Re: Coil size to faraday cage size ratio

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Stork" <rwall3264-at-bellsouth-dot-net> 

Finn,

It's essential to consider your OLTC broadcast frequency and mesh demension 
of the Faraday screen.  Think about the small mesh diameter holes and 
blocked  microwaves by glass fronts in microwave ovens.  It involves wave 
length vs hole diameter.  Anyone got the formula(e)?

RWW


Tesla list wrote:

>Original poster: "Finn Hammer" <f-h-at-c.dk>
>All,
>
>I`ve had my OLTC coil tested for EMI, and since it exceeds the legal limit 
>a 100 times, inside a faradays cage with 50db damping. This corresponds to 
>a 4Km (3miles)radius inside which the legal limit is violated.
>I am going to need a better cage.
>
>Question: For the same coil, will a big faraday cage offer better damping 
>than a small one.
>My reasoning says yes, since the longer distance to the cage, in the case 
>of a big cage, will result in a weaker field than as in a small cage.
>If the coil produces 600kV and the distance to the cage is 1meter in the 
>small cage and 2 meters in the big cage, then the small cage has to damp 
>from 600kV/meter, whereas the big cage only sees 300kV/meter.
>
>Is this correct?, and will it matter? If yes, by which factor 1/2? :-|
>1/4? :-\    1/16? ;-)
>
>Cheers, Finn Hammer
>
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