Posted on 04/10/2013 6:45:54 AM PDT by Mr. K
The reality of protecting all electronic equipment against EMP from a nuclear explosion over our shores is becoming imminent. We now live in perilous times.
The information to follow on building "Faraday cages" is timely indeed. A single atmospheric nuclear detonation releases enough electromagnetic pulse (EMP) to equal 100,000 volts per square centimeter on the ground. A single detonation 200 to 400 miles over the center of the continental United States would fry every unprotected computer chip from coast to coast, and from the middle of Canada to the middle of Mexico. And we are now into Solar Cycle 23, with solar flares common and expected to continue until the first of next year. CME's are capable of extreme damage to modern computerized equipment! Sure, we have our windup BayGen radio's and spare lap top computers, but unless electronic equipment is protected from an electromagnetic pulse, they will be fried!
When Einstein and the others first refined and purified uranium, they took time off and studied its properties. That is when they discovered the "rays" that were harmful, as well as the phase transformations. In the course of their work, one of the scientists discovered that simply covering an object with a grounded copper mesh would stop virtually all electromagnetic radiation, whether proton or neutron. Obviously, they had to protect their monitoring equipment! Thus was born the "Faraday cage."
The copper mesh, like 1 inch chicken wire, worked well in large uses, like covering buildings, and it is still in use today: FEMA headquarters buildings are dome-shaped earth-bermed structures, and under the earth is a copper mesh that extends out from the base and is secured by grounding rods.
As an Electro Magnetic Pulse (EMP) travels to earth, whether from a Coronal Mass Ejection (CME) or a nuclear detonation in the atmosphere, it hits and runs along electrical power lines as well, building up voltage and amperage, which is what happened during the last solar storm a dozen years ago, blowing out transformers and leaving 6 million people in eastern Canada without power for weeks.
To prevent that problem, if you have a hard-wired generator, the wiring from the generator to the house should run in conduit that is grounded. The generator itself can have the frame grounded for added insurance, but that ground wire MUST be insulated and run to a different ground rod well away from the ground rod for building and conduit!
With radio's and smaller appliances, a Faraday cage can be built by using two cardboard boxes: one should fit tightly inside the other, and the item to be covered should itself fit reasonably well inside the smaller box. That is about the most work involved--finding the right size boxes! The outer box is then covered with aluminum foil or Mylar, as from a cheap "space blanket." A grounding wire is then taped to the foil. I then cover the foil with black 6 mil plastic, taped securely in place, to protect the foil from ripping. At the end of the ground wire I attach a cheap small alligator clip from Radio Shack. The item to be protected is placed inside the inner box, which acts as insulation from the outer box, and any EMP hitting the foil and is bled away by the ground wire.
Some medium sized electrical equipment can also easily fit into boxes covered with foil for EMP protection. My laptop computer, for example, fits easily into a Faraday box made from a box that held reams of paper: the entire lid is removable, allowing easy access to the laptop in its case, but is safely stored when not in use.
For larger items which cannot be boxed, such as living room TV sets, etc, I tape a Mylar space blanket to a piece of 6 mil black plastic sheet, using double-sticky tape every foot or so to make sure the Mylar stays in place (it is slippery). I leave a 2 inch edge of black plastic showing all around the space blanket, and while taping down the edges I put on a short lead of ground wire. When it appears that EMP or CME's are on the way, the blanket can be draped over the appliance, the alligator clip attached to a small, unobtrusive ground wire behind the cabinet, and any electromagnetic radiation will be diverted to the ground wire. Very cheap, simple, and once done, items can be "draped" for protection very quickly indeed. And the plastic blankets fold up neatly for storage, ready for use when needed.
The time to build Faraday cages or blankets is NOW, as when they are actually needed it will be far too late. Each box should be labeled on the ends and the top for the exact appliance they were built for, to eliminate any confusion when they must be protected in a hurry. Any electrical appliances not in use should be stored in the Faraday cage, where they will be kept clean, neat, in a known location, and protected against any sudden EMP surge.
“So...whaddya got?”
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The cage itself will have a (voltage) potential from one location to another (on the cage), which is why inside the cage is electrically silent. The carboard is an insulator between the goods you want to protect, and the conductive cage.
