Re: Transformer location/Safety

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Conner <steve@xxxxxxxxxxxx>


> Aluminum does not stop a magnetic field.  In high power Tokamaks 
> they wind the high current windings on the "outside" of the aluminum 
> container so the magnetic fields can effect the conductive plasma 
> inside the container.

Actually, I happen to know that they have to split the containment of 
a Tokamak into several sections with high resistance nickel bellows 
between them, to stop eddy currents in the containment walls and so 
let the magnetic field inside. It's just another of the little 
hassles that make a thermonuclear power plant in your garage a near 
impossibility ;-) I have the source here and can quote it.

Aluminium does kind of stop a magnetic field- all conductors try to 
expel magnetic fields from themselves- but it shields better at 
higher frequencies. Hence the comment by another poster about using 
it as RF shielding is valid. It can be difficult to shield 50 or 60Hz 
fields effectively, though. I've heard that sensitive audio 
transformers get enclosed in several nested shields of copper and 
mu-metal, like a Russian doll.

Steve