Even more fun . . . . . although small , the * Rare- Earth * magnets are available at
* Junk - Shack * ( a.k.a. Radio- Shack ) that are the Cobalt type.
 
These will prove that even materials that we consider non-magnetic are subject
to their fields . . . for instance . . . . take a piece ( sheet ) of brass and tilt it at a 45 degree
angle.  Let one of these slide down the sheet and you'll notice that it produces * Eddy *
currents that are strong enough to cause an attraction to the brass .
 
Oh . . . . almost forgot . . . .  .you can use them to erase your PIC  : )
 
        Steve
-----Original Message-----
From: Mike Keitz <mkeitz@JUNO.COM>
To: PICLIST@MITVMA.MIT.EDU <PICLIST@MITVMA.MIT.EDU>
Date: Sunday, September 26, 1999 12:24 PM
Subject: Re: [OT] MAGNETIC FIELDS

On Sun, 26 Sep 1999 10:35:47 -0400 Wagner Lipnharski
<wagnerl@EARTHLINK.NET> writes:
> If you really want to play with magnets, first save away all your
> computer diskettes, then go to a electronic repair shop and buy for
> cents some of the surplus (bad, replaced) Microwave oven MAGNETRON
> valves, dismount the metallic case and you will find one or two very
> (really) powerful circular magnet (axial polarization),

These magnets are really powerful.  Much better than the ones typically
found in loudspeakers.

Of course if you're like me you've played with the magents a little but
are now wondering what's inside the rest of the magnetron.  Here you must
be careful that the ceramic seals of the magnetron (which you'd need to
break to see inside) are not made of toxic BeO.  I kind of doubt it would
be used in a consumer device (except an early model when the magnetron
was really expensive) but if you aren't sure it would be best to throw
away the "heart" of the magnetron without dismantling it further.

and prepare
> to
> have a lot of trouble to separate them if you put two together.

They are made of rather brittle ceramic.  Don't let them crash into each
other or into ferrous metal surfaces as they probably will break.

Even more powerful, though small, magnets can be found in hard disk
drives which are new enough to use a voice coil instead of a step motor
to move the head.  The magnets are found inside the disk cover,
suprisingly close to the disk, on the back end of the arm that holds the
heads.



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