Comprehensive Analysis of Magnetic Field Sensor and Its Applications

The magnetic field sensor has basic characteristics such as non-contact measurement, high reliability, durability, and high measurement sensitivity. The magnetic field can penetrate many non-metallic materials and trigger exchange processes without direct contact with the target object. By using a magnetic conductor such as iron, the magnetic field can be conducted to a far distance and the signal can be transmitted from a higher temperature area. People convert changes in magnetic properties of sensitive elements caused by magnetic fields, currents, stress-strain, temperature, light, etc. into electrical signals, and devices that detect corresponding physical quantities in this way are called magnetic field sensors. According to the magnetic field sensor applications, they are used not only to detect the magnitude and direction of the magnetic field, but also in combination with permanent magnets and other components for non-contact detection of various non-magnetic quantities such as position, speed, angle, temperature, and current.

Application of magnetic sensors in industry

In the industrial application field, the most popular type of AC magnetic field sensor is the current sensor, which includes shunt resistors, Hall effect integrated circuits, current induction transformers, open-loop and closed-loop Hall devices, and magnetic flux gate sensors.

Application of magnetic sensors in motors

In brushless motors, magnetic field sensors are used for rotor magnetic pole position sensing and stator armature current commutation. Many magnetic field sensors, such as Hall devices, Magnetoresistive devices, and magnetoresistive devices, can be used, but the most commonly used is still Hall devices. In addition, magnetic field sensors can also be used for motor overload protection and torque detection; AC inverters are used for motor speed regulation, with excellent energy-saving effects. As the use of magnetic cylinder position sensor shows more and more advantages, it is gradually replacing optical encoders for speed detection and control of motors.

Application of magnetic sensors in energy management

The automatic monitoring system of the power grid needs to collect a large amount of data, and after being processed by a computer, it monitors the operation status of the power grid, adjusts the load distribution, and provides safety protection. Each control link of the automatic monitoring system can be realized using current sensors, transformers based on magnetic field sensors, etc. Hall current sensors have long been used in power grid systems. Energy meters made with Hall devices have also shifted from development to practical use. They can automatically calculate fees and display power factor for adjustments at any time, ensuring efficient use of electricity.

Application of magnetic sensors in traffic control

Traffic accidents and congestion are major problems in urban and interurban transportation. At present, many countries are strengthening the development and construction of driving support road systems, intelligent transportation systems, and road traffic information systems. In these new systems, high-sensitivity, high-speed response micro magnetic sensors have a significant role to play.

Application of magnetic sensors in the automotive industry

In automobiles, they are mainly used for parameter detection such as speed, inclination, angle, distance, proximity, position, as well as navigation and positioning. For example, speed measurement, pedal position, gearbox position, motor rotation, power steering torque measurement, crankshaft position, inclination measurement, electronic navigation, anti-lock braking system detection, parking positioning, defect detection in airbags and solar panels, seat position memory, and improvement of navigation system heading resolution. In energy saving and consumption reduction, especially when manufacturers are currently facing pressure to reduce carbon emissions or other pollutants, one key area is motors, which are transitioning from pulley systems with friction to electronic motors that can be controlled on demand. At the same time, electronic motors are transitioning to more efficient and reliable brushed DC motors, and the application of magnetic field sensors can make motor control or commutation more precise.