in other words the lights that are not stored in faraday cages and the ones we would most want in an emergency.
> 
> I would like to hear more focus purely on the question of whether our led flashlights can be depended on being usable after an EMP, will my Fenix AA lights still be operating?



As has been pointed out, the emitter will be vulnerable in almost every LED light, since it is exposed. Depending on switch design, the light's regulator and the protective circuits for the cells would probably be protected by the flashlight case. If you're seriously concerned about EMP and don't want to use a Faraday cage or pouch, then storing your light bezel down on a metal shelf will improve the odds it survives an EMP, provided there is enough metal in the switch(es) to work as a Faraday cage.


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## fyrstormer (Jun 9, 2013)

braddy said:


> While it is fine to store our disliked unused flashlights in faraday cages, and I'm trying to do that, the real focus of this discussion to me, is what about our best, top of the line flashlights and beloved EDC lights, our blackout lights on the shelves, in other words the lights that are not stored in faraday cages and the ones we would most want in an emergency.
> 
> I would like to hear more focus purely on the question of whether our led flashlights can be depended on being usable after an EMP, will my Fenix AA lights still be operating?


I have spares of my favorite flashlights in my fire safe, in case I lose the ones I carry with me, and to keep them from being stolen. I suppose they would also be protected against EMP, assuming I survive the explosion.


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## kengps (Jun 9, 2013)

fyrstormer said:


> I have spares of my favorite flashlights in my fire safe, in case I lose the ones I carry with me, and to keep them from being stolen. I suppose they would also be protected against EMP, assuming I survive the explosion.



An EMP attack would not produce a killer explosion. Read the Federal Governments EMP commission report. It is a very long read, be warned. It details about every system in the USA. I learned a lot about how the US works and runs. It basically says one atomic device detonated at an altitude of 250 miles over the central USA would wipe out the electronics in 80% of the USA land area. The electric grid, communications, internet, pipeline systems, Banking, money, all gone. The possibility of resuming life as we know it would take years, if ever. Just about everything is controlled by electronic sensors and switches these days. BTW, they did say most cars will continue to run. Getting fuel for them is the problem when the economy stops.

Some solar chargers, batteries, and efficient LED lights with long runtime would sure be a luxury. Put some in an ammo can, along with a solar/crank radio.

Here's some EMP Commission trivia for you.....The USA Electric grid consist of the West Intertie, East Intertie, and Texas.

Also, a very powerful solar storm could damage the electric grid. Replacing the largest transformers would take years. about the same outcome as an EMP attack.


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## Philip2 (Jun 15, 2013)

Wrapping a survival radio in aluminum foil, may IMO protect it from EMP. 

In a survival radio a low power flashlight, handcrank and solar panel should be integrated.

In a disaster situation you might have to evacuate without a motor vehicle, with a backpack, bicycle, inflatable rowing boat or small cart. 

If your batteries run dead, or your your flashlight would crash for whatever reason, you could rely on a handcrank/solar backup flashlight or candle. Or on an improvised oil lamp with a improvised wick, that runs on fat or vegetable oil. 

Or we could sleep and wait till the sun comes up, as our ancesters have done for hundred thousands of years.


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## bluemax_1 (Jun 16, 2013)

Philip2 said:


> Wrapping a survival radio in aluminum foil, may IMO protect it from EMP.
> 
> In a survival radio a low power flashlight, handcrank and solar panel should be integrated.
> 
> ...


While the concept of a hand crank radio/flashlight sounds great for preparedness, does anyone know of any really reliable units that can be run for a decent amount of time and used continually without some sort of failure? If so, could you post up the brand and model?

All the ones I've seen or used apparently aren't made for serious use (eg. 5-minutes of cranking for 15-20 minutes of use. Or 5-minutes of cranking for 1-2 hours of use, but it doesn't work for more than 10 uses before breaking).


