This lesson explains how a direct-current motor turns electrical energy into mechanical motion. It introduces the motor’s magnetic components, the production of torque, and basic ways to control speed.
A DC motor uses direct current (DC) to produce mechanical force. In common motor designs, current flowing through wire coils creates magnetic fields. A coil’s field strength and direction depend on the amount and direction of current, as well as the coil’s size and the material around which it is wound.
All flashcards
What is a DC motor?
An electrical motor that uses direct current to produce mechanical force, typically through the interaction of magnetic fields.
What are the stator and armature?
The stator is the stationary part that supplies a magnetic field. The armature is the rotating assembly, commonly containing wire windings around an iron core.
What is torque in a motor?
Torque is the turning force on the armature, produced by the interaction between magnetic fields.
What does commutation do?
Commutation changes the direction or connections of current in motor coils at appropriate points in the rotation so that useful torque continues.
What is regenerative braking?
It is a process in which a motor driven by the vehicle’s motion acts as a generator, converting some mechanical energy into electricity for storage or return to the power system.
Quiz questions
What maintenance issue can result from the physical contact in a brushed DC motor?Answer: Brushes and the commutator wear during operation.
How does a typical brushless DC motor switch current in its coils?Answer: An electronic controller switches the current in sequence.
Why should a series DC motor not be operated without a mechanical load?Answer: It can accelerate to a dangerously high speed.
How is the field winding connected in a shunt DC motor?Answer: In parallel with the armature.
In a cumulative compound DC motor, how does the series field relate to the shunt field?Answer: It aids the shunt field.
Based on the Wikipedia article DC motor, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.