Re: Platinum 5.25" drive problem

[mjmahon@aol.com (Michael J. Mahon)]

william strutts asked:

>"Michael J. Mahon" <mjmahon@aol.com> wrote in message
>20010801122624.16450.00003887@ng-mq1.aol.com">news:20010801122624.16450.00003887@ng-mq1.aol.com...
>
>> In fact, the degree of magnetization of _anything_ is limited by its
>> magnetic properties, and not by the strength of the magnetic field
>> magnetizing it.  Once the material is saturated in some alignment,
>> then additional field strength does nothing.
>>
>
>Does this have something to do with the hysteris loop?

Exactly.

"When a material is magnetized by an outside supplied field which is
alternating in direction, the graph of the induced field when taken to
saturation in both directions forms a symmetric loop. The loop is
called a hysteresis loop."

The typical shape of a hysteresis loop, superimposed on
axes (whose origin is the middle "+") is:

                   |
                ---+-----------------
               /   |       /
              /    |      /
-------------/-----+-----/---------------> H
            /      |    /
           /       |   /
  -----------------+---
                   |

(looks best in fixed-pitch font)

The horizontal axis is H, the magnetizing field, and the vertical
axis is B, the field induced in the magnetic material.  Note that
as H varies in sign and magnitude, B saturates at symmetric
positive and negative values.  So applying more H than is needed
to saturate the material does not increase the induced field, B.

-michael

 Email:  mjmahon@aol.com
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