Magneto-sensitive position sensors are made of semiconductor elements that are sensitive to magnetic fields, such as Hall effect or magnetoresistance effect elements. Common magnetic-sensitive position sensors include Hall elements or Hall integrated circuits, magnetoresistor and magnetoresistive diodes. Among them, Hall element and Hall integrated circuit based on the principle of Hall effect are collectively referred to as Hall effect magnetic sensor, or Hall sensor for short. When a current flows through a semiconductor in a magnetic field, a voltage (Hall electromotive force) is generated laterally. This phenomenon is later called the Hall effect. The Hall element uses the principle that the Hall electromotive force it generates is proportional to the orthogonal magnetic field strength. However, the Hall element is thin and fragile, its Hall electromotive force is small, and requires an external amplifier circuit, which is inconvenient to use.
The Hall integrated circuit is made on the basis of the principle of Hall effect, using integrated packaging and assembly technology. The Hall element and necessary peripheral circuits are integrated inside. It can easily convert the magnetic field signal into a larger amplitude electrical Signal; At the same time, it has the requirements for reliable operation withstand the industrial application environment. The Hall IC has the characteristics of non-contact, low power consumption, long service life and high response frequency. It is encapsulated by plastic materials into an integration, so it can work reliably in various harsh environments. Because the Hall position sensor has the advantages of simple structure, small size, flexible and convenient installation, easy electromechanical integration, and low price, it is widely used at present. At present, the Hall IC sensor is the main rotor position sensor used in brushless DC motors.
This article is taken from ------"Permanent Magnet Brushless DC Motor Technology"