EMP shield. Can you explain how it works?

[Realmaplesyrup]

How is an emp shield different than a surge protector. I see them advertised for cars as well. How would something that is not connected to the grid be protected from an emp?

 

[Just John]

EMP in the manner that I have heard it used as an acronym, stands for electromagnetic pulse. Magnetic waves going through a wire will generate a current, that is how a generator works. You don't have to be connected to the grid, just have a long enough wire.

 

[Realmaplesyrup]

I see. So it would just absorb it like normal.

 

[jasonhc73]

How about watch the youtube. A guy that sells them: youtube.com/watch?v=5xeiBMB5DiY

 

[Bvillebob]

EMP just stands for Electromagnetic Pulse. It's a short, sharp spike of electromagnetic energy across a broad spectrum of frequencies. The most common EMP experienced is caused by lightning. Lightning induces massive currents in power lines, which act as long antennae, the voltage induced can easily be high enough to jump across switches and destroy equipment plugged in and turned off.

EMP is also used as a boogieman to sell stuff to worried people. The common story is that a nuclear weapon exploded in the upper atmosphere can cause a destructive power surge across a large area. The effects are often highly exaggerated for fear porn and marketing purposes. The amount of power induced in a device is proportional to the size of the antenna / power cord attached to the device. For example, an unplugged laptop sitting on your desk wouldn't be affected, a desktop plugged into the wall could well be destroyed, just as with a lightning strike. The idea that all cars would quit working, radios would all be dead, cellphones wiped out, etc. is just silly but makes for lots of knockoff books about TEOTWAWKI.

I used to spend a lot of time and money installing equipment to protect communications infrastructure, it's not hard to do with some planning, the equipment needed is widely available. I used to visit antenna arrays that literally had corona discharge dancing off the ends of the elements, 100's of 1,000's of volts of potential ionizing the air into a glowing plasma caused by static buildup around thunderstorms in the high desert, yet none of the electronics were damaged and just kept functioning year after. year.

 

[jasonhc73]

15 Minute Main switch "off to on" for this install.

 

[The Dish Doc]

I'm skeptical that the device works

 

[Supervstech]

Looks like a common surge protection device.
Can absorb some range of spikes...

 

[Risky Rob]

The only phenomenon that could spell doom would be a huge pulse from the sun. In 1859 there was one. I would guess solar panels, controllers, smart batteries would suffer.

 

[Supervstech]

Idk, a pulse from a large atomic device could be.troublesome...
Certainly a Carrington event striking today could cause mayhem...
Any unshielded wire or device connected to unshielded wire would suffer...

 

[Risky Rob]

Idk, a pulse from a large atomic device could be.troublesome...
Certainly a Carrington event striking today could cause mayhem...
Any unshielded wire or device connected to unshielded wire would suffer...

How would a wire or device be shielded? A Faraday cage?

 

[JRH]

EMP just stands for Electromagnetic Pulse. It's a short, sharp spike of electromagnetic energy across a broad spectrum of frequencies. The most common EMP experienced is caused by lightning. Lightning induces massive currents in power lines, which act as long antennae, the voltage induced can easily be high enough to jump across switches and destroy equipment plugged in and turned off.

EMP is also used as a boogieman to sell stuff to worried people. The common story is that a nuclear weapon exploded in the upper atmosphere can cause a destructive power surge across a large area. The effects are often highly exaggerated for fear porn and marketing purposes. The amount of power induced in a device is proportional to the size of the antenna / power cord attached to the device. For example, an unplugged laptop sitting on your desk wouldn't be affected, a desktop plugged into the wall could well be destroyed, just as with a lightning strike. The idea that all cars would quit working, radios would all be dead, cellphones wiped out, etc. is just silly but makes for lots of knockoff books about TEOTWAWKI.

I used to spend a lot of time and money installing equipment to protect communications infrastructure, it's not hard to do with some planning, the equipment needed is widely available. I used to visit antenna arrays that literally had corona discharge dancing off the ends of the elements, 100's of 1,000's of volts of potential ionizing the air into a glowing plasma caused by static buildup around thunderstorms in the high desert, yet none of the electronics were damaged and just kept functioning year after. year.

