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Re: Magnets



Original poster: Ed Phillips <evp@xxxxxxxxxxx>

Original poster: gary350@xxxxxxxxxxxxx

Did anyone see the TV show a few months ago about magnets. They said, there was not much known about magnets 40 years ago they were not considered very useful. Magnet technology has increased 30 fold in the past 10 years and now have 1000s of applications. Has any research been done with magnets on a Tesla Coil?"

That TV show was putting out pure uninformed nonsense. Magnets (I assume you mean permanent magnets as electromagnet have no mysteries at all) have been thoroughly understood even at the theoretical level for at least 100 years and used by the billions over the years. Just about every speaker in every radio built since 1940 (and many before that) uses permanent magnet field structures and ALL telephone receivers ever built from the first Bell one on used permanent magnets in the receivers.

What has happened in the past 40 years that a number of new permanent magnet materials have been developed which offer greater energy in a given volume and their price has become reasonable. At one extreme are the ubiquitos ceramic magnets which have low energy but are dirt cheap and at the other would be the NdFeB magnets which have far more energy and are now quite affordable.

Ed