Edwin Hall

Personal Background

Edwin Herbert Hall was born in Great Falls, ME on November 7, 1855 to Joshua Emergy Hall and Lucy Ann Hilborn Hall. He got his primary education at the local district school and prepared for college by attending "Gorhma Seminary" for two years. Before Hall was 16, he got into Bowdoin College in Brunswick, Maine and graduated as valedictorian of his class in 1875 with a Bachelor of Arts degree. After graduation, he served as principal of Gould's Academy in Bethel, Maine from 1875-1876,and he served as principal of Brunswick High School in Brunswick, Maine from 1876-1877. After two years of teaching, he decided to further study physics, and in the fall of 1877, he entered Johns Hopkins University as a graduate student in physics. He wrote, "I should perhaps have studied law, if I had not felt myself unfitted to advocate a cause in which I did not believe. I turned to science, after two years of school teaching, because it was progressive and satisfied my standards of intellectual and moral integrity, not because I had any passionate love of it or felt myself especially gifted for scientific undertakings."While working under Henry Augustus Rowland, he discovered the Hall Effect in 1879. In 1895, he became a physics professor at Harvard and worked until his retirement in 1921.He died on November 20, 1938.

Scientific Contribution

Hall Effect

When a magnetic field is applied to a conductor or a semiconductor, electromotive force (EMF) is created perpendicular to the direction of the current and the magnetic field. This phenomenon is related to the moving charge in the current. The magnetic field that is perpendicular to the current-carrying wire makes the moving charge go to one side due to the Lorentz Force.

Industrial Contribution

Hall Effect Sensor

What is the Hall Effect Sensor?

A device that changes its output voltage depending on the intensity of the magnetic field. It is based on the Hall Effect.

How does it work?

Even if the current runs in the same direction, depending on the sign of the moving charges, the direction of the created electric field can vary. Also, the intensity of the electric field changes in response to the density of the moving charges. Using these phenomena, the intensity of the current-carrying moving charge in a solid can be measured, and in a semiconductor, the free electron can be identified

The usage of the Hall Sensor

Sensing the continuous current Sensing the alternating current Measuring the intensity of the magnetic field Detecting the polarity of the current Sensing temperature by detecting the intensity of the magnetic field in the Ferrite-Magnet

See also

Are there related topics or categories in this wiki resource for the curious reader to explore? How does this topic fit into that context?

Further reading

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External links

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References

https://www.grc.nasa.gov/www/k-12/airplane/thermo0.html http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/thereq.html