Degaussers Presentation by Ben Sheron Daniel Pulito Jeffrey - - PowerPoint PPT Presentation

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

• ut 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

r I a B π μ

φ 2

ˆ = l NI a B

z

ˆ μ =

Magnetic caused by straight line of current Magnetic caused by current through a coil, a solenoid

Theory

Magnetic dipoles in magnetic material Magnetic field aligns the magnetic dipoles in the same

• rientation

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