DC electric motors have evolved significantly since their initial development in the early 19th century. While first created to power machinery, these versatile motors have since evolved into diverse usage throughout many global industries. Today, brushed DC motors are a popular choice due to their low cost and simplicity to drive.

At Pelonis Technologies, we offer innovative products at competitive pricing, including a selection of brushed DC motors suitable for even the most difficult industrial conditions. Here, we will discuss what a brushed motor is, how it works, and the benefits of using brushed DC motors throughout various applications.

What Are Brushed DC Motors?

Brushed DC motors are one of the most simple types of DC motors. Frequently driven by batteries, they are a low-cost and easy-to-drive electric option that works well in extreme operating environments. A brushed DC motor features permanent magnets inside its outer body, as well as an armature inside that rotates.

The armature coil sits between the permanent magnets and is powered by brushes to create a magnetic field. The electric current through the brush to the armature coil drives the rotor. The density and number of coils wound around the motor determine the motor's properties. Compared to brushless DC motors, a brushed motor is significantly more simple in design and cost-effective to produce.

What Are the Main Components of Brushed DC Motors?

Brushed DC motors are fairly simple. Unlike brushless DC motors, they do not require complex electronic components to achieve motion. Instead, they are made up of only four basic components: a stator, rotor, commutator, and brushes.

Stator

The stator is the stationary, outside component of a DC motor. It generates a magnetic field around the rotor using either electromagnetic windings or a permanent magnet. This magnetic field is what drives the armature's rotation.

Rotor

Also referred to as the armature, this part of the motor is made up of arms surrounded by one or more electric windings. When energized by an external current, these electric windings generate a magnetic field. The magnetic poles in the rotor are attracted to the opposing poles the stator field generates and repelled by their similar poles. This reaction is what causes the rotor to spin.

Commutator

Since DC motors don't use external current switching devices, they rely on a mechanical connector instead. This connector is called the commutator. Commutators make a connection between the rotors and the brushes. They are comprised of a segmented copper sleeve mounted onto the rotating shaft. Commutators receive electric current from the brushes.

Brushes

The motor's brushes are connected to the DC power source. When voltage is applied, and the motor turns, the brushes rotate and slide over the commutator. This creates a variable magnetic field.

How Do Brushed DC Motors Work?

All brushed DC motors operate in the same way. First, an electric current is applied to the rotor, causing it to spin 180 degrees. To travel beyond this, the poles of the motor's electromagnet must switch. As the rotor spins, its attached carbon brushes come into contact with the stator, switching the magnetic field and allowing the rotor to rotate 360 degrees.

Brushed DC motors typically operate at low speeds. They can be driven by a simple pulse width modulation (PWM) controller to vary the voltage supplied to the motor. This controls the speed in one direction and provides the torque needed for the motor to drive.

One of the biggest advantages of brushed DC motors is that they offer simple speed control without the need for complicated electronics. Instead, the speed is controlled using variable supply voltage. The voltage is applied proportionally to the rotational speed, while torque is proportional to the current. To achieve more precise and accurate operation, electronic speed controls have been developed. Changing the rotational direction can be achieved by reversing the armature connections or magnetic field.

What Are the Benefits of Brushed DC Motors?

Brushed DC motors come with several key advantages that make them the preferred choice over brushless DC motors in certain applications:

High-starting-torque
High starting torque. High-torque brushed electric motors are ideal for applications that need to get up to speed very quickly.
Low-cost
Low cost. Compared to brushless DC motors, brushed DC motors are relatively inexpensive to produce and purchase.
Well-suited-to-industrial-environments
Well-suited to industrial environments. Due to their high starting torque, these motors are well-suited to industrial environments.

What Are the Applications of Brushed DC Motors?

Brushed DC motors are used throughout many diverse applications, from home appliances to consumer electronics, and especially industrial applications. Their popularity is partially due to how easy it is to vary their speed-to-torque ratio. Additionally, due to the simplicity of their design, they are inexpensive to manufacture and purchase. For this reason, they are used in many applications where the host device will likely fail before the motor.

Despite the widespread shift from brushed to brushless motors, there are still many situations where a brushed motor is the best choice. In applications that require low cost, sufficient reliability, and adequate performance, brushed DC motors are a good option. Some of the most common applications of brushed DC motors include:

  • Inexpensive toys
  • Automatic car windows
  • Power tools
  • Paper machines
  • Car seat adjustment controls
  • Cranes
  • Steel rolling mills

Many industrial applications use brushed DC motors for both low and high-power purposes as well as fixed and variable-speed electric drives.

Learn More About Brushed DC Motors with Pelonis Technologies

Brushed DC motors serve as a reliable power solution for industry-diverse applications. Due to the simplicity of their design, they are cost-effective and dependable in addition to being an excellent choice for high starting torque applications. At Pelonis Technologies, we have over 25 years of experience developing innovative products at great prices. Whether you're in the automotive, HVAC, appliance, or medical industry, our team can help you find the right solution for your application. To learn more about the brushed DC motors we offer, contact us or request a quote today.