Conduction mechanism. When the current passes through a conductor perpendicular to the external magnetic field, the potential difference will be generated at both ends of the conductor perpendicular to the magnetic field and the current direction, which is the Hall effect. Hall-type speed sensor belongs to Hall-type sensor and is made by using the principle of Hall effect. Using the Hall effect, the displacement drives the Hall element to move in the magnetic field to generate Hall heating, that is, the sensor converts the displacement signal into an electrothermal change signal.
Hall effect speed sensor is a small closed speed sensor. It is connected with the shaft to be measured through a coupling. When the rotating shaft rotates, the rotation angle is converted into an electrical pulse signal for use by the secondary instrument. The sensor has the characteristics of small volume, simple structure, no contact, small starting torque, long service life, high reliability, good frequency characteristics and continuous measurement.
Hall speed sensor is a small closed sensor, which has the advantages of stable performance, low power consumption, strong anti-interference ability and wide temperature range. The principle is that when the magnetic field lines pass through the sensing elements on the sensor, the Hall potential is amplified and shaped by the Hall chip, and the generated electrical signal is used by the secondary instrument. When in use, as long as the small magnetic steel is attached to the rotating object, the sensor is fixed within a certain distance from the magnetic steel, and the S pole of the magnetic steel can be aligned for measurement.
Measurement error and compensation of Hall element
In the use of Hall element, there are many factors that affect the measurement accuracy. There are two main reasons: semiconductor manufacturing process and inherent characteristics of semiconductors. It shows the measurement error caused by zero error and temperature.
Hall speed sensor has several different structures. The input shaft of the magnetic turntable is connected with the rotating shaft to be measured. When the rotating shaft to be measured rotates, the magnetic turntable rotates with it. The Hall sensor fixed near the magnetic turntable will generate corresponding pulses when each small magnet passes by, and the measured rotating speed can be known by detecting the number of pulses per unit time. The number of small magnets on the magnetic turntable determines the resolution of the sensor's measuring speed.