Re: tesla coil power ?! (fwd)

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Original poster: Steven Roys <sroys@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Thu, 27 Sep 2007 08:02:32 -0400
From: Dave Pierson <davep@xxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: tesla coil power ?! (fwd)

Random comments
(arguably this could go on the Tesla Coil list.)

1) There is nothing particularly strange about 'nearby' coils
   sparking.  Conventional physics covers it nicely.

2) Similarly with sparking 'from feet'.  In reading of operators
   at high power radio stations (bigger than 50 KW) it was
   Standard, when out around a live antenna to 'jump' to/from
   trucks to avoid getting zapped by strays.  The truck would
   make one plate of a cap, the local ground the other and the RF
   appears as highish voltage between.  Some combination of
   inductive and capacitive coupling does nicely, all quite
   conventional.

3) I would not, for what its worth, invoke 'Yagi' principals
   at usual Tesla coil freqs.  Yagi design technique is for
   (roughly) 1/8 or so wave from driver to other elements.
   (cf any antenna design text.)  At the usual coiling freqs
   thats 100s of meters...  I would expect (as above) that 
   adding coils, or other conductors, spaced from 'driver'
   coil to 'receiver' coil migh show 'directionality' by
   setting up a 'chain of series capacitors' with lower loss
   along the chain.  And, if the objects be coils, and at
   common resonant frequency, the coupling may be inductive as
   well.  Again, quite conventional.

   best
    dwp