There is at least one person in Thailand who knows what he's doing; his name on the board is 'chinsettawong'.
http://www.fieldlines.com/story/2004/11/17/75422/166
I advice to read this board and otherpower.com for a while. All the projects by the Dans are a good read, and will learn you a lot more than just the answers to the 2 questions you got.
I quote:
Magnetic Circuit--Picture a magnet to be almost like a battery. The lines of force from a magnet are said to originate at one pole and return to the other, just like a battery. Air is a poor conductor, both for electricy and for magnetic lines of force. In order to make best use of a magnet (and our copper wire) in an alternator, we need to have the strongest possible magnetic field. Just like copper is a good conductor of electricity, steel is a good conductor of magnetic fields. A good magnetic circuit involves steel between the poles with a gap (the airgap) where we need to utilize the field. In an alternator, our wires should occupy the airgap, it should be no wider than necessary, and every other part of the magnetic circuit should be of steel. We can either use steel laminates (laminated steel reduces eddy currents) or we can have magnets on each side of the coil(s) moving together with steel behind them. Again, look at our various wind turbine experiments to see. It should be said that some of them, like the wooden alternator and the all wooden windmill have very poor magnetic circuits.
Quote from this link:
http://otherpower.com/otherpower_wind_tips.html
Succes.
