What is Hall Effect Sensor
- Such a sensing device that used to find the strength of the field and shows this value in the form of voltage is known as the Hall effect sensor. The value of the voltage at the output of the sensor is directly proportional to the strength of the magnetic field.
- These sensors have the ability to sense the nearby object without a physical connection, they also used to find the position of different objects in any machines or circuitry.
- These sensors are manufactured by such material through which current can pass easily and its output terminals are designed at an angle of ninety degrees to the movement of the direction.
- When this module is put in the field it converts the field in the voltage and display at its output. But the voltage value is very less at the output almost some micro-volts, to obtain suitable voltage level special amplifiers circuits are connected with it.
- The main function of this sensor is to find the value of the magnetic field but it can also be used for the measurements of the temperature, pressure and current.
- Advantages Of Hall Effect Sensor, Hall Effect Sensor in Smartphones, What is Hall Effect Sensor, Working of Hall Effect Sensor, a disadvantage of hall effect, circuit of hall effect, Hall Effect Sensor.
Working of Hall Effect Sensor
- For an understanding of the working of Hall effect sensor first, we discuss the about Hall effect.
- According to Hall effect if the conductor is placed in a magnetic field at ninety degrees to the field and the current flowing through the conductor generates an electrical field.
- This sensor consists of the semiconductor substance like GaAs (gallium arsenide), InSb through which current passes.
- When we put this semiconductor material in the magnetic field the field lines exert the force on the electrons and the hole in the semiconductor.
- Due to the magnetic field lines force electrons and holes moves to produce a voltage at the terminals of the semiconductor material.
- The production of the voltage at terminals of the semiconductor substance is due to the Hall effect.
- To obtain the higher-level voltage at the terminals of the semiconductor device the direction of the field should be at ninety degrees.
Hall Effect Sensor in Smartphones
- This sensor is used in the mobile phone to lock and unlock the mobile screen.
- The Hall sensor follows this given below relation for its working in the mobile phones.
VH = IB/nte
- In this equation, VH is the Hall voltage.
- I is the current.
- B is the magnetic field.
- n is the density of the charges.
- t is the thickness of the mobile screen.
- e si the charge on the electrons.
- The flip cover consists of the magnet that generates a magnetic field due to which current starts to flow and this current produce voltage.
- These generated voltage used in the phone to operate the different circuits and lock and unblock the screen.
- This sensor in the phone saves the charging by automatically disable the screen.
- It is reliable, less expensive, can operate in diffrent temperature range.
- One thing you noticed that with the passage of time flip touch of phone not work properly. It is due to the magnetic that loss its magnetic strength with time and can generate enough voltage to produce a hall effect.
- As the voltage produced by the hall sensors are very less almost a few milli-volts, to amplify these voltages there should be special amplifier is connected with it that make phone expensive.
Advantages Of Hall Effect Sensor
- These are some advantages of the Hall effect sensor that are described here.
- This sensor can operate as an electric switch, it is less expensive than the manual switch and highly reliable.
- Its operate at a higher frequency than the manual switch.
- It can be installed in any environment condition because it is a sealed pack in the waterproof casing.
- These sensors can be used for the different ranges of the magnetic field measurements.
- With the detection of the field, it can also find the North and South poles of the magnet.
Applications of Hall Effect SensorPosition sensing
- It can work as a position sensor and tells about the location of different magnetic objects in industries.
- It also used in brushless direct current motors for the detection of the rotor and automatically switch the transistor direction.
- It also used in mobile phones for the automatic lock and unlock of the screen.
- It also used in the transformer for the detection of the direct current in the current transformer.
- For this purpose, it is mounted between the core and windings of the transformer flux variation in core and windings are measured by this flux current can be computed.
- These sensors are used in different fuel indicators. The main purpose of these sensors is to detect the movement of the floating component in the level indicator.
- There are 2 ways by which this sensing is done, the first one is by using vertical float magnet and the second one is rotating level sensor.
- In the first type that is vertical float system permanent is connected with the floating device.
- The conductive material through which current is passing is linked with the tank in the same line with the permanent bar magnet.
- With the increment in the fuel level, the increment in the field value will show in the output of the sensor as voltage.
- In 1960 Everett A. Vorthmann constructed such keyboard switch that follows the phenomena of the Hall effect.
- They did not get popularity due to their high cost in the market and remains for certain uses.