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


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From:  John H. Couture [SMTP:couturejh-at-worldnet.att-dot-net]
Sent:  Thursday, May 28, 1998 11:44 PM
To:  Tesla List
Subject:  Re: Tesla Coil Operation  (was -Wire length,resonance, and 


  Malcolm, Terry -
  
  True, a Tesla coil does not operate at 100 % overall efficiency, input to
output. However, I was referring only to the transfer of energy from the TC
pri coil to the sec coil. This energy transfer is not by an electric circuit
but by a magnetic circuit (induction) and at 100 % transfer with no magnetic
energy losses.

  With resistance in the coil wiring, hysteresis, eddy currents, and leakage
flux all cause losses but this does not change the 100 % energy transfer by
induction.

  If there is no resistance in the coil wiring (super conductors) the energy
from the pri coil input to the sec coil output is transferred at 100 %
overall efficiency.

  Terry, nearby objects stealing magnetic flux is an interesting thought.
This would be inductive heating and the losses would be 100 %. Also, the
magnetic energy in the coil would be transferred through the insulation and
air to the object, etc, by induction and at 100 % transfer. However, the
heating of the object would be at less than 100 % overall efficiency.
Talking about the efficiency of a process can get confusing.

  John Couture

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At 11:16 PM 5/27/98 -0500, you wrote:
>
>----------
>From:  terryf-at-verinet-dot-com [SMTP:terryf-at-verinet-dot-com]
>Sent:  Wednesday, May 27, 1998 12:07 PM
>To:  tesla-at-pupman-dot-com
>Subject:  Re: Tesla Coil Operation  (was -Wire length,resonance, and 
>
>John, Malcolm,
>
>>
>>----------
>>From:  Malcolm Watts [SMTP:MALCOLM-at-directorate.wnp.ac.nz]
>>Subject:  Re: Tesla Coil Operation  (was -Wire length,resonance, and 
>>
>>A comment:
>>
>>> 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) 
>> 
>><snip>
>>>   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,
>>
>>I am bound to say that those of us who have approached that level of 
>>understanding know why that statement is not true. Our test gear 
>>tells us it's not as well.
>>
>>Malcolm
>>
>
>Obviously, no one has a Tesla coil that operates at 100% efficiency.  I
>think John was trying to point out that all the losses are due to resistive
>effects from I^2R losses.  If one uses none magnetic materials the
>hysteresis loss should go away.  In free space the magnetic fields would
>tend to stay in the coils.  Consider a coil that has no resistance (perhaps
>super cooled), no breakout, and no nearby objects to steal magnetic flux.
>Would such a coil run forever once triggered?  Perhaps a long time.  The AC
>fields generate forces inside the inductors which move and contract them
>slightly and do real work with each cycle. There are also dielectric losses
>especially in the capacitors that would still be a factor.  John may
>consider these as I^2R losses or perhaps super cooling would eliminate this.
>Of course, the plasma inside a conventional spark gap would need to be
>eliminated too.
>
>        Given a charged primary cap, can one get 100 percent of the energy
>into the secondary capacitance with 100 percent efficiency.  Not in the real
>world...  Can the secondary pick up 100 percent of the primary's flux that
>is available.  No. but it can get very close in a very special setup.  
>
>My $0.02 worth.
>
>        Terry Fritz
>
>
>