Grounding the cage is unnecessary.
” I do think it makes sense to have rechargeable batteries, a solar system to provide some basic recharge system, a solar water pump, etc.”
Solar cells are huge semiconductors with a P/N junction similar to a diode and would be the first thing to go if they were on your roof.
“space blanket.”
I might start buying them again just for this.
They make lousy blankets.
My 67 Chevy should still run, but of course all the gas pumps are now fully electronic so I’m still hosed....
“What I don’t understand is the logic of trying to protect a generator that will require fuel which will quickly become unavailable following any event that takes out major power distribution facilities, transformers, etc.”
If it’s a diesel generator, then you can probably run it on biodiesel, or even ethanol, that you could produce yourself. That will probably lessen the lifetime of the generator, but it’s better than no power at all.
We have a 4 drawer metal filing cabinet which we plan to use as a faraday cage. It will work just fine as will a metal 30 gallon trash can. Also if your car is in the garage and you ground it with a piece of chain or something hanging off the bumper chances are it will start again after an EMP.
Conduit comes in aluminum, steel (RGS), and plastic.
The Faraday cage works on the principal (discovered by Faraday), that an electric field inside of a conductor will always be zero because the electrons inside the metal always move in such a way as to always cancel the external field.
I realized after I posted that copper mesh is an effective Faraday cage, so the magnetic field alone must not be an issue. Thanks for information.
“I dont think so- I think Aluminum is a good conductor”
Aluminum foil acts as a farday cage. Ex: Turn off your cell phone and wrap it in aluminum foil and it will survive an EMP. Paper a closet with aluminum foil top to bottom and it becomes a faraday cage.
We have had three EMP solar strikes since the late 1800’s. Cover your gen’s with foil. Try using the original box, if possible. Use tape to secure the edges. Learn to protect your fuel source, by being a bit smart. Energy will be your main concern- after water storage and food storage. Get the clue. It is not that hard to prep, just a bit.
“The bomb releases a magnetic pulse that is NOT electrical.”
This is not correct. EMP stands for electro magnetic pulse. Electric pulses do not propagate by themselves and neither do magnetic pulses. Combined, the wave travels at the speed of light in a vacuum. Spark a wire across a battery and you will hear it on an AM radio. That’s the kind of pulse were talking about, only millions of time larger.
“Aluminum foil acts as a farday cage. “
How about my Airstream travel trailer?
You know, for an article that purports to be authoritative, it has the wrong units for electric field. It makes you wonder what else is wrong. Probably a lot.
It's volts per meter, not volts per square area.
I suspect these people are just copying and pasting stuff, and know nothing about actual RF engineering. This is my field.
This is not even coherent enough to be wrong. It is virtually meaningless, like something sent repeatedly through "Google Translate."
Regards,
I suspect the roll-type radiant barrier material would help protect electronic gear inside houses, too - at least the stuff that's not plugged-in to power outlets or antennas. I know it'll block RF well enough to silence an attic-mounted shortwave antenna.
We put a motorola reserve charge/battery pack for my kids tablets in our tornado room and it allows the kids to play their games (and remain calm) when the power is out. Have had to use it once and am glad we had it.
Entertainment for kids is often overlooked.
My problem is that even if I prep well, I am dependent on hormone replacement drugs to live due to cancer surgery. My life expectancy is about 30 days after I take the last pill. Unfortunately the government will not permit me to obtain more than a 30 day supply on a refill because this medicine is abused by trainers and athletes. Therefore, if we have an EMP attack, and services are not restored quickly (which they won’t be), I’ll certainly be a casualty.
You don’t know what you’re talking about.
You haven’t built a ‘Faraday cage’. You have built a shielded enclosure.
Click on name for further info ..
I had a solar panel to provide trickle charge to my boat battery. Lighting strike caused diod to blow and actually melted leads where they connected. No other damage to electrical systems. Always wondered if the charge from the strike did it, or if the flash was so bright it generated a spike of current from the panel that caused it. Replaced the diod and all was well.
If I had panels for SHTF, I think I would try to protect them and not mount them till after the event.
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