The Application of Magnetic Field Sensor in the Industrial and Medical Fields

The magnetic sensor market consists of Hall-effect and magnetic resistive semiconductor ICs used for tracking angular velocity and linear angle in machines and products, or for detecting and processing magnetic fields to establish position relationships. In industrial and medical applications, magnetic sensors are used in motors to improve their energy efficiency. Sensors are also used in a range of medical devices involving some form of motor control, such as pumps.

Magnetic field sensors have wide industrial applications

In industrial applications, renewable energy systems such as solar installations and wind turbines have been the main growth points for magnetic field sensors. On the other hand, estimates suggest that electrical power consumed by all kinds of motors accounts for 45% of the total, and saving energy can be achieved by improving motor efficiency. Government legislation focuses on reducing energy consumption, which is good news for sensors.

Examples of motors using magnetic sensors include low-voltage AC and DC motors, three-phase induction motors, stepper motors and servo motors, single-phase motors and compact motor drivers. In other industrial applications, magnetic sensors can be used for uninterrupted power supply in machines such as computer servers, welding systems, robotic technology, railroad transportation infrastructure, off-road vehicles and forklifts.

In industrial applications, the most popular types of magnetic field sensors are current sensors, including shunt resistors, Hall-effect integrated circuits, current induction transformers, open-loop and closed-loop Hall devices, and magnetic flux gate sensors.

In high-current applications such as large variable frequency motors, open-loop and closed-loop Hall sensors use Hall-effect ICs in a small package; dedicated integrated circuits can also be included in the package to improve integration. Hall ICs are also used in industrial washing machine frequency converter control applications. In addition to current sensors, independent Hall-effect ICs or magnetic resistance sensor switches also exist in the smaller market of magnetic sensors, used for motor rectification to reduce ripple and improve performance, or for position measurement.

Magnetic field sensors play a critical role in medical applications

Magnetic field sensors are used in medical applications, although the market size is smaller than in the industrial sector, but they can save lives or improve the quality of life. They are mainly used in medical devices that use reversing sensors for motor control, such as breathing machine applications; infusion, insulin and syringe pumps; or kidney dialysis machines.

Another example of sensor use in the medical field is in simple centrifuges used to prepare samples. Sensors are used to help control small motors to make them quieter and more reliable.

Switches are also a prominent application, used in safe operating drug cabinets, or for bed adjustment and hearing aids. Giant magnetoresistance sensor ICs compete with Hall and reed switches in the hearing aid sector.