Understanding Hall Effect Sensor

What is a Hall Effect Sensor?

A Hall effect sensor is defined as the magnetic component that is used for converting the magnetically encoded information into an electrical signal. This information could be speed, distance, position, etc. 

A Hall effect sensor is also known as a Hall sensor.

Working Principle of Hall Effect Sensor

A Hall effect sensor consists of a piece of a rectangular p-type semiconductor such as gallium arsenide, indium arsenide, or indium antimonide through which an electric current is passed. The device is then kept within the magnetic field in which the magnetic flux lines exert a force on the semiconductor material such that the electrons and the holes get to either side of the semiconductor. This movement of the electrons and the holes are a result of the magnetic force which is experienced by the semiconductor material.

Due to the movement of the electrons and the holes towards the side, a potential difference is created between the two sides of the semiconductor. The movement of the charge carriers is then affected by the presence of the external magnetic field. 

The effect which produces a measurable voltage in the presence of the magnetic field is known as the Hall effect. This effect is named after Edwin Hall who discovered it in the year 1870. Hall effect can be used for understanding the type of magnetic pole and the magnitude of the magnetic field. It is also important to note that the potential difference is generated across the device if and only if the magnetic flux lines are perpendicular to the flow of current.

Applications of Hall Effect Sensor

The following two are the well-known applications of the Hall effect sensor:

  • Positioning sensing
  • Direct current transformers

Positioning Sensing

The most well-known application of the Hall effect sensor in the industry is to detect the presence of magnetic objects. One common example of this application is the use of the Hall effect sensor in the brushless DC motors. Here, the sensors are used for detecting the position of the rotor.

Direct Current Transformer

In direct current transformers, the Hall effect sensors are used for measuring the current contactless. Here, the sensors are placed between the gap in the magnetic core such that the direct current magnetic flux is measured which is used for calculating the DC current in that conductor.

Advantages of Hall Effect Sensor

The following are the advantages of the Hall effect sensor when it is used as a switch:

  • It can be used as a switch such that the price of the Hall effect sensor switch would be lesser than the mechanical switch.
  • The Hall effect sensor switch can work at the higher frequencies where the mechanical switches fail.
  • A solid-state switch is used in a Hall effect sensor switch and therefore, there is no fear of contact bounce.
  • This switch can be used in any harsh environmental conditions as the switch is sealed in a package.

The following are the general advantages of the Hall effect sensor:

  • It can be used for measuring the magnetic fields.
  • It can also be used for measuring the sign as well as the amplitude.

Disadvantages of Hall Effect Sensor

When the Hall effect sensor is compared with the magnetometers or sensors that are based on magnetoresistance, the power of accuracy during the measurement is lower. 
Stay tuned to understand the application of Beer-Lambert law and its advantages and disadvantages.


Back to top button