RE: TC Optimum Coupling

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "John H. Couture by way of Terry Fritz <twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>


Antonio -

The JHCTES program appears to conflict with what Marco said about the K
Factor. I wanted to point out that the program is correct when it shows that
the secondary voltage (spark length) increases and the K Factor decreases
when the secondary windings are increased. This obviously can not be
extended beyond a certain amount because the secondary voltage would go to
infinity as the K Factor is decreased. For this reason I set a limit on the
number of secondary turns for the program.

To my knowledge no one has ever made the necessary tests to determine the
increase in secondary volts when the K Factor is increased by reducing the
clearance between the primary and secondary coils. These tests would be of
interest to find out how the secondary voltage conforms with theory. In fact
this would be important information because coilers change the pri/sec
clearance by raising the secondary coil. How much secondary voltage are they
loosing when they do this?

John Couture

------------------------------


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Friday, August 30, 2002 7:02 PM
To: tesla-at-pupman-dot-com
Subject: Re: TC Optimum Coupling (was RE: Auto Quenching - OOPs!! forget
that one ;-)


Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:
>
> Original poster: "John H. Couture by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
>
> Terry, Antonio, Marco, all -
>
> Tesla coil theory and simulations must be used with caution. Increasing
the
> K factor of Tesla coils can increase the secondary volts output? Reducing
> the number of secondary turns can increase the K Factor. If you continue
> with this reasoning you might believe that you could use only a few
> secondary turns for big sparks or secondary voltages. See below.

The increase in k increases the output voltage -if- it can be increased
without changing the primary or the secondary coils, and the system is
correctly tuned. The increase os just due to faster energy transfer,
with less time for energy dissipation in the various losses of the
system. With fixed inductances and correct tuning, the maximum voltage
gain is fixed as sqrt(L2/L1) (or, more exactly, sqrt(C1/C2), because
it's possible to exceed the former by a small margin detuning the
system) for any value of k, if all the losses are negligible.
To increase k by decreasing L2 usually decreases the gain, although in
some very lossy systems some gain can, apparently, be obtained.

Antonio Carlos M. de Queiroz