Difference Between AC And DC Motor

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Acknowledging the difference between AC and DC motors is crucial not only from the perspective of board exams. But also, for the practical demonstrations as well as various projects. There are several points of differences between the DC motor and AC motor. One of the most common differences in AC and DC motors is the type of current flowing that is turned into energy by these motors. Moreover, AC motors are well-known for their enhanced efficiency and power output as compared to DC motors that are famous for their output range and speed control.

The detailed difference between the AC motor and DC motor in the tabular form is provided for a better understanding of students. 


What are AC Motors?

The coils wrapped around the output shaft generates a magnetic field producing energy in an AC motor. Talking about AC and DC motor differences, AC motors are durable, efficient, and even flexible that make them a worthwhile solution for several power generation needs. There are two foremost types of AC motors, i.e., Synchronous and Induction AC motors. AC motors have wide applications such as water heaters, food service pumps, garden equipment, and more.


How DC Motors Vary from AC Motors?

DC motors use the energy produced from batteries or other power sources generated that offer constant voltage. Made up of several parts, DC motors control, offer better speed variation and produce more torque compared to AC motors. One of the crucial differences between an AC generator and a DC motor is that the DC motor includes a commutator and brushes.

 

By knowing the major comparison between AC and DC motors, selecting the correct demonstration becomes easy for students. Following is the major difference between AC and DC motor: 


Difference Between AC & DC Motor

Points of Difference

AC Motor

DC Motor

Current Input

When an alternating current (AC) is passed as an input, then only the AC motor works.

Dc operates when Direct Current supply is provided. The motor might operate with AC power supply in the DC series motor. However, for shunt motors, DC supply is necessary.

Motor Starting

A single-phase AC motor needs a starting procedure. However, a three-phase AC motor requires no starting mechanism as it is self-starting.

It’s the main difference between AC and DC motors that later one is always self-starting. 

Input Terminals

Three input terminals are present in these motors.

Two input terminals that are; positive and negative exist in DC motors.

Types 

There are two types of AC motors, i.e., Synchronous AC motors plus Induction AC motors.

There are mainly two types of DC motors, namely; DC motors with brushes and without brushes.

Armature Characteristics

The armature is fixed in this type of motor, and the magnetic field rotates.

The magnetic field remains constant, and the armature rotates in DC motors.

Load Change

To the variable load, these motors don’t show a fast response. 

AC DC motor difference is that DC motors show a rapid response to the load change.

Commutators 

AC motors don’t contain commutators.

DC motors comprise commutators.

Brushes 

Like commutators, brushes are also absent in these motors. 

These motors involve carbon brushes. 

Life Expectancy 

Due to the absence of commutators and brushes, AC motors have a high life expectancy. 

The presence of commutators as well as brushes restricts the speed of these motors. Hence, it lessens the life expectancy of the DC motor. 

Speed Control

By changing the frequency, it’s easy to change the speed of an AC motor.

By varying the armature winding current, it’s easy to control the speed of DC motors.

Maintenance


Due to the nonappearance of commutators and brushes, AC motors require low maintenance. 

Due to the presence of commutators and brushes, DC motors require high maintenance.

Input Supply Phases

These motors can work on both single and three-phase supplies. 

DC motors work only when there is a one-phase supply. 

Applications 

Whenever there is a requirement for rapid speed or inconstant torque, these motors are preferable. 

When there is a requirement for changing speed or high torque, these motors are preferable.

Uses 

AC motors are commonly used in bulky industry productions.

DC motors are commonly used in minor domestic purposes. 

Efficiency 

The efficiency of AC motors is often less. It’s because of the motor slip and induction current loss. 

There is not any loss in the induction current or magnetic slip. Hence, DC motors have high efficiency. 

FAQs (Frequently Asked Questions)

1. What are the Advantages of AC Motor?

Ans: AC motor has its own advantages according to work suited. The work done through AC motors is usual for both commercial and industrial applications. The best reason why we operate using AC motors is easy operability and control. You perform every work with flexibility. AC motors take low startup power which could even protect components operating at other ends. It has a high durability with a long life span. You can easily control torque and speed at the variable stages. 

2. What are the Advantages of DC Motors?

Ans: Working with DC Motors is easily controllable and flexible. The first main advantage of DC motors is easy setup and installation. DC motors start with good power and torque; thus, the good flow of current. You get a fast response with stopping, acceleration, and start. With a DC motor, you work with a high standard voltage supply. DC motors are best for those machines that need a constant power supply, including elevators, vacuums, and sewing machines. It is also good for warehousing sorting equipment.

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