The magnetic field for 3 windings U, V, W is shown. The current i1 flows 'into' the picture at U2, and 'comes out' at U1. If all 3 windings U, V, W are arranged at 120 degree angles to each other, and 3 sinusoidal currents with 120 degree phase shifts to one another flow in these windings, then a rotating magnetic field results. This is the basic principle of electric machines.

• Move the time slider to see the magnetic field rotate.
• Press 'RUN' for continuous rotation of the field.
• Drag the red point of the current curve to change the current amplitude. The magnetic field will change accordingly.
• Drag the symbols of the windings (red 'o' and 'x') to change the location. Asymetric location will distort the magnetic field.
• Try to build a linear motor by rearranging the windings!