Re: Displacement Current Revisited

  Ed -

  I also wondered about the compass test. However, Tesla said the RF sine
wave from the TC is not symmetrical so it would affect the compass if the
field was strong enough. To my knowledge no one has ever made this test. A
Hall effect IC could also be used. This test might also be a good tuning test. 

  I agree a preliminary test of only the secondary could be made by running
a small DC current thru it. This would give some idea of how nuch current
would be required to deflect the compass and how to best align it.  

  Apparently the induction field falls off inversely as the cube and the EM
field falls off inversely as the square of the distance.

  John Couture


At 10:42 PM 3/21/99 -0700, you wrote:
>Original Poster: Ed Phillips <evp-at-pacbell-dot-net> 
>"  Coilers are apparently not familiar with the induction field around
>Tesla coil. If I understand this field correctly a coiler should be able
>detect the field with a compass placed near a TC while it is energized.
>compass is not sensitive to the EM field but should deflect because of
>magnetic effect of the induction field. The compass would have to be
>properly aligned and very close to the center of the secondary winding.
>anyone tried this test? Reinhart's lamp could be used but this is also
>sensitive to the EM field.
>  John Couture"
>        For this test you'd want to run a small DC current through the coil.
>Field falls off inversely as the cube of the distance.