The Hall effect, discovered by E.H. Hall in 1879, defines the relationship between the magnetic field and the induced voltage, which is completely different from the conventional induction effect. When an electric current passes through a conductor in a magnetic field, the magnetic field exerts a force on the electrons in the conductor perpendicular to the direction of their motion, creating a voltage difference between the two ends of the conductor.
Hall sensors are divided into switch type and linear two kinds, the difference between the two lies in the linearity of Hall plate on the one hand, and the different application on the other hand.
Switch type Hall sensors are mainly used for proximity switches or speed sensors, linear Hall is usually used for Hall current sensors or for measuring magnetic induction intensity. The following takes Hall current sensor as an example to briefly explain its working principle:
Hall current sensor is a sensor that converts a large current into a small voltage signal using Hall effect. The actual design of Hall sensors often amplifies the weak voltage signal to the standard voltage or current signal through the operational amplifier and other circuits.
The Hall current sensor made from the above principle is called \"open loop Hall current sensor\".
Later generations in order to improve the performance of the sensor, and slightly modified, is to use a compensation winding to generate a magnetic field, through closed-loop control, so that it is equal to the magnetic field generated by the measured current, in the opposite direction, to achieve the effect of cancelling each other, at this time, the current in the compensation winding is proportional to the size of the measured current, this sensor, It is called a closed-loop or magnetically balanced Hall current sensor.