We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Electrical

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What is a DC Motor?

Jeff Petersen
By
Updated: May 17, 2024
Views: 114,656
Share

A direct current (DC) motor is a fairly simple electric motor that uses electricity and a magnetic field to produce torque, which causes it to turn. At its most simple, it requires two magnets of opposite polarity and an electric coil, which acts as an electromagnet. The repellent and attractive electromagnetic forces of the magnets provide the torque that causes the motor to turn.

Anyone who has ever played with magnets knows that they are polarized, with a positive and a negative side. The attraction between opposite poles and the repulsion of similar poles can easily be felt, even with relatively weak magnets. A DC motor uses these properties to convert electricity into motion. As the magnets within the motor attract and repel one another, the motor turns.

A DC motor requires at least one electromagnet, which switches the current flow as the motor turns, changing its polarity to keep it running. The other magnet or magnets can either be permanent magnets or other electromagnets. Often, the electromagnet is located in the center of the motor and turns within the permanent magnets, but this arrangement is not required.

To imagine a simple DC motor, a person can think of a wheel divided into two halves between two magnets. The wheel in this example is the electromagnet. The two outer magnets are permanent, one positive and one negative. For this example, the left magnet is negatively charged and the right magnet is positively charged.

Electrical current is supplied to the coils of wire on the wheel within the motor, and it causes a magnetic force. To make the motor turn, the wheel must have be negatively charged on the side with the negative permanent magnet and positively charged on the side with the permanent positive magnet. Because like charges repel and opposite charges attract, the wheel will turn so that its negative side rolls around to the right, where the positive permanent magnet is, and the wheel's positive side will roll to the left, where the negative permanent magnet is. The magnetic force causes the wheel to turn, and this motion can be used to do work.

When the sides of the wheel reach the place of strongest attraction, the electric current is switched, making the wheel change polarity. The side that was positive becomes negative, and the side that was negative becomes positive. The magnetic forces are out of alignment again, and the wheel keeps rotating. As the motor spins, it continually changes the flow of electricity to the inner wheel, so the magnetic forces continue to cause the wheel to rotate.

DC motors are used for a variety of purposes, including electric razors, electric car windows, and remote control cars. Their simple design and reliability makes them a good choice for many different uses, as well as a fascinating way to study the effects of magnetic fields.

Share
About Mechanics is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Jeff Petersen
By Jeff Petersen
Jeff Petersen is a freelance writer, short story author, and novelist based in Berkeley, California. He earned his B.A. in English and Creative Writing from Creighton University and loves putting his skills to work creating captivating content for About Mechanics. Jeff's articles cover a broad range of subjects, keeping readers informed and entertained with his insightful writing style.
Discussion Comments
By anon171631 — On May 01, 2011

what is the main difference between ac and dc motors?

By anon142333 — On Jan 12, 2011

This website has helped me gather information for my science fair project about building a DC motor.

By anon99051 — On Jul 25, 2010

what does it mean when it says: "To imagine a simple DC motor, think of a wheel divided into two halves between two magnets."

Can someone explain please?

By anon61871 — On Jan 23, 2010

this website helped for my science fair.

By anon37960 — On Jul 22, 2009

Brilliant :d

Jeff Petersen
Jeff Petersen
Jeff Petersen is a freelance writer, short story author, and novelist based in Berkeley, California. He earned his B.A....
Learn more
Share
https://www.aboutmechanics.com/what-is-a-dc-motor.htm
Copy this link
About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.

About Mechanics, in your inbox

Our latest articles, guides, and more, delivered daily.