Re: Top-load altering Q-factor of secondary cct

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>

On 24 Oct 2005, at 10:36, Tesla list wrote:

> Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>
>
> Hi Gavin,
>
> I believe the formula you state here is meant to be interpreted as:
>
> Q = 1/R * sqrt(L/C)  where the sqrt is in the numerator.
>
> As the top load is increased, the Q will decrease (everything else the
> same).  However, as the topload is increased, the frequency will
> decrease and the copper losses due to skin effect and proximity effect
> will be reduced.  If R decreases faster than 1/sqrt C decreases, then
> the Q could be affected positively.  I just dont know who wins.

I should add a note to my previous post on this subject - not all
secondaries will experience a rise in Q as you go from no topload to
some topload. Some as Gerry notes drop and continue to drop with the
addition of any amount of topload.

Malcolm

 A lot
> depends on the degree that proximity is saturated and how the skin
> depth compares to your wire quage.  I've been working on a program to
> compute Q (including proximity and skin effects) that uses the Fraga
> equation.  This should be available tonite at:
>
> http://hot-streamer.com/temp/GerryReynolds
>
> There is (or will be) the executable (for windows), and the source and
> Makefile (if someone wants to recompile it for their platform).  I had
> a bug that affects awg24 so if the version that you get doesn't work
> with 24, the fix is on its way.
>
> Gerry R.
>
> >Original poster: Gav D <gdingley@xxxxxxxxx>
> >
> >Hi all,
> >I read in a book written by Richard Hull that increasing the
> >top-load will increase Q-factor of a TC secondary. I assume there is
> >a limit to this set by Q= 1/R sqrt(L/C). Has anyone either
> >experienced this and/or know of any theory for why this happens?
> >
> >Thanks,
> >
> >Gavin
> >
> >
>
>
>
>
>