Degaussers Presentation by Ben Sheron Daniel Pulito Jeffrey Abbott Ryan Toukatly
History � Term ”degausser” first coined by Cmdr. Charles Goodeve in WWII � Navy ships would become magnetized while traveling through the earth's magnetic field � In addition to causing problems with compasses and other navigational equipment it put the ship at risk of setting off German mines � Goodeve devised a simple coil system to cancel out the ship's magnetic field
Theory � In applications such as CRTs a deguasser generally consists of a coil along with a thermister � As the coil heats up, so does the thermister � The resistance increases, decreasing the current as well as the magnetic field
Theory
Theory μ ˆ μ I NI = = 0 0 ˆ B a B a φ 2 π z r l Magnetic caused by straight Magnetic caused by current line of current through a coil, a solenoid
Theory Magnetic dipoles in magnetic material Magnetic field aligns the magnetic dipoles in the same orientation Magnetic dipoles after Degaussing has occurred
Applications � Naval ships � CRT monitors � Erasing data by randomizing the domains on magnetic media such as hard disk drives and magnetic tape � In some cases the degausser is used to destroy the media permanently
Sources � http://www.gaussbusters.com/ppm93.html � http://www.vectorsite.net/tpqm_04.html � http://www.epcos.com/inf/55/db/ptc_06/Degaussing __Double__Mono__T__B59______T.pdf � http://en.wikipedia.org/wiki/Degaussing
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