Sensors in Brushless DC Motors: The Key to Performance and Monitoring*
The brushless DC (BLDC) motors are ubiquitous in our industrial and commercial daily life, from drones to robots to electric vehicles. Their efficiency, reliability, and precision make them essential components of many modern applications. But behind their smooth operation lie intelligent sensors that monitor and optimise each rotation. This article explores the main sensors integrated into BLDC motors and the importance of the data they provide.
1. The Encoder: Measuring Position for Precise Control
The encoder is a key sensor that measures the angular position of the motor shaft. There are two main types:
Incremental encoders: They generate pulses with each rotation, allowing the calculation of the rotor's speed and direction. Ideal for precise speed control.
Absolute encoders: They provide a unique position for each angle, even after a power cut, which is essential for applications requiring exact positioning.
This information allows real-time monitoring of speed and torque, ensuring optimal motor control.
2. Hall Effect Sensors: Tracking Position and Speed
Hall effect sensors detect the magnetic field generated by the rotor. Their main role: switching the motor phases at the right time.
By monitoring the frequency of signals sent by these sensors, it is also possible to measure the motor's speed accurately. Result: efficient energy management and reduced losses, while ensuring smooth and controlled rotation.
3. Temperature Sensors: Protecting the Motor and Extending Its Lifespan
Temperature is a critical factor for the reliability of BLDC motors. Temperature sensors, often based on thermistors or semiconductors, monitor the windings and internal components.
Excessive temperature can damage the motor. Thanks to these sensors, the controller can adjust the motor's operation — reduce the load or activate cooling — to prevent overheating and extend lifespan.
4. Telemetry and Remote Monitoring: Data Serving Maintenance
The integration of these sensors also enables telemetry. Data on torque, speed, and temperature can be transmitted to remote monitoring systems.
This functionality is particularly valuable in industrial environments where an unexpected shutdown can be costly. By analysing this data, it is possible to anticipate problems and plan preventive maintenance, reducing the risk of failure and optimising performance.
Conclusion
The sensors integrated into BLDC motors are much more than mere measuring devices. They constitute the intelligence of the motor, enabling real-time monitoring, performance optimisation, and failure prevention. Encoders, Hall effect sensors, and temperature sensors provide essential data which, when exploited via telemetry, ensure reliable and durable operation.
In a world where industry and mobility are becoming increasingly connected, mastering these sensors is essential to make the most of brushless DC motors.
*: The technical information presented in this article is provided for informational purposes only. It does not replace the official manuals of the manufacturers. Before any installation, handling or use, please consult the product documentation and adhere to safety instructions. The Torque.works site cannot be held responsible for inappropriate use or incorrect interpretation of the information provided.