2. CONTENTS
Hall Effect
Discovery of Hall Effect
Theory
Lorentz Force
Hall Voltage and Hall Coefficient
Significance
Applications
3. Hall effect
Hall effect is the production of voltage difference (Hall
voltage) Across a current carrying conductor In the presence
of magnetic field Perpendicular to both Current and
magnetic field
4. Discovery of hall effect
Hall effect was discovered by Edwin
Herbert Hall in 1879 while he was
working on his doctoral degree At Johns
Hopkins university in Baltimore, Mayland
Hall effect was discover by Edwin Hall
eighteen years before discovery of
electron.
5. Theory:
The quality of the current present in the conductor is reason of Hall
effect to produce. Current is composed of movement of small
particles that are free to move such as electrons holes and Ions
When the current carrying conductor is placed in the magnetic field
,Voltage will be generated Perpendicular to both current and Field.
In the presence of magnetic field these free particles produce
Lorentz Force.
6. Lorentz force
Lorentz Force is exerted on electrons Due to which
electron moves in direction perpendicular to both Current
and magnetic field. This will develop a voltage difference
across conductor
Lorentz force is equal to
F= q(E+v×B)
7. Hall voltage and hall coeffiecient:
Internal electric potential known as Hall voltage and is given
by the formula
Vh = (Ix)(Bz)/nte
Hall coefficient is defined as:
The ratio of the Induced electric field To the product of
current density and magnetic field that is applied
Rh=Ey/(Jx)(Bz)
Where Jx is the current density and Ey is the Electric
field
Unit of Hall coefficient is Mete cube per coloumb
8. Significance:
Hall effect Describes an important Difference between
positive and negative Charges that is positive charges will
move in one direction NAD negative charges will move in
opposite direction of negative charges
Hall effects proves that Current in the metals produced due
to the motion of electrons
9. Applications of hall effect
Hall Effect devices generate a very low signal level .
Therefore, they need amplification. And it is very suitable
for instruments in laboratory.
The vacuum tube amplifiers in the 1st half of 20th century
were power intense, very costly and erratic for everyday
use in applications. This has done by the generation of low
cost IC’s. And the sensor based on Hall Effect became
appropriate for mass applications.
Most of the devices are now sold as “Hall Effect Sensors”.
Another application of Hall Effect is “Hall Effect IC” that use
electrical motors of switch.
10. Some important Applications of Hall Effect are:
Split Ring Clamp-on Sensor
Analog Multiplication
Power Sensing
Position and Motion Sensing
Automotive Ignition and Fuel Injection
Wheel Rotation Sensing
11. Daily – life Applications
The Corbino Effect
Hall Probes
Magnetometer
Hall Effect Sensors
Vacuum Tube Amplifiers
Microcontroller
Integrated Circuits
12. Split Ring Clamp-on Sensor
A split sensor is used in the variation on the ring
sensor that is clamped over the line to make the
device able to be used in temporary test equipment.
If it is used in installation that will be permanent,
then a split sensor permits the electrical flow of
current to be tried without disassembling the current
circuit.
13. Analog Multiplication
In Analog Multiplication, the output is proportional to both
the applied sensor voltage and the applied magnetic field. If
we apply the magnetic field by a solenoid, then the output
of sensor is proportional to product of the current through
the solenoid and the sensor voltage.
As most applications requiring computation are now
performed by small (even tiny) digital computers, the
remaining useful application is in power sensing, which
combines current sensing with voltage sensing in a single
Hall effect device.
14. THE CORBINO EFFECT
The Corbino effect is a phenomenon based on the
Hall Effect, but a disk-shaped metal sample is used
in place of a rectangular one.
15. HALL EFFECT SENSOR
A Hall Effect sensor may operate as an electronic switch;
Such a switch costs less than a mechanical switch and is
much more reliable.
It can be operated at higher frequencies than a mechanical
switch.
It does not suffer from contact bounce because a solid
state switch with hysteresis is used rather than a
mechanical contact.
16. Linear sensor
In the case of linear sensor (for the magnetic field
strength measurements), a Hall Effect sensor:
can measure a wide range of magnetic fields
is available that can measure either North or South
pole magnetic fields
can be flat
