What Is a Brushed DC Motor?
A brushed DC motor is a type of DC motor equipped with brushes that facilitate current flow through the rotor.
These motors are known for their simple control mechanisms, allowing easy manipulation of rotation direction and speed. They offer high starting torque and operate effectively across a wide range of speeds. Brushed DC motors are also favored for their straightforward mechanics, making them ideal for educational purposes and beginners. Additionally, they are cost-effective to produce and purchase.
However, the brushes in these motors are prone to wear due to contact with the rotor, necessitating periodic replacement and limiting the motor’s lifespan.
Applications of Brushed DC Motors
Brushed DC motors are used in diverse applications, including:
1. Power Tools
These motors are a popular choice for power tools due to their high starting torque and compact design, making them suitable for drills and vibratory tools used in construction and repair work.
2. Toys
Used in radio-controlled cars, helicopters, model airplanes, and more, brushed DC motors are preferred for their affordability and ease of control, enhancing the enjoyment of various toys.
3. Handy Fans
Handheld fans, especially useful in hot conditions, often rely on brushed DC motors for efficient air movement at low power.
4. Home Appliances
Common in electric toothbrushes, hand mixers, and hair dryers, these motors serve as a reliable power source in many small household appliances.
Principle of Brushed DC Motors
Brushed DC motors operate by the interaction between an electric current and a magnetic field. Key components include the rotor, stator, and brushes.
The stator, typically a permanent magnet or electromagnet, surrounds the motor’s rotation axis. The rotor, attached to the motor shaft, contains coils. Brushes supply power to the rotor while maintaining contact.
Upon powering the motor, current flows through the rotor coils, turning them into electromagnets. This creates a magnetic field that interacts with the stator’s magnet, generating torque and causing the rotor to spin. The brushes ensure continuous current supply and direction variation, maintaining the rotor’s rotation.
How to Select a Brushed DC Motor
Key considerations when selecting a brushed DC motor include:
1. Voltage Rating
Ensure the motor’s voltage rating matches the intended power supply. Using the correct voltage is crucial, as overvoltage can damage the motor.
2. Power
Select a motor with sufficient power capacity to handle your required torque and load. Higher power capacity usually translates to more robust performance under larger loads.
3. Mounting Method
Choose a mounting method, such as shaft-mounted or flange-mounted, that suits your application. Consider the available space and connection requirements.