[TCML] Q

[Jared Dwarshuis]

As coupling decreases, frequency splitting decreases. The secondary will
have its highest Q when completely uncoupled.

Secondary Q for a quarter wave coil will be highest at the self resonant
frequency ( C/ 4 wire length)

Any top load will decrease the Q of the secondary as it allows energy to
escape from the secondary. Large top loads allow more energy to escape per
cycle.

Low Q for the system means that energy is disappearing from the system
through spark formation.

The problem with lightly coupled coils is that you need real big tank
capacitors  (it gets expensive).

Jared Dwarshuis
On Dec 3, 2007 9:25 AM, Lau, Gary <Gary.Lau at hp.com> wrote:

> Comments interspersed:
>
> > -----Original Message-----
> > From: tesla-bounces at pupman.com [mailto:tesla-bounces at pupman.com] On
> > Behalf Of Jared Dwarshuis
> > Sent: Monday, December 03, 2007 5:28 AM
> > To: Tesla Coil Mailing List
> > Subject: Re: [TCML] Q
> >
> > You get higher Q in both the secondary and primary by diminishing
> coupling.
> > When coupling is small there is less frequency splitting and Q rises.
>
> Please share the basis suggesting that Q is a function of coupling?  I've
> not heard that before.  Of course higher coupling means that energy will be
> drained from one side faster than if coupling were low, but this has no
> bearing on Q.  Q deals with losses; energy transfer via coupling is lossless
> beyond the fixed losses in the L/C components and gap.  Truthfully, I'm not
> even sure that the concept of Q is relevant to complex non-linear networks
> (though I may be wrong).  I'm more accustomed to Q pertaining to a single
> component.
>
> > You can also get higher Q by operating the secondary at its
> characteristic
> > resonant frequency ( the wire length frequency)
>
> Again, this is news to me.  Please share what evidence might suggest this?
>  The Q of any particular component is unaffected by other components.  I
> think the Q of a secondary is what it is, regardless of toploads.
>
>
> > Smaller top end capacitance will also increase the Q of the secondary,
> but
> > unfortunately will give a poor impedance match with less power output.
> >
> > One wants the Q of the entire system to be low. This means that your
> energy
> > is being dissipated as sparks.
>
> I agree that sparks cause the secondary Q to plummet, but I don't think we
> *WANT* the Q to be low?
>
> Gary Lau
> MA, USA
>
> > Jared Dwarshuis
> > On Dec 2, 2007 8:52 PM, nnanred1 at netzero.net <nnanred1 at netzero.net>
> wrote:
> >
> > > hi,
> > > yes it does effect the number of cycles.  if ur loseing a lot of
> energy
> > > each cycle the circuit will quickly wind down.  in the limit the
> circuit is
> > > "dead beat."
> > >  by now,
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