Re: variac size and flashover

5A is probably enough variac for that NST. Of course, if you get a great
deal go big. ;) You may want to move up on the power levels later.

Sounds like your coil will be a lot like mine. I'm using 15KV 60mA and a
6" secondary. An 8" inner turn on the primary was too small. I'm at
about 10" on the inner turn now, and all is well. I blew my homemade
caps on the first run with the new primary though, and didn't make it to
full power. So there may still be problems. Waiting on my MMC order so I
can get the coil back up and running. 

If it sparks from the secondary ground wire to the primary, it's too
close. Otherwise I think you're OK. The exact distance you need will
depend on the rest of your coil setup. 


Tesla List wrote:
> Original Poster: pmathus-at-learningco-dot-com
>      2 questions for the gurus:
>      1)  How big a variac do i need? 5 amps?  15 amps? I'm going to be
>      running a 12kv 60ma NST.
>      2) What's the recommended distance between the first turn of the
>      primary and the secondary to prevent flashover?  I was thinking 2",
>      (for a 6" secondary) but now i'm wondering if that's too much. . .
>      thanks,
>      paul mathus