Re: The right capacitor match?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi Ethersmith,

If you already have the 940C series and dont mind losing them then by 
all means try them.  The 942 series is the prefered caps these 
days.  Keep in mind that a 15KV NST is a RMS spec and the peak 
voltage is 1.414 times larger (21.2KV).  Also, if you plan on using a 
variac and giving the NST a 140V input, the peak voltage should be 
scaled up accordingly.  I design my MMC strings for 28KV using a 15KV 
NST but I run my SRSG at 24KV.

Gerry R.

> Original poster: "Ethersmith" <siveya@xxxxxxxxxxxxxx>
>
> Greetings,
>
> New coiler here, hoping to find some aid.
>
> I have a 15K/30mA NST which I am building an MMC for.
>
> Given LTR of 1.5* I have come up with a match in the range of .008mF
>
> I have had trouble finding HV caps in the lower Farad range. (Any current
> suggestions would be greatly appreciated).
>
> I have found some Cornel Dubilier (940C30S47K) "Snubber Capacitors" that
> look like they will work. They are not on Terry's known Bad Caps list. They
> are rated at 3kv .047mF
>
> If I have done my math properly, I only need six of these in series to get a
> capacitance of .00783mF (which is in my LTR range) and a voltage of 18,000v
> (which exceeds my NST voltage)
>
> This seems small and cheap compared to what others seem to need regularly.
> Is it just that my coil is one of the smaller ones out there? Or have I made
> some egregious error?
>
> Your input is golden.  Thank you.
>
> --Ethersmith