What does an elementary AC generator have that a DC generator does not?

An elementary AC generator features split rings, which serve a specific function in the generation of alternating current. In an AC generator, these split rings provide a connection between the rotating coils and the external circuit in such a way that the current produced alternates direction as the coils rotate within the magnetic field. This is essential for the operation of an AC generator, as it facilitates the continuous switching of current direction that defines alternating current.

In contrast, a DC generator employs a commutator, which is designed to convert the alternating current generated in the coils into direct current. Similarly, while both types of generators may utilize brushes to conduct current, the mechanisms by which they operate differ significantly, particularly in regard to the type of current they generate. The rotating magnets are commonly found in both AC and DC generators, further distinguishing the role of split rings in an AC generator from the components of a DC generator.