What Are Brushed DC Motors and How Do They Work

Motors are foundational components for a wide variety of applications, coming in the form of electrical machines that are capable of converting electrical energy into harnessable mechanical energy for work. Out of the many variations that exist, brushed DC motors are a longstanding choice that offers a simple yet efficient solution for conversion. In this blog, we will dive into the design of these motors and why they continue to be a reliable option for numerous applications.

At the core of a brushed DC motor lies its construction, which includes a stator, rotor or armature, brushes, and a commutator. The stator is the stationary part of the motor, which is made up of magnets or windings that produce a magnetic field during operation. The rotor, on the other hand, is the moving part of the assembly, consisting of windings connected to a commutator. Lastly, the brushes are made of carbon or graphite and are in constant contact with the commutator, ensuring the transfer of electrical current.

The working principle of a brushed DC motor is rooted in the interaction between the magnetic field of the stator and the current flowing through the rotor windings. When an electric current is applied to the motor, it flows through the brushes and commutator into the rotor windings. This current generates a magnetic field around the rotor, which interacts with the magnetic field of the stator. This interaction creates a force that causes the rotor to turn, and the commutator ensures that the direction of the current in the windings reverses at the appropriate time to uphold continuous rotation.

One of the primary advantages of brushed DC motors is their simplicity and ease of control. For example, they can be directly connected to a DC power source, and the speed of the motor can be adjusted by varying the voltage applied. This makes them an ideal choice for applications where precise speed control is essential, such as in conveyor belts, robotics, and small household appliances.

Brushed DC motors also offer a high starting torque, which makes them suitable for applications that require significant force at startup. This characteristic is particularly beneficial in automotive applications, such as in electric windows and windshield wipers, where immediate and powerful motion is necessary.

Despite their many advantages, brushed DC motors do have some limitations that are important to be aware of when making a potential purchasing decision, an example being the wear and tear of the brushes and commutator during operation. As the motor functions, the brushes continuously make and break contact with the rotating commutator, leading to gradual wear. This necessitates periodic maintenance and replacement of brushes to ensure optimal performance. Additionally, the friction between the brushes and commutator can generate electrical noise and reduce overall efficiency, which is also important to note.

To mitigate some of these issues, different types of brushed DC motors have been developed, each suited for specific applications. For instance, permanent magnet DC motors use permanent magnets instead of windings in the stator, resulting in a more compact and efficient design. Meanwhile, series wound and shunt wound DC motors offer variations in performance characteristics, such as torque and speed control, catering to diverse industrial needs.

Despite the advent of brushless DC motors, which address many of the maintenance concerns associated with brushed DC motors, the latter remain a popular choice in numerous industries. This is a result of their simple design, ease of control, and high starting torque that makes them a reliable option for many applications. For example, DC motors find implementation within many modern devices ranging from power tools and toys to automotive systems and industrial machinery.

For businesses and individuals seeking high-quality brushed DC motors, NSN Distributor, a platform belonging to ASAP Semiconductor, offers an extensive selection. Whether you require motors for industrial machinery, automotive applications, or consumer electronics, NSN Distributor provides a reliable source for all your needs with over 2 billion items ready for purchase with competitive pricing options guaranteed. Take the time to explore the website at your leisure, and if anything you come across piques your interest, be sure to take advantage of our online Request for Quote (RFQ) service to obtain tailored pricing information. Our dedicated account managers will always be happy to assist you however they can, so be sure to take the first step of procurement today.