Max


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## Poppy (Jun 16, 2013)

riccardo said:


> I'm not so sure, it depends on how the ECU will act once it detect a malfunction on external sensors/accessory circuits. It's hard to judge since it depend on the ECU's program.
> Moreover, there might be some unshielded wiring that in a really strong EMP event will pick up some strong transitory frying sensors or ECU.
> 
> <snip>



The crankshaft position sensor, and the camshaft position sensors are absolutley needed, or the engine won't run, I'm thinking that most of the other sensors if fried, can be unplugged, and if the ignition system is still intact, then it should run. The PCM will have stored values for those disconnected sensors, and will just run the engine based on them... essentially running blindly.


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## mattheww50 (Jun 16, 2013)

AnAppleSnail said:


> Google'd it, Site:CPF.org EMP to find:
> If the EMP is strong enough to kill your light, you're probably just prolonging the inevitable unless you already live on a farm with seed re-use, twenty armed men, and a bullet-loading press. Very few people have test rigs that really check for the effects of a large-scale EMP event. Smaller test rigs can be made, and guesses can be made. This is complicated because an EMP is a multistage event.
> 
> Edit: I believe that I have killed flashlights with static discharges. This is certainly different from an EMP, but then I spend time in 200kV static fields, not powerful,l changing magnetic effects.



Most small electrical/electronic devices are likely to survive an EMP attack virtually unscathed. EMP damage depends upon producing large induced voltages in devices. The longer the wires that are attached, the more energy that can be delivered. This is why the power grid and telephone network (pre-fiber optic) are so vulnerable. Miles and miles of cable= enormous induced voltages. The voltages you can induce when we are only talking about a few centimeters of wire are small even in the presence of very strong fields.

We actually do have pretty good data about large EMP events. I suspect most of it is classified. We inadventently created one in the early 1960's with a Nuclear Weapons test that did considerable damage to parts of Hawaii. Of course it wasn't recognized as EMP damage until long after the fact.

IN any event, a Flashlight typically has pretty short wiring runs, particular the portions outside the body, which is essentially a Faraday cage. As a result it is very difficult to come up with scenarios where the induced voltages would be sufficient to cause damage at Field strength's that would not also do great damage to the human body.


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## AnAppleSnail (Jun 16, 2013)

The hole in the conductive shell can (under tricky-to-define) certain conditions of frequency and orientation, concentrate the effects inside the shell. Penetrations in faraday cages require careful design to mitigate this effect. Of course, the shell of a flashlight is a pretty small collector.


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## Philip2 (Jun 17, 2013)

bluemax_1 said:


> While the concept of a hand crank radio/flashlight sounds great for preparedness, does anyone know of any really reliable units that can be run for a decent amount of time and used continually without some sort of failure? If so, could you post up the brand and model?
> 
> All the ones I've seen or used apparently aren't made for serious use (eg. 5-minutes of cranking for 15-20 minutes of use. Or 5-minutes of cranking for 1-2 hours of use, but it doesn't work for more than 10 uses before breaking).


Google: "hand crank" solar charge radio review 2013


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## StarHalo (Jun 17, 2013)

Philip2 said:


> Google: "hand crank" solar charge radio review 2013



Just head over to CPF's radio thread.


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## MichaelW (Jun 18, 2013)

I accidently contacted two live contacts in the Edison base of the close light socket. The screwdriver tip melted in a nice bright spark. [I was tightening loose contacts]
I was streaming audio to the computer, and the router, which is 10 feet away (in 3d measurement, and through 4 layers of drywall-if that has any attenuation properties?), just stopped working.
I had to unplug/re-plug, lucky for my wallet, it worked.

So for WW3, I imagine the Russians will attempt a simultaneous, or near simultaneous exo-atmospheric detonation of their biggest EMP device, ~200 miles up over Salt Lake City, Utah & Indianapolis, Indiana.
That gets everybody, and the middle strip: ND, SD, NB, KS, OK, TX twice, but at a slightly lower intensity.
If you are in Alaska & Hawaii, well, you had better already be self-sufficient before the party starts.


