How to Tell if a Motor is Brushed or Brushless?

Determining whether a motor is brushed or brushless can be done through various methods, including physical inspection, examining the electrical connections, and considering the operational characteristics. Here are some detailed steps to help you identify if a motor is brushed or brushless:

1. Physical Inspection

Brushed Motor

- Brushes and Commutator: Brushed motors contain brushes and a commutator. You can often see the brushes through ventilation slots or other openings in the motor housing. The commutator is a cylindrical component that the brushes contact.

- Housing: The motor housing may have slots or removable covers for brush maintenance.

- Sparking: When operating, brushed motors may produce visible sparking at the point where the brushes contact the commutator.

Brushless Motor

- No Brushes or Commutator: Brushless motors do not have brushes or a commutator. Instead, they rely on electronic controllers to manage the motor’s phases.

- Smooth Housing: The housing of a brushless motor is usually sealed and lacks access points for brush maintenance.

- Internal Electronics: Brushless motors often contain internal or external electronic speed controllers (ESCs) for operation.

2. Electrical Connections

Brushed Motor

- Two Wires: Brushed motors typically have two wires for power connection, one for positive and one for negative.

Brushless Motor

- Three Wires: Brushless motors usually have three wires, corresponding to the three phases of the motor. These wires connect to an electronic speed controller (ESC).

3. Operational Characteristics

Brushed Motor

- Control Simplicity: Brushed motors are controlled simply by varying the voltage applied to the two terminals.

- Maintenance Requirements: Due to brush wear, brushed motors require periodic maintenance to replace brushes and clean the commutator.

Brushless Motor

- Complex Control: Brushless motors require an electronic speed controller (ESC) to manage the switching of current to the motor windings.

- Higher Efficiency and Longevity: Brushless motors generally offer higher efficiency, more torque per weight, and longer lifespan due to the absence of brush wear.

4. Performance and Application

Brushed Motor

- Common Applications: Brushed motors are commonly used in simple applications like household appliances, toys, and basic tools.

- Noise and Vibration: Brushed motors may produce more noise and vibration due to brush and commutator friction.

Brushless Motor

- Common Applications: Brushless motors are used in applications requiring high efficiency and precision, such as drones, electric vehicles, and advanced robotics.

- Smooth Operation: Brushless motors typically operate more quietly and smoothly compared to brushed motors.

5. Manufacturer Specifications

- Datasheet or Label: Check the motor’s datasheet or label for information. Manufacturers usually specify whether the motor is brushed or brushless.

Conclusion

By inspecting the physical characteristics, electrical connections, operational behavior, and referring to manufacturer specifications, you can accurately determine whether a motor is brushed or brushless. Brushless motors generally offer superior performance and durability, making them suitable for more demanding applications, while brushed motors are often used in simpler, cost-sensitive applications.