Re: Practical limit to number of turns on primary ? ? ?

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

Original poster: "Jolyon Vater Cox by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>

I too am intrigued by emphasis on turns rather than relative impedance of
primary and
secondary.
According to theory would it not be possible to get a voltage step-up using
a
secondary with same number or fewer turns than the primary if only the the
secondary
inductance were greater; this of course would require a wider diameter on
the
secondary with respect to the primary so perhaps coupling would suffer.
Therefore,
could it be the larger number of turns normally used on TC secondaries is
nothing
more than a "necessary evil" to ensure that there is adequate coupling
between primary
and secondary windings -a coincidence which distracts from the fact that it
is the impedance ratio -not the turns ratio- that is responsible for the
voltage increase observed in Tesla coils?

Jolyon.

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, January 27, 2003 4:44 AM
Subject: Re: Practical limit to number of turns on primary ? ? ?


 > Original poster: "Malcolm Watts by way of Terry Fritz
<teslalist-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>
 >
 > Hi Dan,
 >
 > On 26 Jan 2003, at 19:59, Tesla list wrote:
 >
 >  > Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>"
 > <dhmccauley-at-spacecatlighting-dot-com>
 >  >
 >  > Through your tesla experiences, what is the practical limit to the
number of
 >  > turns on a primary before efficiency and performance begins to suffer?
 >  >
 >  > I personally have not built a primary with more than 16 turns, and it
seems
 >  > most have not built tesla coils with greater than 16 turns and most of
the
 >  > tesla cad
 >  > programs come up with errors when you exceed 15-16 turns (i.e. Tesla
Coil
 >  > Cad V2.0).  Is there a reason for this?  I know it will effect
coupling,
 >  > primary losses, etc..., but wanted
 >  > to hear what your experiences were with large number of turn primaries.
 >
 > I'm mystified by the repeated emphasis given to the number of turns
 > given that most TC operations are dependent on impedances. For
 > example, the voltage stepup ratio in a disruptive coil is a function
 > of primary and secondary impedances, gap losses are a function of
 > primary impedance and so on....
 >
 >