Re: PLL-controlled SSTC?

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

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

Would it not be possible to use a some means (eg. a current transformer or
feedback winding) to detect the change in the resonant frequency, then feed
the signal into the input terminal of the PLL so that the PLL's internal VCO
could track the secondary frequency?

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, July 06, 2002 2:19 AM
Subject: Re: PLL-controlled SSTC?


> Original poster: "Daniel McCauley by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>
>
> After some thinking. . .
>
> Actually a PLL circuit really wouldn't work in this case.  The problem is
> that when a arc streamer propogates it actually changes the resonant
> frequency of the secondary and this ultimately kills the propogation of
the
> streamer.  The output frequency of the oscillator doesn't really change
much
> during such a propogation.
> A PLL on the output oscillator really wouldn't do anything since the
> frequency is relatively constant.
>
> What would be needed is some kind of feedback to detect when the output
> current begins to drop or something similar.
> Richie Burnett uses a simple technique to simply feed back some of the
> output voltage back into the feedback of the TL494 chip (See his website).
> Its not very elaborate, but pretty effective for what its worth.
>
> Dan
>
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