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## bluemax_1 (Jun 18, 2013)

Philip2 said:


> Google: "hand crank" solar charge radio review 2013





StarHalo said:


> Just head over to CPF's radio thread.



Thanks. Checked out several of those and many (most?) have very mixed reviews. I might give the Ambient Weather 111B a shot.


Max


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## StarHalo (Jun 18, 2013)

bluemax_1 said:


> I might give the Ambient Weather 111B a shot.



That particular model is a good design with the exception of its digital display - this kind of display drains the battery just to show you time/tune info, more so with backlighting. I would recommend instead the CCrane CC Solar Observer, which has the same features but an analog display, so the battery goes only towards audibly operating the radio, giving you notably better battery life. It works so well that the CC Solar can operate with no battery whatsoever; even with its internal battery disconnected/destroyed, it can continue live radio playback on sunlight alone - digital radios need too much current to pull this off.


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## Sub_Umbra (Jun 18, 2013)

If one goes through an EMP event big enough to shut down something as small as a flashlight, _flashlights will be the very least of one's problems..._


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## Paladin (Jun 18, 2013)

For a well written but fictional novel regarding how an EMP might effect society, read "One Second After" by Willian R. Forstchen. Type 1 Diabetics, you won't be around long enough to starve. Paladin


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## idleprocess (Jun 18, 2013)

Opinions on this subject are certainly mixed. I suspect that, short of having prepared for and indeed be _presently living_ the post-disaster lifestyle in a self-sufficient fashion, preparing for it is somewhat futile.

Nuclear weapons produce EMP's by their nature, but they're not the only source of destructive EMP's. There are plenty of non-nuclear designs for broad area-of-effect weapons - with the explosively-pumped flux compression generator arguably being the oldest, best known - _and likely least potent_. In the event of a major event where EMP's are used, I would not be surprised if waves of these devices are deployed so as to destroy backup equipment deployed after each strike.

Boeing recently demonstrated a missile-like munition (perhaps it was a reusable drone) capable of transmitting a directed pulse over an area that destroyed most electronics targeted (as well as the monitoring equipment). I know that there numerous plans for _electronic disruptors_ (essentially focused microwave transmitters) varying from handheld to truck-sized that wreak havoc on devices within range.

Keeping flashlights, radios, small solar panels, hand-crank generators, batteries, whatnot in small faraday cages such as ammunition cans, altoid tins, whatnot might keep them alive until after it's all over, but with the industrial economy thoroughly and irreparably broken, it will be the dying embers of the industrial age as you are thrust into mid-19th century technology without the benefit of a working mid 19th-century society.


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## idleprocess (Jun 18, 2013)

mattheww50 said:


> The longer the wires that are attached, the more energy that can be delivered. This is why the power grid and telephone network (pre-fiber optic) are so vulnerable. Miles and miles of cable= enormous induced voltages.



While the fibers themselves in a fiber-optic network will be unaffected by a massive EMP event (as opposed to the arcing/breaking in copper cables / cross-connect boxes), odds are every bit of active equipment connected to it that makes the network function is connected to some sort of electrical grid that will merrily fry all them.


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## Norman (Jun 19, 2013)

idleprocess said:


> Boeing recently demonstrated a missile-like munition (perhaps it was a reusable drone) capable of transmitting a directed pulse over an area that destroyed most electronics targeted (as well as the monitoring equipment).



Ah, you must be referring to Boeing's Counter-electronics High-powered Microwave Advanced Missile Project (CHAMP) system. Basically, it's an EMP generator mounted on a (cruise) missile. It can fly around firing EMP bursts over multiple targets.

Video here
http://www.boeing.com/Features/2012/10/bds_champ_10_22_12.html
or, apparently, here
http://news.discovery.com/tech/champ-drone-emp-121026.html


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