Trent W. Buck wrote:
Rohan McLeod wrote:
I am investigating making a flexible faraday-cage for my mobile phone; I don't have experience myself, but everyone seems to be doing it. I presume you already tried these: Thanks I was actually just looking for fabric with a conductive coating; it is many years since I dropped out of Electrical Engineering; but enough must have penetrated to register, that there seems to be much confusion out there !
The Wikipedia article seems to have basically the right idea; it starts with static charges in hollow conductors; then talks about static charges in earthed hollow conductors. My take on the AC shielding effect is: A spacial oscillation of the charge would produce a spacial oscillation of it's electrostatic field; but since the voltage on the outside of the hollow conductor, must be everywhere the same with respect to earth and zero if it is earthed; no evidence of it's oscillation is transmitted beyond the enclosing conductor. It would have been useful to have the analytical expression for the ratio of the intensities of a pure sinusoidal electromagnetic wave of frequency 'f '; inside and outside a conducting sphere with a single hole of dia, 'D'. Seems to be ~ k.(2.pi.f.D)^6, but there is no derivation
They seem very confused at duckduckgo; the essential problem seems to be the transparency of faraday-cages to static magnetic fields; but their known opacity to EM radiation.The simple explanation seems to be that one only needs to attenuate one component ; in this case the electric field to attenuate the EM radiation thanks Rohan McLeod