That is not correct, Ufo.

The magnetic field is a rotational movement in/of the aether. What happens when you drive a current trough a coil is that the current runs around in circles, creating a vortex in/of the aether, which is what we call a magnetic field. This is very, very much like spinning a flying wheel.

Now imagine taking a piece of rope and attack that to the side of a flying wheel. When you pull the rope round the flying wheel starts rotating. As long as you keep pulling and pulling round and round, you pull the rope and the flying wheel starts spinning faster and faster.

The moment you stop moving your hand, the flying wheel continues spinning and will pull at the rope. It will drag your hand along. IN THE SAME DIRECTION.

In other words: the direction of the force on the rope changes polarity. It changes from your hand pulling the flying wheel to the flying wheel pulling your hand.

With a coil, the same principle applies. The magnetic field does NOT change polarity and the current trough the coil winding also continues in the same direction. What does change is that the coil, instead of "sucking" current from your battery starts "pushing" the current to the load.

And that means that the *voltage* changes polarity, but the magnetic field does not.

Hi lamare!

The rotating magnetic field we refer to when talking about these motors is just the alternation of poles to -emulate- a smooth rotation in the scale of interaction we are working with.

Check out Wikipedia - Rotating Magnetic Field for a visual.

With time we will do it better, more like you mention.

Best wishes,
matt