DC motors, with or without brushes, are used in a wide variety of applications, featuring a high level of starting torque and an ability to rotate at high speed. Brushless DC motors are quieter than brushed motors, with a longer life and lower maintenance requirements.
This page looks at where brushless DC motors are used and describes their applications in various fields.
Features and advantages of brushless DC motors
Let’s start with a simple explanation of what DC motors are. DC motors are electric motors that are powered by direct current. Features include rotation at high speed and the ability to deliver high starting torque. The motor’s speed and torque are controlled by means of the drive voltage.
DC motors can be broadly divided into brushed DC motors and brushless DC motors, depending on whether they use brushes as an electrode. The shorter life of brushed DC motors is because they are equipped with brushes and a commutator, which are both consumable parts. Brushless DC motors on the other hand, as their name suggests, do not have brushes. Instead, they are driven by turning the transistor in the drive circuit on and off based on the signal from a magnetic sensor inside the motor.
Because brushless DC motors don’t use consumable brushes and have their current flow switched electronically, they feature low maintenance and long life. Another attraction is that they run more quietly than brushed motors.
This low level of motor noise means they are frequently used to make household electronic devices and other such equipment operate more quietly.
Applications in home appliances and commercial electrical products
While daily life provides few opportunities to see brushless DC motors in action, they are frequently found inside commonly used home appliances. Air conditioners and refrigerators are two examples. Such appliances use fans to deliver chilled or warm air, and brushless DC motors are used to drive these fans.
Likewise, the motors are increasingly being used in electric fans. The blades of household fans rotate at very high speed and tend to make motor noise. Therefore brushless DC motors are widely adopted in models that feature quiet operation and fine-grained adjustment of fan power.
Another application for the motors is in commercial electrical products. Examples include feeding paper in laser printers, controlling the propellers and gimbal in drones, and turning of screwdrivers or saws in power tools. In other words, brushless DC motors are extremely versatile.