Re: How to rise the secondary? (fwd)
Your right. The big question is if the design to "just beyond arc-over" vs "raising
secondary" increases spark length, etc.. I don't know. Guess more "emperical data"
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 between
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 linked.
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)
> 1. "Undercoupled - there is less energy transferred". This is contrary to
> theory. However, coupling and tuning may be inseparable and tuning affects
> energy transfer. (I'm giving in to my critics).
Coupled = linking of flux. Undercoupled = less linking of flux. Power is 100%, but
energy? Undercoupled or "loose coupling" can also be thought of as a low
coefficient. In other words, current in coil A induces "less" voltage in coil B. In
our case, less voltage in coil B = less spark length (or does it?).
> 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 magnetic
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 equals
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 isn't
possible in an aircore inductor.
> 3. Favorably coupled - what is the relationship between coupled,
> current, and quenching? Equations?
I think you hit the nail on the head here. Equations? No, I am not Mr. equation, but
it doesn't take a rocket scientist to see that coupling, current, and quenching all
equate to favorable or poor energy transfer.
> 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.
> 5. I agree there are no programs that take into account sparkgap
> quenching. But I don't agree that coupling is a hit or miss condition.
> Otherwise those "raising the secondary" precise adjustments that coilers are
> talking about are not precise. Proper coupling to prevent sparkovers can be
> determined by following what coilers have done in the past.
Who says their precise? Anyway, raising the secondary may be a minute adjustment
compared to current or Lp to Ls distance. I agree that coupling to prevent
sparkovers can be ballparked by following what coilers have done in the past, but I
think there is more to coupling than I know or most coilers for that matter, even
the equation enthusiastic coilers. BTW, love equations. But, coupling is the
mechanism we must understand. How can we design coils without understanding the
role coil A plays on coil B magnetically, at least, to the precision you've
proposed? Not quite there yet and I think you and most would agree.
> 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 probagation
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
> John couture
> At 01:50 PM 7/18/98 -0600, you wrote:
> >---------- Forwarded message ----------
> >Date: Sat, 18 Jul 1998 10:00:03 -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,
> >Coupling is two-fold. First, coupling is a coefficient of magnetic flux linking
> >inductors resulting in some amount of energy transfered.