Hall sensor technology has a wide range of applications in the automotive industry, including power, body control, traction control and anti lock braking system. In order to meet the needs of different systems, Hall sensor has three forms: switch type, analog type and digital type.
Hall sensor can be made of metal and semiconductor. The change of effect quality depends on the material of conductor, which will directly affect the positive ions and electrons flowing through the sensor. In the manufacturing of Hall components, the automotive industry usually uses three kinds of semiconductor materials, namely gallium arsenide, indium antimonide and indium arsenide. *The commonly used semiconductor material is indium arsenide.
The form of Hall sensor determines the different amplification circuit, and its output should adapt to the controlled device. This output may be analog, such as the acceleration position sensor or throttle position sensor, or digital. Such as crankshaft or camshaft position sensor.
When the hall element is used as an analog sensor, the sensor can be used as a thermometer in the air conditioning system or as a throttle position sensor in the power control system. Hall element is connected with differential amplifier and amplifier is connected with NPN transistor. The magnet is fixed on the rotating shaft. When the shaft is rotating, the magnetic field on the hall element is strengthened. The Hall voltage is proportional to the intensity of the magnetic field.
When Hall element is used for digital signal, such as crankshaft position sensor, camshaft position sensor or vehicle speed sensor, the circuit must be changed first. Hall element is connected with differential amplifier, and differential amplifier is connected with Schmitt trigger. In this configuration. The sensor outputs an on or off signal. In most automotive circuits, Hall sensors are current absorbers or ground signal circuits. To do this, you need an NPN transistor connected to the output of the Schmitt trigger. The magnetic field passes through the hall element, and the blade on a trigger wheel passes between the magnetic field and the hall element.https://www.ctsensorducer.com/