Re: [TCML] Secondary self frequency

[bartb <bartb@xxxxxxxxxxxxxxxx>]

Has it been verified that the toroid was connected during measurement? I 
remember Andrew specifically mentioning selfC (which I personally always 
refer to as the sec without other components).

But with everything installed, yes, likely 320kHz or in the neighborhood.

Regards,
Bart Anderson
Modesto, CA USA

Quarkster wrote:
> Ed -
>
> Andrew's secondary dimensions are 4" OD, with a winding length of 22".
>
> With his 4.5" X 18" diameter toroid installed, he is measuring a 
> resonant frequency of around 515KHz.
>
> This seems far too high a frequency for a coil of these dimensions 
> WITH the topload installed; something appears to be wrong.
>
> Regards,
> Herr Zapp
> ----- Original Message ----- From: "Ed Phillips" <evp@xxxxxxxxxxx>
> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> Sent: Saturday, July 04, 2009 9:28 AM
> Subject: Re: [TCML] Secondary self frequency
>
>
> >    Late message because I've been out of town.  I use a home grown 
> > program to calculate SRF and here's what I get, based on a winding 
> > factor [turns / turns with no spaces] of 0.98:
> >
> > Diameter = 4.5 "
> > Winding length = 18" [You didn't say whether the 18" was winding 
> > length or total form length]
> > SRF = 555 kHz
> > Self capacitance = 7.6 uufd
> > Top load capacitance = 19.4 uufd
> > Loaded resonant frequency = 295 kHz
> > Turns = 653
> > DC resistance = 12.4  ohms
> >
> > Not too far from what you got so your results don't sound strange to me.
> >
> > Ed
> >
> >
> >
> > Andrew Robinson wrote:
> >
> > > Does this sound strange to anyone. A 4" OD x 22" (windings) 
> > > secondary using 22 gauge wire with a 4.5" x 18" spun alum toroid 
> > > having a self res freq of around 515kHz? I ran the tests in the lab 
> > > today and thats what im getting. For some reason though, I had 
> > > reason to believe it was going to be much lower. I'm gonna resubmit 
> > > this email next Thursday when I get a chance to get back in the lab 
> > > and im gonna take a video of myself taking the measurements. Maybe 
> > > im just doing something wrong.
> >
> > > ------------------------
> > >
> > > Regards,
> > > Andrew Robinson
> >
> >
> >
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>
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