What is a magnetic sensor? What are the categories?

Magnetic sensors are sensors used to measure the magnitude and direction of magnetic fields.

1. Hall sensor

A sensor that uses the Hall effect to measure the magnetic flux density and outputs a voltage proportional to the magnetic flux density. Easy to use, it is mainly used for non-contact switching applications such as opening and closing detection of objects such as doors and laptop computers.

2. MR sensor

Magneto Resistance sensor is also called magnetoresistive effect sensor, which uses the change of object resistance due to magnetic field to measure the size of geomagnetic field.

It is Higher?and consumes less power than Hall sensors, so it is a widely used magnetic sensor. In addition to it?being used for geomagnetic detection, such as an electronic compass, it can also be used for motor rotation and positioning.

3. MI sensor

MI (Magneto Impedance) sensor is a next-generation magnetic sensor, which uses a special amorphous wire and has a magnetoresistive effect.

Its sensitivity is more than 10,000 times higher than that of Hall sensors, and it can measure small changes in geomagnetism with high precision.

It is suitable for azimuth detection (electronic compass) with ultra-low power consumption, as well as high-sensitivity features such as indoor positioning and metal foreign object detection.

4. Geomagnetic sensor

There is a magnetic field around the earth called geomagnetism.

A geomagnetic field sensor is a sensor that detects the geomagnetic field, also it?called an electronic compass.

Geomagnetic field sensors detect the direction of the earth's magnetic field.

The geomagnetic field sensor adopts the form of two axes of X and Y, and adds three axes of Z to measure the magnetic force value in each direction.

If it is not considering?tilt, such?as a simple compass, only the values for the X and Y axes are used. When?it?is considering tilt, the 3-axis value of the geomagnetic sensor should be combined with the acceleration sensor to achieve the correct correction.

When the earth's magnetic induction element rotates horizontally, the center of the circle in the output distribution diagram will not be affected by the surrounding magnetic field.

However, in fact, the center will move due to the influence of the ambient magnetic field, so adjustment is required to move the center of the circle to zero.

The North Pole output by the Earth's magnetic field sensor is called Magnetic North (the North Pole is slightly off). Using the above formula to calculate the angle of magnetic north, the direction can be easily determined.