Tesla Coil Operation (was -Wire length,resonance, and Q)

From:  John H. Couture [SMTP:couturejh-at-worldnet.att-dot-net]
Sent:  Monday, May 25, 1998 1:31 PM
To:  Tesla List
Subject:  Re: Tesla Coil Operation  (was -Wire length,resonance, and Q) 

  Bill, All

  The answer to your question about transferring energy from the TC pri coil
to the sec coil is in the understanding of magnetic circuits (not
magnetism). Coilers are familiar with electric circuits governed by Ohm's
law but not magnetic circuits which are governed by a different law. These
two basic circuits of electricity have completely different characteristics.
The most astounding difference (usually taken for granted) is that electric
circuits have losses while magnetic circuits do not.

  It is obvious that to completely understand how a Tesla coil works you
must understand both electric and magnetic circuits. Ohm's law is  Volts =
Currents times Resistance. Losses (heat) are due to currents flowing thru
resistances. The Ohm's law of magnetic circuits is  Magnetomotive Force =
Magnetic Flux times Reluctance. Note that currents and resistance are not
involved in this equation so there are no losses.

  The magnetic energy in the pri coil is transferred to the sec coil with no
losses and with 100% transfer. This means energy is transferred thru space
filled only by magnetic fields and without conductors. This is normally
taken for granted today but imagine Faraday's and his contemporaries
surprise when they found this new discovery. Note that this is not the same
as electromagnetic radiation energy thru space (radio, etc) that was
discovered later.  
  Only coilers and others who understand completely how a Tesla coil works
will be able to explain why the 100% transfer is possible in spite of
hysteresis, eddy currents, leakage flux, etc,

  There is much more to this story but you will have to consult many books
to find the answers because no single book contains the complete story.

  John Couture


At 09:17 AM 5/23/98 -0600, you wrote:
>---------- Forwarded message ----------
>Date: Sat, 23 May 1998 05:19:28 PDT
>From: Bill the arcstarter <arcstarter-at-hotmail-dot-com>
>To: couturejh-at-worldnet.att-dot-net, tesla-at-pupman-dot-com
>Subject: Re: Wire length,resonance, and Q (fwd)
>Hi John.
>It was written:
>>  Jim, Malcolm, All -
>>  It should be noted that electromagnetic fields (Hertzian waves) 
>>propagate at the speed of light. This is not true of electric or 
>>magnetic fields which are perpendicular to the direction of 
>>propagation of electromagnetic fields. This confuses coilers and many 
>>others the same as the fact that energy transfer by magnetic 
>>induction is always at 100% transfer. Tesla said that his TC did not 
>>operate with Hertzian waves.
>>  John  Couture
>OK - I'll bite.  100% is always a bold statement to make about most 
>anything, including energy transfer...  :)
>Are you talking about transferring energy from coil #1 to coil #2?  Or 
>are you speaking of storing (and subsequently extracting) energy from a 
>single coil? 
>I am not an expert on transmission line theory or even general e-mag 
>principles.  Any clarification on your use of "100%" would be 
>-Bill Pollack (arcstarter)
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