Re: How to rise the secondary? (fwd)

---------- Forwarded message ----------
Date: Fri, 24 Jul 1998 21:54:54 +0000
From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: How to rise the secondary? (fwd)

  Bart, All -

  Is "just beyond arc-over" important with coupling which only affects the
time of energy transfer? Coupling does not affect the amount of energy
transferred, therefore, going beyond the arc-over point would not affect
spark length.

  Theoretically you could go a 10 ft beyond the arc-over point and it would
only take more time to transfer the energy and would produce the same spark
length. However, if the tuning is inseparable from the coupling then there
would be a reduction in spark length because tuning affects the amount of
energy transferred.

  Some coilers have mentioned the fact that the current losses would
increase with the increase in transfer time and this is correct because
losses involve time for currents to pass thru resistances. It is obvious,
therefore, that to keep losses at a minimum the coupling does not have to be
precise but be close enough so that the losses are negligible.   However,
the tuning must be precise to get 100% magnetic energy transfer.

  I believe the above answers the question about "raising the secondary".
For example, there will always be more flux linkages between the primary and
secondary coils  when the bottom of the secondary is level with the primary
spiral. Moving the secondary away from the primary will only reduce the
linkages and shorten the spark.

  "Quenching is providing an energy transfer". This sounds like you are
confusing quenching with "spark duration" which involves the amount of time
that energy is transferred. Quenching is only the action of turning off the
spark which brings up more questions.

  There have been hundreds of articles in the past that have tried to
explain how a Tesla coils works. All of these articles ignore many details
that indicates we still have a lot to learn about Tesla coil operation and
design. When it comes to magnifiers we are only in a primitive testing stage
so empirical design is not possible. It could turn out that when we learn
how to design the optimun classical Tesla coil the magnifier will not be

   John Couture


At 10:33 PM 7/20/98 -0600, you wrote:
>Content-Type: TEXT/PLAIN; CHARSET=us-ascii
>Content-ID: <Pine.LNX.3.95.980720223312.30930Z-at-pupman-dot-com>
>---------- Forwarded message ----------
>Date: Mon, 20 Jul 1998 22:51:45 -0500
>From: "Barton B. Anderson" <mopar-at-uswest-dot-net>
>To: Tesla List <tesla-at-pupman-dot-com>
>Subject: Re: How to rise the secondary? (fwd)
>John, All,
>Your right. The big question is if the design to "just beyond arc-over" vs
>secondary" increases spark length, etc.. I don't know. Guess more
"emperical data"
>is necessary.
>My post was an extreme laymans term of what is theory. You may be correct
in all
>your comments. I would be the first to admit I know little of the coupling
>such coils. I was trying to relate coupling to the field of flux and how
the aircore
>coil is receiving this field.
>TC tuning has always been (in my mind) tuning a primary to the resonant
frequency of
>sec. Coupling has always been a flux of one coil linking another coil, i.e.,
>coefficient of coupling is a fraction or ratio of total flux that can be
>Comments intersperced below,
>Tesla List wrote:
>> ---------- Forwarded message ----------
>> Date: Sun, 19 Jul 1998 06:07:34 +0000
>> From: "John H. Couture" <couturejh-at-worldnet.att-dot-net>
>> To: Tesla List <tesla-at-pupman-dot-com>
>> Subject: Re: How to rise the secondary? (fwd)
>> 2. Undercoupled (too far away) not enough current, etc. - There is no
>> current to transfer energy from the pri to sec coil, only magnetic flux.
>> There is never any loss of magnetic flux when transferring energy between
>> the coils. Why?
>True, but magnetic flux is produced by current in the primary coil, and the
>field of flux is directly proportional to current which is producing it. The
>transfer of magnetic flux is the real question. Yes, magnetic flux transfer
>energy transfer, but it is the coefficient or fraction of magnetic flux that is
>transferred which equals or relates to the coefficient or fraction of energy
>transferred. Loss is only in a load or current producing heat of some
proportion in
>an inductor regardless of what (or where) that inductor may be. As far as
"there is
>never a loss of magnetic flux", that's true of what we are transferring. If we
>transfer a coefficient of .3, then we get 100% of .3, or 30% of the total flux
>produced. What happens if we could transfer at unity coupling? So far that
>possible in an aircore inductor.

>> 4. K beyond our reach -Quenching is not energy transfer. Quenching is
>> turning off the operating spark, preferably at the right time.
>Yes, but quenching is providing an energy transfer of current in a given
amount of
>time vs. a given amount of current in say double or tripple time which reduces
>energy transfer per time interval. In other words, the coil reacts to 1
second of
>energy better than 3 seconds of the same energy, or better yet, three times
the work
>in the same amount of time.

>>   6.  Spice is a program that uses theoretical electronic equations. If it
>> was "to shape the em field" without empirical data it would not conform to
>> real world coils. Like trying to find the true capacitance of a toroid on
a TC.
>True. But, a measure of real world coil to theoretical coils is interesting
as it
>proposes questions of "why did this "not" do that"? Well worth the fun and
adds to
>the enlightenment of us all. Maybe there's another program for em field
>I'm not aware of?John, thanks for the reply. BTW, do not "give in to criticism"
>until you yourself are convinced. I've always enjoyed your posts and look
forward to
>your comments.
>Best regards,
>>    John couture