BigJohn1
Electrical
- May 24, 2003
- 57
I'm trying to understand how a faraday cage actually serves to provide electromagnetic shielding.
What I've read seems to suggest that a true "Faraday cage" is a mechanism that only applies to electrostatic charges; as best as I understand it the charges applied "cage" are distributed equally along the outer surface, which creates a uniform electric field, these fields somehow cancel each other. Though, I'm not sure about that because it seems to me that theory would be strongly dependant on the actual shape of the cage...
If a true Faraday cage does only applies to electrostatics, then what is taking place inside say, an automobile struck by lightning or shield providing protection from RF radiation? Those devices are subject to changing electrical fields, what keeps those fields from propigating inside the respective car/shield? I'm leaning towards what I understand about the skin effect, is that the right track? Would the car/shield be analogous to a solid conductor? If the shield in question is not made up of solid sheets of metal, but rather is an actual cage of conductors, would my best bet be examining the parallel current flow through the respective conductors?
I'm having a lot of difficulty finding straight answers on this, any help would be greatly appreciated. Feel free to throw in any pertinent equations.
Thanks.
-John
What I've read seems to suggest that a true "Faraday cage" is a mechanism that only applies to electrostatic charges; as best as I understand it the charges applied "cage" are distributed equally along the outer surface, which creates a uniform electric field, these fields somehow cancel each other. Though, I'm not sure about that because it seems to me that theory would be strongly dependant on the actual shape of the cage...
If a true Faraday cage does only applies to electrostatics, then what is taking place inside say, an automobile struck by lightning or shield providing protection from RF radiation? Those devices are subject to changing electrical fields, what keeps those fields from propigating inside the respective car/shield? I'm leaning towards what I understand about the skin effect, is that the right track? Would the car/shield be analogous to a solid conductor? If the shield in question is not made up of solid sheets of metal, but rather is an actual cage of conductors, would my best bet be examining the parallel current flow through the respective conductors?
I'm having a lot of difficulty finding straight answers on this, any help would be greatly appreciated. Feel free to throw in any pertinent equations.
Thanks.
-John