Re: MOT resonant cap size

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

Original poster: "tesla by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla-at-paradise-dot-net.nz>

Hi Henry et al

I might be corrected on this point but a method I have used.
Assumes NO inductive ballasting on the primary side of the MOTs

I measured the HV side inductance(with mains side shorted) with a meter. I
get around 6Hy per MOT. As no flux in common Ltot is simply sum of MOT
inductances. This figure can be plugged into F=1/(2pi(LC)^0.5) where C in
tank cap value and solve for F

An interesting check I did on a system a few yrs ago was to use a function
generator directly into the Tesla primary, short the SG and use a multimeter
across the capacitor to actually measure what freq Vc peaked at. If
available I'd suggest using an audio amp to drive the Tesla to ensure Low Z
and reasonable power.  My measurments produced results lower in freq (30Hz I
recall) than I had expected given tank Cp and NST Isc. This was on NST based
system BTW
I've never seen this method mentioned on the list and would be very
interested to hear comments which might explain lower measured freq or
whether this method might be invalid for other reasons.
And finally I suspect I'm near resonance with 6MOT's and 88nF given the arcs
across the protection gap. (at least10mm)

Best
Ted Linney in NZ

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Saturday, October 12, 2002 1:04 PM
Subject: MOT resonant cap size


> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<Hhchicken1-at-aol-dot-com>
>
> Hi everyone,
> How would I go about working out the size of a resonant tank cap for my
> 6-pack MOT supply? (13kV, 200-400mA)
> I'm not actually trying to use a resonant cap, rather avoid it!
>
> Thanks,
> Henry
>
>
>
>