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RE: [TCML] More wire better?



Hmmm - It's challenging to piece together the nature of your coil based only on sparsely provided clues.  So you're using 5.5 miles of 23 gauge wire on a secondary.  That's over 44 pounds of wire.  Wound on a 40 inch diameter form 68 inches long would give you a 3.7 HENRY secondary.  And if you top that with a 36"x50" toroid, the Fo is all of 7.1 KHz.  That's got to be hard on the ears.  I guess that you would need a large tank capacitor!

How does using a large tank capacitor minimize required ballast?  I've seen voltage doublers used on MOT-based power supplies, where in addition to functioning as voltage doubler components, the caps act as capacitive current limiters.  But those caps operate strictly at the mains frequency and are separate from the tank capacitor.

Regards, Gary Lau
MA, USA

> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> Behalf Of Jared Dwarshuis
> Sent: Tuesday, December 18, 2007 5:40 PM
> To: Tesla Coil Mailing List
> Subject: Re: [TCML] More wire better?
>
> Hi Gary:
>
> We use large tank capacitance in part for high Q. We also use large tank
> capacitance as part of current limiting. A way to minimize pig ballast.
>
>
> On Dec 18, 2007 9:46 AM, Lau, Gary <Gary.Lau@xxxxxx> wrote:
>
> > If you are attempting to raise Q by increasing the numerator of
> > circulating-power / loss-per-cycle, wouldn't increasing the tank capacitor
> > value accomplish this as well?  The question then becomes do inductor losses
> > increase more slowly with inductance, vs. capacitor losses with capacitance.
> >  And to further complicate things, I think one must also consider what
> > happens to the losses in the other tank component - if you maximize Q in the
> > inductor, what have you done to the Q of the capacitor by forcing it to some
> > extreme value?  Correct me if I'm mistaken, but I'm assuming that it's the
> > combined Q of the tank circuit that matters.  I don't myself know the answer
> > and was wondering if you had evidence of one or the other.
> >
> > The answer however is academic, as there are many more variables and
> > constraints involved.  The primary capacitance must be selected to match the
> > charging capability of the power supply, and this takes precedence over Q.
> >
> > Regards, Gary Lau
> > MA, USA
> >
> > > -----Original Message-----
> > > From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On
> > > Behalf Of Jared Dwarshuis
> > > Sent: Monday, December 17, 2007 6:46 AM
> > > To: Tesla Coil Mailing List
> > > Subject: Re: [TCML] More wire better?
> > >
> > > Here is what we can say:
> > >
> > > Q = circulating power / loss per cycle
> > >
> > > We can do very little to influence the loss per cycle in the
> > denominator.
> > >
> > > We can do a lot to the numerator!
> > >
> > > Raise the circulating power to very large levels using gigantic
> > inductors
> > > and the system Q goes up.
> > >
> > > True there will be added resistive loss, but this is insignificant.
> > >
> > >
> > > Jared Dwarshuis, Larry Morris
> >
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> >
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