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Re: caps an the resonant freq.
Kerry,
Follow Ed's advice, but instead of building up the poly in multiple layers,
make two or three single-thickness caps and wire them in series. This will
make for a much more robust cap, and the extra aluminum foil is dirt
cheap.
The reason why such multiple series caps work out better is that each
cap section only sees a fraction of the total voltage, and thus
localized corona effects are GREATLY reduced. Corona is the great
killer of caps. Most people who have used this technique would never
go back to the old multi-layer cap designs. Try it.
Fr. Tom McGahee
> <<
> well I am reading the articals in the arcives about caps, and I read some
> people are using .06" poly, or it reads 6 mill poly, my question is, is it
> hundreths of an inch or thousands that i should look for I got 2 sheets of
> hdpe of .03" thickness and I just want to make sure that I am not
wasting my
> time building the caps with the wrong thickness of plastic
SNIP
>
> kerry
> >>
> Kerry,
>
> Two sheets of .030" thick ldpe or hdpe is what you want - depending on the
> desired operating voltage of course. In my opinion, two sheets of .030" is
> good for about 9 kv ac maximum. Three sheets are good for 12 kv operation.
> You first calculate the resonant frequency of the secondary using its
> inductance, self capacitance and the added capacitance of the top load
> (toroid). Now you calculate the resonant frequency of a primary coil and
cap
> to match the secondary frequency.
>
> Ed Sonderman
>