RE: Grounding before secondary

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Lau, Gary" <gary.lau@xxxxxx>


Most NST-powered coils absolutely must not ground either side of the
spark gap or tank cap or primary coil.  This is true whenever you have
an NST with a mid-point grounded secondary coil - which is the case for
typically anything over 6kV.  For mid-point grounded secondary NST's,
the case of the NST is typically connected to RF ground, as opposed to
your mains (3rd wire) ground.  The schematic for my 15kV NST coil is at
http://users.rcn.com/laushaus/tesla/myschematic.gif

If your NST has one side of the secondary tied to the core (case), then
since that secondary side is grounded, you may ground that spark gap
connection and primary coil connection:
http://users.rcn.com/laushaus/tesla/minicoil_files/minicoil.gif

Regards, Gary Lau
MA, USA

> Original poster: John Krinks <jk175400@xxxxxxxx>
>
> I'm a bit confused as where to ground the coil. I have no problem
grounding
> the secondary, that's easy. The trouble comes in grounding the input /
spark
> gap / capacitor / primary coil section. I was looking through some of
my old
> electrical engineering books, but couldn't quite find a schematic that
matched
> that with a ground. Would it be okay to run a ground off of one of the
spark
> gap electrodes (a few inches away from the actual gap)? Should it be
after the
> spark gap? After the capacitor? Your input is greatly appreciated, I
owe much
> of my progress to you guys. It's been a little over a month, but I'm
almost
> done with my first coil - just got to pick up a few 12 packs of
bottled beer
> to make that capacitor.
>
> John Krinks
>