Electric motors are used to convert electrical energy to mechanical energy. The AC and DC motors are two types of electric motors.
Key Takeaways
- AC motors run on alternating current, while DC motors use direct current.
- AC motors are more energy-efficient and require less maintenance, while DC motors offer greater speed control and a simpler design.
- AC motors dominate industrial applications, while DC motors are common in small appliances and electronic devices.
AC vs DC Motor
The difference between AC and DC motors is that they use different types of current. The AC motor uses an alternative current and turns it into energy by the electric motor.
AC motor is a powerful motor and is always preferred over DC motor because of their efficiency and easy availability. The power for the AC motor is supplied from the AC.
The DC motor is an electric machine or motor that uses direct current and converts electrical energy to mechanical energy. Various projects and experiments use DC motors as the source.
Comparison Table
| Parameters of Comparison | AC Motor | DC Motor |
|---|---|---|
| Power source | The AC motors use alternating current only and do not work with anything else. The alternative current goes through the electric motor’s input and is converted as mechanical energy. | The DC motors derive their current from direct current. Some of the power sources of direct current are the DC power supply and batteries. The AC to DC converter is occasionally used. |
| Usage | The AC motors are specifically utilized in circumstances where powerful performance is required. Also, it is used for longer periods. | The DC motors come in handy in circumstances that require more motor speed. The motor speed can be limited externally. |
| Life expectancy | The AC motors have a longer life span. As the AC motors do not possess commutators and brushes, they have a longer life expectancy period. | The DC motors have a short and limited life span. As the DC motors possess commutators and brushes, the life expectancy is limited. |
| Speed control | The AC motor’s speed can be controlled by changing the frequency. This is performed by using an adjustable frequency drive control. | The DC motor’s speed can be controlled by changing the armature winding’s current. By varying the armature winding’s current, DC motors can be kept in control. |
| Efficiency | The AC motors are less efficient than DC motors. As AC motors have induction current loss and possess a motor slip, the efficiency is reduced. | The DC motors are more efficient than AC motors. As DC motors do not have any induction current loss or a motor slip, the efficiency of DC motors is high. |
What is AC Motor?
AC motor means Alternating current motor. AC motors get supplied with power from the Alternative current.
To start the operation, the AC motor requires equipment like a capacitor. AC motor’s speed can be controlled by differing the current flow’s frequency with the help of variable frequency drive.
AC motors have two types. They are Synchronous motors and Asynchronous motors.
On the other hand, Asynchronous motor drives at a speed less than that of a synchronous motor. It is also known as an induction motor. Asynchronous motor is used frequently due to its reliability and usefulness.
What is DC Motor?
The DC motor is a rotary electric motor used for the conversion of energy. The DC motor is also known as the direct current motor.
The DC motors are the product of the early 19th century. When it was invented in the 1840s, dc motors were unsuccessful. The heavy battery usage required to run these dc motors was expensive and was of low quality. With the advent of rechargeable batteries, DC motors were used extensively.
An interaction occurs between an electric field and a magnetic field. A new mechanical force is produced out of the interaction between those two fields.
Fleming’s left-hand rule explains the direction of the motor’s rotation. According to the rule, the middle, index and thumb fingers are extended mutually perpendicular.
Main Differences Between AC and DC Motor
- The AC motors use alternating current, which is used to turn into mechanical current. The DC motors use direct current, which is converted into mechanical current.
- The AC motors have three different input terminals, as RYB are present within them. The DC motors have two different input terminals, as positive and negative are present within them.
- The AC motors are controllable by changing the frequency of the motor. The DC motors can be limited by changing the armature winding’s current.
- The AC motors are very slow in responding to the change in load. The DC motors are very quick in responding to the change in load.
- The AC motors are less efficient because of the induction current loss and motor slip. The DC motors are more efficient because there is no induction current loss and motor slip.
Last Updated : 30 July, 2023
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Piyush Yadav has spent the past 25 years working as a physicist in the local community. He is a physicist passionate about making science more accessible to our readers. He holds a BSc in Natural Sciences and Post Graduate Diploma in Environmental Science. You can read more about him on his bio page.
Understanding the basics and the historical evolution of DC motors was very interesting and adds credibility to this article.
I appreciated the historical context and the detailed explanation of DC motors. It adds depth to the understanding of these motors.
The article effectively summarizes the main differences between AC and DC motors, making it a valuable source of information.
Absolutely, I found the section on power source and usage to be particularly helpful.
I completely agree. The clear explanations and detailed comparisons are highly beneficial.
The detailed description of AC motors being more energy-efficient and having less maintenance compared to DC motors is very useful.
Absolutely, it’s important to understand the efficiency and life expectancy differences between AC and DC motors, especially for industrial applications.
This article effectively explains the advantages and disadvantages of both AC and DC motors, making it easier to understand the applications of each type.
I couldn’t agree more. The information on life expectancy and efficiency of the two motor types adds great value to this article.
The explanation of how AC motors use alternating current and the characteristics of AC motors is quite enlightening.
I completely agree. The section on the speed control of AC motors was particularly interesting.
The detailed explanation of the life expectancy and speed control of both AC and DC motors is very insightful.
Absolutely, the clarity provided in this article is commendable.
I found the comparison table to be particularly helpful in understanding the differences between AC and DC motors.
Thank you for the informative article! It’s great to understand the key differences between AC and DC motors.
Yes, I agree. Understanding the different applications and characteristics of each type of motor is essential.
Absolutely, the detailed comparison table provides a clear overview of the differences in power source, usage, life expectancy, speed control, and efficiency.
Great article. The explanation of how electric and magnetic fields interact to produce mechanical force in DC motors was fascinating.
The explanation of AC motors and the difference between synchronous motors and asynchronous motors is very informative.