A Faraday wheel is an early homopolar generator invented by Michael Faraday. The Faraday Wheel uses the Lorentz forces created by electrons moving azimuthally through a magnetic field to create a potential difference between different points on the radius of the wheel. The Faraday wheel was one of the first examples of a magnetic field being used to produce electricity.
A homopolar generator is a DC electrical generator comprising an electrically conductive disc rotating in a plane perpendicular to a uniform static magnetic field. A potential difference is created between the center of the disc and the rim, the electrical polarity depending on the direction of rotation and the orientation of the field. It is also known as a unipolar generator, acyclic generator, disk dynamo, or Faraday disc. The voltage is typically low, on the order of a few volts in the case of small demonstration models, but large research generators can produce hundreds of volts, and some systems have multiple generators in series to produce an even larger voltage. They are unusual in that they can source tremendous electric current, some more than a million amperes, because the homopolar generator can be made to have very low internal resistance.
Famous quotes containing the word wheel:
“Of the wheel as it rolls unrelentingly over
A cow plodding through car-traffic on a street in Iasi,
And over the haunts of Robert Pinsky’s mother and father
And wife and children and his sweet self”
—Robert Pinsky (b. 1940)