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Power-User

Join Date: Nov 2009
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Where are Rare Earth Magnets Located in Computers?

12/13/2009 9:00 AM

In recent news articles about rare earth magnets they state that these magnets are essential for use in computers and wind turbines etc.

I have a few old computers at home - can anyone tell me whereabouts inside a computer I can find these rare earth magnets?

I assume they might be in the hard disk drive or the power supply but i would prefer to know for sure before trying to find them.

Thanks for your help.

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Guru

Join Date: Oct 2008
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#1

Re: Where are Rare Earth Magnets Located in Computers?

12/13/2009 9:13 AM

Motors and generators are where you'll find them. And maybe in the read head of your hard drive. Rare earth magnets can be much smaller than alnico of ferrite magnets.

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Guru

Join Date: Mar 2007
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#2
In reply to #1

Re: Where are Rare Earth Magnets Located in Computers?

12/13/2009 10:14 AM

I have some doubts that the read/write head of a HDD is equiped with a PM.

As far know the head is a miniature coil used to polarize the material of the disc by writing and to get the pulse geberated by the polarized disc island by readind. But of course as usual I may be wrong.

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Anonymous Poster
#3

Re: Where are Rare Earth Magnets Located in Computers?

12/13/2009 11:59 AM

the rarearth magnets are in the hard drive. they control the swing arm upon which the read-heards are located. ...---Benbenben

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Guru
Engineering Fields - Electrical Engineering - Analog and Digital Circuit Design Engineering Fields - Electromechanical Engineering - Transformers, Motors & Drives, EM Launchers Engineering Fields - Engineering Physics - Applied Electrical, Optical, and Mechanical

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#4

Re: Where are Rare Earth Magnets Located in Computers?

12/14/2009 12:30 AM

Benbenben's got it. Moving coil motor with RE magnets moves HDD swing arm which has the read/write heads at the far end. I believe the platter spin motor (brushless DC) may also contain small RE magnets.

********** DON'T TAKE APART A GOOD DRIVE! *************

If you have an old HDD which is toast, take it apart to see how it works. RE magnets are very powerful so be careful. For a real treat, take a look at the read/write heads under a microscope.

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Guru

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#5

Re: Where are Rare Earth Magnets Located in Computers?

12/14/2009 7:17 AM

Yes, controlling the read write head in HDDs

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Commentator

Join Date: Dec 2006
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#6

Re: Where are Rare Earth Magnets Located in Computers?

12/14/2009 7:25 AM

You will also find a set in your CD/DVD player/burner. Back when I was doing audio repair I had dozens holding notes up over my bench.

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