Brushless vs Brushed Electrical DC Motors

Electric motors convert electricity into mechanical energy. Most electric motors operate through an interaction between the motor’s magnetic field and winding alternating current (AC) or direct current (DC). Electric motors are used in a wide variety of applications, from fans and power tools to appliances and electric vehicles.

DC electric motors can be further classified into two common types: brushed and brushless. Each type delivers various performance benefits for different applications. Here, we will discuss how DC electric motors work and the differences between brushed vs brushless DC motors to help you determine the ideal electric motor for your application.

How Does a DC Electric Motor Work?

A DC electric motor takes electrical power from a direct current and converts that energy into mechanical rotation. Although they can vary in size and power, DC motors typically contain two primary components: a stator with a set of stationary magnets, and an armature with one or more windings of insulated wire which are wrapped around the motor’s core to concentrate the magnetic field. When the motor is powered by a direct current, a magnetic field is created within the stator, which interacts with the magnets to generate enough torque on the armature to cause it to rotate. 

Brushed vs Brushless DC Motors

DC motors can be brushed or brushless. Although they both function on the same principles of attraction and repulsion between coils and magnets, each type has benefits and drawbacks that may make one a better option than the other.

Brushed DC Motors

As the name implies, brushed DC motors have brushes, which are used to commutate the motor and cause it to spin. Brushed DC motors use an arrangment of wound wire coils, or the armature, which serves as a two-pole electromagnet. The commutator, or mechanical rotary switch, reverses the directionality of the current twice per cycle. This allows the current to flow through the armature, causing the electromagnet’s poles to pull and push on the permanent magnets outside the motor. Then, the commutator reverses the electromagnet’s polarity as its poles cross the poles of the permanent magnet. 

Advantages of brushed DC motors include:

• Low construction costs
• Suitable for extreme operating environments
• Can be rebuilt to extend their lifespan
• Inexpensive and simple controller
• Controller is not required for fixed speed

These benefits make brushed DC motors ideal for applications such as automotive vehicles, household appliances, and industrial equipment.

Brushless DC Motors

Brushless DC motors use a permanent magnet as their external rotor. Instead of a commutator, brushless DC motors have three phases of driving coils and a sensor to track the position of the rotor. As it tracks the rotor’s position, the sensor delivers reference signals to the controller, which in turn activates the coils one phase after the other. 

Advantages of brushless DC motors include:

• Less maintenance since they don’t have brushes
• Reduced size with better thermal characteristics
• Lower electric noise generation
• Higher speed range
• High efficiency

Common applications for brushless DC motors include power tools and electric vehicles as well as various uses within the manufacturing and computing industries.

Let TLC Help You Find an Electrical Motor for Your Application

Although similar, brushed and brushless DC electric motors offer different advantages and disadvantages for various applications. At Thomson Lamination Company, Inc., we are a leading manufacturer of high-quality motor laminations for electric motors. Our experts deliver precise motor lamination solutions with the capacity to meet high-volume production requirements. To learn more about our capabilities, or to get started on your electric motor lamination project, contact us today.