Charging System Principle of Operation

Charging System Principles of Operation

Charging Systems (Brush or Brushless) use the principle of electromagnetic induction to generate electrical power. Electromagnetic induction occurs in a generator when a magnetic field is rotated within a stationary conductor. The magnetic field can be generated by permanent magnets or as in the case of the automotive generator by powerful electromagnets.

Passing electric current through a wire or winding causes a magnet field to surround the wire or winding. The number of turns in the winding and the magnitude of the current flowing through the winding determine the magnetic field strength.

The strength of the field is further increased by surrounding the coil with pole pieces. The poles will take on the polarity (North or South) of the side of the coil they touch or the ones they are closest to. The combined windings (field coil) and pole pieces are referred to as the rotor. Output of the generator is regulated through control of field coil intensity.

An examination of single phase AC voltage generation, will aid in the understanding of 3 phase AC voltage generation.