Difference Between AC and DC Motor

Electric motors are the machines that convert the electrical energy from either the stored power or the direct electrical connection into mechanical energy. This is possible through the production of rotational force. Electric motors are of two types- one is an AC motor (powered by alternating current) and the other is a DC motor (powered by direct current). The clear concept about the difference between AC and DC motor very important. By knowing the AC and DC motor difference, it will be easy to select a suitable motor. In this article, we will deal with the detailed difference between AC and DC motor in the tabular form for easy understanding.

What is AC Motor?

This motor converts the alternating current into mechanical power by using the phenomena of electromagnetic induction. This motor is run by alternating current. Its two main parts are the stator and rotor. The stator is the stationary part of the motor, whereas the rotor is the rotating part of the motor. AC motors are of two categories one is single-phase and the other is three-phase.

The three-phase AC motors are useful in the industry for bulk power conversion from electrical to mechanical. For small power conversion, the single-phase AC motors are suitable. The single-phase AC motor is small in size, and it provides different kinds of services in the home, office, factories, etc. For most of the domestic appliances such as refrigerators, fans, washing machine, hairdryers, mixers, etc., use single-phase AC motor. The AC motor is also classified into the synchronous motor and the induction motor.

What is the DC motor?

A direct current i.e. DC motor is a type of electric machine which converts the electrical energy into mechanical energy. DC motors are consuming the electrical power through the direct current, and it converts this energy into the mechanical rotation.

These motors use the magnetic which is occurring from the electrical currents generated. It is further getting powers for the movement of a rotor fixed within the output shaft. This term ‘DC motor’ is used to refer to any rotary electrical machine that converts direct current electrical energy into mechanical energy.

DC motors are varying in size and power from the small motors in toys and appliances to large mechanisms that power vehicles. DC motors have two key components as stator and armature. The stator is the stationary part of the motor, whereas the armature rotates. In motor, the stator provides a rotating magnetic field that drives the armature to rotate.

Difference Between AC and DC Motor

The important difference between AC and DC Motor

Parameter	AC Motor	DC Motor
Definition	AC motor is the electric motor that is driven by an alternating current.	DC motor is the rotatory electric motor which converts the DC energy into mechanical energy.
Types	It is of two types which are synchronous AC motors and induction motors.	DC motor is of two types which are namely DC motors with brushes and DC motors without brushes.
Current Input	It uses AC current.	It uses DC current.
Input Phases	AC motors can run on both single-phase and three-phase supplies.	DC motors can run only on single-phase supply.
Motor Initiation	A three-phase AC motor is self-starting and single-phase AC motor requires a starting mechanism.	DC motors are always self-starting in nature.
Armature Position	In AC motors, the armature is stationary while the magnetic field rotates.	In DC motors, the armature rotates but the magnetic field remains stationary.
Input Terminals	This motor has three input terminals.	This motor has two input terminals.
Load Change	AC motors are less responsive to the change in load.	DC motors are fast responsive to the change in load.
Applications	AC motors are applicable to the need for high speed and variable torque.	DC motors are applicable to the need for variable speed and high torque.
Uses	Mainly used in large industries.	Mainly used in small domestic appliances.

After learning the difference between AC and DC Motor, let us learn their applications also.

Applications of AC motors:

• Home Appliances
• Compressor drives and systems
• Computers
• Conveyor systems
• Fans and air conditioners
• Hydraulic and irrigation pumps
• Transportation equipment

Applications of DC motors:

• Fabrication and production of industrial units
• Machinery having high and constant power need
• Warehouse sorting devices

FAQs about AC and DC motor:

Q.1:  What are the different types of losses in DC motor?

Solution: There are three kinds of losses in the DC motor, which are:

• Mechanical loss due to the friction between brush and bearings and other rotating parts.
• Iron loss due to eddy current and hysteresis.
• Copper loss occurring in the armature and in the field windings.

Q.2: Which motor is more efficient?

Solution: AC motor is less efficient whereas DC motor is more efficient.

Q.3: Which motor needs more maintenance?

Solution: DC motor needs more maintenance.

References:

https://en.wikipedia.org/wiki/AC_motor

https://en.wikipedia.org/wiki/DC_motor