magnetic motors

[goskers]

Gentlemen,

I have been working on a magnetic circuit design for a ribbon tweeter which uses aluminum as the element. There has been an intersting question that popped up when I was discussing this problem with a few co-workers; how does a magnetic circuit move an aluminum element?

I did not think of this until my co-workers mentioned it. Every true ribbon that I know has a pure aluminum strung across the magnetic gap. Aluminum, being non-magnetic, should be impossible to move with a magnetic motor.

????

Thanks.

[Spiny]

The power is provided by current flow. This is the same way a normal speaker works - the coil is usually non-magnetic copper

a expert will be able to detail the force for a certain current through a magnet field - not my field

[ingvar ahlberg]

Neither is the copperwire in a voicecoil. It´s the ac signal fed through the ribbon or coil that forces it to throw itself back and forth in the static magnetfield

[Calvin]

Hi,

current flowing through a conductor -regardless of the material- creates a magnetic field. This field reacts upon the magnet´s magnetic field. Since the current through the aluminium strip will change its strength and direction, so does its magnetic field. A force develops between both fields and since the magnets are fixed, the conducting strip moves.

Electrostats basically do the same, but here you use an electrical field instead.
Thats all.

jauu
Calvin

[goskers]

Thanks for the help guys. I'm not sure as to why all of this info completely slipped my head.

[tryonziess]

Look up Lorentz force. It explains everything about this subject. Tad