A direct current (DC) machine is comprised of several interconnected components, each playing a crucial role in its operation, whether as a motor converting electrical energy into mechanical energy or as a generator performing the reverse. These components can be broadly classified into two categories: stationary elements, like the stator and its associated field windings, and rotating elements, such as the rotor (armature) with its windings, commutator, and brushes. For example, the field windings establish the magnetic flux necessary for energy conversion, while the armature windings carry the current that interacts with this flux to produce torque or generate voltage.
Understanding the function and interaction of these individual elements is fundamental to comprehending the overall performance characteristics of a DC machine, including its efficiency, speed regulation, and torque characteristics. Historically, DC machines were among the first practical electrical devices developed, powering everything from early industrial machinery to electric trams, and their robust design continues to find applications today in various industries, from automotive starters to robotics.