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Re: design questions
In a message dated 1/12/99 2:41:48 PM Pacific Standard Time, tesla-at-pupman-dot-com
writes:
>
> I am myself designing a tank supply with a 20 kVrms pig, but a 50 kVA one.
> Modeling it with MicroSim I reached the same numbers.
>
> Vpeak = 1.41 * 20000 = 28200 V
>
> Using DC (not AC!) resonant charging actually you MORE than double that
> figure because the resonant charging reactor gets already some startup
> current when the tank supply is short circuited by the RSG. Let's say:
>
> Vcpeak = 2.1 * Vpeak = 60 kV
>
> Now, if you also suppose that the primary capacitor has left some voltage
> Vr on it when the RSG opens (and this voltage is of opposite polarity to
> the charging voltage), the charging reactor will sink more current into the
> capacitor and will charge it to about:
>
> Vc'peak = 2.1 * Vpeak + 2 * Vr !!!!
>
> In reality we know that this Vr is very small so that should not represent
> a problem.
>
> Instead to oversize the capacitor to ? * 60 kV I tought to leave some
> margin (probably use a 100 kV capacitor) and use a safety gap on it "just
> in case..."
>
Just out of curousity, what is a 100 kv capacitor in the .05 ufd to .10 ufd
range likely to cost for this application? Sounds like serious money.
Ed Sonderman