A synchronous generator that uses an AC exciter and a rotary rectifier to provide excitation energy for a coaxial generator field.
The brushless alternator is actually composed of two generators on the same shaft, one auxiliary generator as the exciter and one as the main generator. The winding of the exciter provides excitation to the auxiliary rotor on the armature, so that the rotor generates alternating current, which is rectified and then connected to the rotor of the main generator to generate a magnetic field, which in turn provides excitation to the stator of the main generator, and then the stator of the main generator generates alternating current output.
