- The Hall effect element is a type of transducer used for measuring the magnetic field by converting it into an emf.
- The direct measurement of the magnetic field is not possible. Thus, the Hall Effect Transducer is used for indirect measurement of magnetic field.
- The transducer converts the magnetic field into an electric quantity which is easily measured by the analog and digital meters is called hall effect transducer.
- The working principle of Hall Effect Transducer is based on Hall Effect. It was discovered by Edwin Hall in 1879.
- Hall Effect is basically the process of development of potential difference across the two faces of a current carrying strip when the strip is kept in a magnetic field.
- The magnitude of voltage depends upon the current, strength of magnetic field and the property of conducting material.
- The Hall Effect is found in conducting material and semiconductor in varying amount depending upon the density and mobility of current carrier.
- The hall effect elements are based on thin film of semiconducting material like indium arsenide.
- The current supply through the lead 1 and 2 and the output is obtained from the strip 3 and 4. The lead 3 and 4 are at same potential when no field is applied across the strip.
- When the magnetic field is applied to the strip, the output voltage develops across the output leads 3 and 4. This developed voltage is directly proportional to the strength of the material.
The voltage is given by
KH= Hall effect coefficient
B= magnetic flux density
t= thickness of the strip (hall element)
The emf produced is called as hall voltage and depends upon the current, flux density and a property of conductor known as Hall effect coefficient (KH).
Advantages of Hall Effect Transducers
- It has long life because no wear.
- They are highly reliable.
- It has very high-speed operation.
- They can be operated in a wide temperature range.
Disadvantages of Hall Effect Transducers
- It cannot measure distance more than 10cm.
- Stray magnetic field can cause inaccurate reading.
Applications of Hall Effect Transducers
- The Hall effect element is used for converting the magnetic flux into an electric transducer.
- The Hall effect element measures the displacement of the structural element.
- The Hall effect transducer is also used for measuring the current without any physical connection between the conductor circuit and meter.
- The Hall effect transducer is used for measuring the power of the conductor. The current is applied across the conductor, which develops the magnetic field.
- Open/close of laptop flip screen. Hence conserve power while switching laptop to sleep.
- Used in encoded switches and rotary encoder.