Jerry wrote:
> On Jul 27, 9:28 am, jim <j...@[EMAIL PROTECTED]
> wrote:
>> I need some help in locating ceramic disc magnets that measure 120mm in
>> diameter with no hole in the center. The thickness can be as much as
13 mm
>> 25.4mm.
>>
>> The strrength is not as im****tant as the dimensions and that it be a
solid
>> disc (no hole in center).
>>
>> I have found neo magnets that are up to 8" in diameter, but their
strength
>> will actually make it more difficult to perform the initial experiment.
>>
>> If anyone knows where I may purchase ceramic desci magnets that are at
least
>> 120mm in diameter and up to 25.4mm in thickness, with no holes in them,
>> please let me know.
>>
>> Thank you for your help.
>>
>> (I have Googled, Ask'd, Yahoo'd, etc. - all to no avail. The magnets
that I
>> have found generally top out at 76mm in diameter. If I have missed
>> something in these searches, I would appreciate someone pointing it
out.)
>
> I suspect that you are asking the wrong question. I suspect that
> your REAL question is, how can you create a close approximation
> to a uniform magnetic field over an area of many square
> centimeters.
Not really. A ceramic disc's magnetic flux lines (assuming they eminate
from the ends and have only a single set of poles) are not uniform in
strength. There is a definite pattern to the magnetic field lines that
you can easily see when you do the old iron filings on paper over a bar
magnet made from a cylinder.
A uniform magnetic field may be fun to play with, but would not
approximate the magnetic flux line pattern found at the poles of ceramic
or neo disc magnets.
>
> The answer WON'T be by using a large monolithic hunk of ceramic.
> Inevitable nonuniformities in manufacturing that arise during
> the magetization step mean that the strength of field will vary
> considerably between center and edge of the disc.
Yes they will. I never asked for a uniform magnetic flux field for
testing.
> Instead, consider a large array of carefully matched magnets
> faced off by pole pieces.
>
> Why don't you share your actual requirements with us, rather
> than trying to be so secretive about the experiment that you
> intend to perform?
For 2 reasons... (1) If I am onto something, revealing what little I
know without a reliable means of reproducing the effect for the
scientific community would only serve to confuse the issue and start
debates that will waste time and not answer the questions that I can
answer with a few simple experiments. (2) If I am wrong, revealing the
goals, theories and suppositions of the experiment may make me look
foolish. Why do that when I can simply experiment, learn and grow in
wisdom without the public humiliation of trying an experiment that may
have flaws that are not obvious to me at this time.
I know of no better way to learn something than to do it for yourself.
Reading about things is only memorization. True learning comes from
doing.
IMHO, it is wise to say as little as possible when it comes to theory
and experimentation until such time as you have answers that can be
objectively proven via scientific experiments by others - independent of
your help.
Thanks for your posts.
jim
|
