1. EDWIN HALL
Born on: november 7 th 1855
Died the: november 20 th 1938
He was an American physicist who
discovered the eponymous Hall effect.
Hall conducted thermoelectric
research at Harvard and also wrote
numerous physics textbooks and
laboratory manuals.
2. BIOGRAPHY
Edwin Herbert Hall was born in Great Falls (later North
Gorham), Maine, and educated at Johns
Hopkins University, Baltimore. He discovered the
“Hall effect” in 1879 while working on his doctoral thesis
in Physics under the supervision of Professor Henry
Augustus Rowland.
After a year in Europe, Hall joined the Harvard faculty and
was appointed professor of physics in 1895, a post he
held until his retirement in 1921. He continued his
thermoelectric research at Harvard, where he also wrote
numerous physics textbooks and laboratory
manuals. Hall spent much of his later life attempting to
measure the various effects as exactly as possible.
Edwin Hall died on November 20, 1938, in Cambridge U.S.A.
3. THE HALL EFFECT
The Hall effect is the production of a voltage difference
(the Hall voltage) across an electrical conductor,
transverse to an electric current in the conductor and to
an applied magnetic field perpendicular to the current. It
was discovered by Edwin Hall in 1879. For clarity, the
original effect is sometimes called the ordinary Hall
effect to distinguish it from other "Hall effects" which
have different physical mechanisms.
The Hall coefficient is defined as the ratio of the
induced electric field to the product of the current
density and the applied magnetic field. It is a
characteristic of the material from which the conductor is
made, since its value depends on the type, number, and
properties of the charge carriers that constitute the
current.
4. CURIOSITY ABOUT THE HALL EFFECT
The “Hall effect” remained a laboratory curiosity until the
latter half of this century because materials available
prior to recent years only produced low levels of Hall
voltage. With the advent of semiconductor technology
and the development of various III-V compounds, it
became possible to produce Hall voltages many orders of
magnitude greater than with earlier materials.
Thus, semiconductor technology launched the practical
design and production of the Hall sensor.The Hall effect
is commonly used to control the primary circuit of
an electronic ignition system.The principle is used in
Hall effect crankshaft position sensors and
ignition pickups is to produce a very clean on-off signal.
5. THE END
Work made by: Colangelo Matteo and Di Nisio Leonardo
Class: 5°G
