An electric motor is a device that converts electrical energy into mechanical energy by utilizing the interaction between magnetic fields. The working principle of an electric motor involves the application of the Lorentz force, which is the force experienced by a current-carrying conductor in a magnetic field.
- DC motors – Run on direct current. Commonly used types include brushed DC motors and brushless DC motors. They provide precise torque control and speed variation.
- AC synchronous motors – Run on alternating current. The rotational speed is exactly synchronous to the frequency of the AC power supply. Common types are induction motors and synchronous reluctance motors.
- AC induction motors – The most widely used motor type. Consist of a stationary stator with coils and a rotating rotor. As the rotor turns it induces currents that create its own magnetic field.
- Single-phase induction motors – Common for smaller appliances. Can only produce rotary motion and require a split-phase start or capacitor start mechanism.
- Three-phase induction motors – Used for industrial applications. Can self-start and provide higher torque than single-phase motors.
- Permanent magnet motors – Contain permanent magnets in the rotor. Synchronous and brushless DC are common types. Generally more efficient than induction motors.
- Stepper motors – Rotate in discrete angular movements or steps. Used for precision motion control in applications like 3D printers.
- Servo motors – Provide position/speed control for use in robotics, CNC machines, and other servo applications. Often use brushless DC or stepping motor technology.
- Specialty motors – Such as microwave ovens (two-phase induction), disk drives (ultra-small brushless DC), and servos for aircraft controls.