Analyzing the working principle of Hall type speed sensors

Hall type speed sensor is a sensor made using the principle of Hall effect.

The Hall effect refers to the phenomenon where when a current passes through a semiconductor substrate (Hall element) in a magnetic field and the direction of the current is perpendicular to the direction of the magnetic field, the charge is displaced to one side by the force of the magnetic field,

A voltage proportional to the current and magnetic field is generated on the lateral side of the Hall element perpendicular to the current and magnetic field, and this voltage is called the Hall voltage.

The principle is shown in the following figure:

Hall type sensors also generate pulse voltages by changing the magnetic field strength of the Hall element when the signal disk passes through the sensor,

Due to the relatively low signal strength generated by Hall sensors, an amplification circuit is added inside the sensor.

Hall elements must have a reference voltage and working circuit in order to function properly,

The reference voltage on a car is usually 5V,

So Hall speed sensors in cars usually have three wires, which are:

5V power supply, circuit and signal lines.

Hall sensors are also one of the commonly used types of sensors in automobiles.