2.1.11 AC generators

AC Generator

What Is An AC Generator? An alternating current generator, or AC generator, produces an alternating current, which means the voltage produced alternately reverses from positive to negative polarity, producing a corresponding change in the direction of current flow.

How does it work? Much like a DC generator, an AC generator requires a coil to cut across the force lines of a magnetic field. This coil is attached to two slip rings, which deliver the current to and from the load destination, thus completing the circuit. Alternating current generators are often called alternators. During the first half turn, the coil cuts across the field near the magnet's north pole. Electrons travel up the wire, and the lower slip ring becomes positively charged. When the coil cuts near the South Pole of the wire during the second half turn, the lower slip ring becomes negatively charged, and electrons move down the wire. The faster the coil turns, the faster the electrons move, increasing the frequency (in Hertz) of the current produced by the generator.

Example: