Re: NST protection filter

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "C. Sibley" <a37chevy@xxxxxxxxx>

Not sure I understand.  Not critical as long as the
cutoff is below the resonent frequency of the primary,
correct?

For the sake of discusstion, if the resonent frequency
of the primary circuit were 150KHz, then you would
want to set the cut off frequency of the filter
somewhere lower correct?  Buy rule of thumb, what
would you design to, an octave lower (75Khz) or a
decade (15KHz) lower or what???

Thanks,

Curt.





--- Tesla list <tesla@xxxxxxxxxx> wrote:

> Original poster: Terry Fritz
> <vardin@xxxxxxxxxxxxxxxxxxxxxxx>
>
> Hi,
>
> There is no great math behind the filter's cutoff
> frequency.  It is not critical at all.  The
> values are mostly from how much power one want's
> to "waist" in the resistors and what cap size
> will not greatly interfere with the primary circuit.
>
> Cheers,
>
>          Terry
>
>
> At 06:28 PM 1/3/2006, you wrote:
> >I've learned my lesson and am in the proscess of
> >adding a "Terry Filter" to my coil, along the lines
> of
> >the one at
> >
> >http://www.hot-streamer.com/temp/NSTFilt.jpg
> >
> >If I did the math correctly, it has a cut-off
> >frequency of approximately 290KHz.  I assume that
> the
> >frequency response is adjusted up or down based
> upon
> >the resonant frequencey of the coil?  Is there a
> >discusstion/web page somewhere along these lines?
> >Doing a web search find a lot of hits but none
> >specifically describing the filter and it's
> >application for different frequencies.
> >
> >Seeking advice...
> >
> >Thanks,
> >
> >Curt.
> >
> >
> >
> >
> >__________________________________________
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>
>