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StainlessSteelCynic
12-11-2009, 06:37 AM
While a friend and I were talking about Nikola Tesla he showed me a site on the web he had found that highlighted a massive Tesla coil in New Zealand.
http://atlasobscura.com/places/electrum

What really got my attention was the guy in the cage in the middle of all that lightning and the part of the article which stated that the man, a Mr Leyh, is safe inside a Faraday Cage. I had previously thought that Faraday Cages had to be sealed off from the outside but it seems that this is incorrect. The most important part to consider is the wavelength you are trying to protect against because you can have holes in the cage as long as they are smaller than the wavelegth of the EM radiation directed at it.

We did some checking on the net and found the following which gives a decent overview of Faraday Cages and how they work. I thought that some of you might be interested in respect to the protection from EMP that was discussed sometime back.

http://www.physlink.com/Education/AskExperts/ae176.cfm?CFID=23530784&CFTOKEN=838d8a91c2fb751d-7D923ECE-15C5-EE01-B9160999436E1DB5 a bit on the technical side
http://www.wisegeek.com/what-is-a-faraday-cage.htm short and to the point but page is loaded with adds
http://www.physics.gla.ac.uk/~kskeldon/PubSci/exhibits/E3/ interesting point about vehicles struck by lightning
http://www.juliantrubin.com/bigten/faradaycageexperiments.html some basics about Faraday himself and how it all works
http://www.amper.com.tr/eng/faraday_cage-140.htm turning a building into a Faraday Cage

Saving the best for last
http://www.jeddaniels.com/2007/faraday-cage-part-1/ this guy builds one to test WiFi signal protection
http://blog.makezine.com/archive/2007/06/tesla_faraday_cage.html I'm not sure I'd be brave enough to attempt this

kato13
12-11-2009, 07:02 AM
Thanks for the info I will be reviewing these today.

Here are the important threads on EMP we have had so far in case anyone wishes to review.

Vehicles and EMPs?
Faraday Cages

That Faraday cage thread is our second biggest draw for non gamers, after the post apoc pic thread. (Just discovered why. We are #1 for "homemade faraday cage").

Oh I have tweaked the Database to allow three character search again (it seems to revert on its own after any upgrade). Generally four character is the limit (to save database/cpu drain) but we are a small enough group that is not an issue for us. Given terms like TOE OOB and EMP are pretty important, let me know if it ever reverts back again.

Legbreaker
12-13-2009, 04:33 PM
The most important part to consider is the wavelength you are trying to protect against because you can have holes in the cage as long as they are smaller than the wavelegth of the EM radiation directed at it.
Absolutely spot on!
There's also a problem if you've got some sort of conductive material penetrating your "cage" such as electrical wiring.