In a separately-excited generator, what are the two circuits called?

In a separately-excited generator, the two primary circuits are indeed referred to as the field circuit and the armature circuit. The field circuit consists of the connection that supplies current to the field windings, which create the magnetic field necessary for the generator's operation. This magnetic field interacts with the armature circuit, where the actual electrical output is generated by converting mechanical energy into electrical energy via electromagnetic induction.

The field circuit is critical because its strength, controlled by the amount of current supplied, directly influences the output voltage of the generator. The armature circuit is equally important, as it contains the windings through which the generated current flows to provide power to the load. Understanding the distinction between these two circuits is fundamental for analyzing the performance and behavior of a separately-excited generator, especially in terms of voltage regulation and stability.