I have seen that phenomenon on the tip of my 45 ft sailboat mast in a storm at sea at night.Its not cool to see while hanging on to a stainless steel helm which is bonded to the mast a few ft away.. its right scary… but I’ve never heard of it hurting anyone. But I don’t know …..its been along time but I remember it being called St Elmo’s fire… but I may be wrong , I’m getting old..

 

[Supervstech]

How would a wire or device be shielded? A Faraday cage?

I’m not the one to know this. But cables sheathed in a grounded conductor should do it, as would a faraday cage around a device.

 

[Warpspeed]

Its pretty well impossible to protect most things from an EMP.
People have no idea how powerful these things are.

Its like looking at an automotive spark plug and saying a direct hit from a lightning bolt is really just like a spark plug, but bigger.

Just like a themonuclear explosion is just like a fire cracker, but bigger.

So just fit this little gizmo to all your expensive electronics and you will be fully protected.
Quite funny actually.

 

[Risky Rob]

Its pretty well impossible to protect most things from an EMP.
People have no idea how powerful these things are.

Its like looking at an automotive spark plug and saying a direct hit from a lightning bolt is really just like a spark plug, but bigger.

Just like a themonuclear explosion is just like a fire cracker, but bigger.

So just fit this little gizmo to all your expensive electronics and you will be fully protected.
Quite funny actually.

So a man-made emp is incredibly powerful and destructive?

 

[Warpspeed]

Yes indeed it is.
The electrical energy comes directly from a nuclear blast, and the electrical and magnetic fields produced are almost beyond imagination in thier power, just as the heat and blast energy is.

A specific EMP weapon is much more efficient in producing the electrical effects than blast effect.
But just about anything with transistors or semiconductors will be totally destroyed in function.

A bit of tinfoil or sheet metal is no protection from any of these effects.

 

[Risky Rob]

Yes indeed it is.
The electrical energy comes directly from a nuclear blast, and the electrical and magnetic fields produced are almost beyond imagination in thier power, just as the heat and blast energy is.

A specific EMP weapon is much more efficient in producing the electrical effects than blast effect.
But just about anything with transistors or semiconductors will be totally destroyed in function.

A bit of tinfoil or sheet metal is no protection from any of these effects.

I did a little research on what are called e-bombs. Non nuclear pulse weapons.

 

[Warpspeed]

Yes, non nuclear EMP weapons have been around since the late 1950's.
A very fast explosive, a magnetic flux compression device, and a high powered microwave generator and wide band antenna.
Apparently its all come a very long way since then.

 

[rogerdw]

A bit of tinfoil or sheet metal is no protection from any of these effects.

I've been invited to a bbq tonight and apparently the invitee wants help with a faraday 'box'.

I can understand a faraday cage style cover for a mobile phone for example, preventing it from communicating or transmitting its location ... but have no clue about the idea of protecting electronics against an EMP weapon.

I get that you're saying that basic tinfoil and sheetmetal covers or boxes offer no protection ... but do you think there are any measures people can take ... or is it simply an electronic version of 'put your head between your knees and kiss your backside goodbye'.

For some reason I wondered about a solid metal box buried underground, or would it need to be fifty feet down to stand a chance.

 

[Warpspeed]

Put it this way.
A Faraday shield needs to be a completely enclosing cover without any gaps, slots, holes, or cable entries.
That will work fine preventing a mobile phone from transmitting its location.

But it only attenuates an EMP weapon by some measurable amount, not total elimination.
A fully screened room is certainly possible, but without cable entries or ventilation is not really practical for anything.

A solid metal box buried deep would be excellent, but how would you use that exactly ?
Under salt water in a submerged submarine would be even better, or down very deep in a mine perhaps.

The way I see EMP weapons being used, you first zap an enemy.
Then you wait a couple of weeks for the enemy to repair whatever he can, using up all his spare parts.
Then you zap him a second time, and he is done....

So hiding your computers, ham radio gear and such underground might be possible, but you will never know if you are going to get zapped again several times. The reality is, there is not much you can really do if a serious full on war breaks out, and EMP is only one of a whole bunch of problems everyone will face.