The operating principle of an automotive starter motor is essentially an energy conversion process-based on Ampère's Law-that we first encountered in junior high school physics: specifically, the phenomenon wherein a current-carrying conductor experiences a force when placed within a magnetic field. The motor comprises essential components such as an armature, commutator, magnetic poles, brushes, bearings, and a housing.
Before an engine can operate under its own power, it must be set into rotation by an external force. The process by which an engine transitions from a stationary state to self-sustaining operation-facilitated by this external force-is known as engine starting. The three most common methods for starting an engine are manual starting, auxiliary gasoline engine starting, and electric starting. Manual starting, which employs either a pull-rope or a hand crank, is simple but inconvenient; furthermore, due to its high physical exertion requirements, it is suitable only for low-power engines and is retained in some vehicles merely as a backup method. Auxiliary gasoline engine starting is primarily utilized for high-power diesel engines. Electric starting, on the other hand, offers ease of operation, rapid starting capability, the capacity for repeated starting attempts, and the potential for remote control; consequently, it has been widely adopted in modern automobiles.
