Re: Magnetic Force with Tesla Coil?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: dave pierson <davep-at-quik-dot-com> 

Tesla list wrote:

>Original poster: "Bob \(R.A.\) Jones" <a1accounting-at-bellsouth-dot-net>
>Hi,
>
>Actually the magnetic field will only penetrate to a skin depth(1/e) of  the
>material at the relevant frequency.   Which in the case of typical Tesla
>coil frequencies is going to be 1mm or less for usually metals including
>ferrous. In addition at typical Tesla coil frequencies phase of the induced
>magnetic field will be such that on average its  repulsive. i.e. the induced
>surface currents shield the bulk of the material. (Lenze's Law).
>
>  However I am not certain why the average force is less compared to the same
>low frequency or dc field.

     The force experienced depends on the material.
     The characteristics of the materials vary with frequency.
      Losses are higher at high frequencies: less force is experienced.

>Presumably at low frequencies or DC the field can
>be increased say a hundred times by ferromagnetic

     The field is what it is (current times turns).
      Ferromagnetic materiasl (If not lossy) will
      concentrate the field in localized areas.
      Air core (as Tesla, typically)  allows the fioeld to spread, and weaken.

      best
        dwp