Re: Tesla Coil Grounding

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net> 

 >  >One technique that you could use when connecting the secondary ground
(i.e.
 >  >the RF ground) to the safety (i.e. green wire) ground is to connect it
via
 >  >a choke that has high impedance at 50 kHz (i.e. the TC operating
frequency)
 >  >but low impedance at 60 Hz.  The choke should be able to take the full
 >  >fault current of the HV side of the transformer.
 >  >
 >  >This way, if you get a primary to secondary short, via either dropping
 >  >something conductive on it (it happens!) or with a streamer connecting
in
 >  >an ugly way, you've got a low impedance ground for the 60 Hz. component.
 >  >The choke will keep the RF out of the building safety ground system.
 >  >
 >
 > Hi Jim, Coilers,
 >
 > That's sounds like a workable idea that I'll have to try when the cold
 > weather finally departs from Southern Ontario and I can resume coiling
 > once again.  A large gauge wire wound onto an old ferrite or powdered
 > iron toroidal core comes to mind, provided that the right properties
 > are chosen for the frequencies in question.


Now that I think about it, you don't even care if the core saturates (in
fact, this might be desirable) when a high current 60Hz fault occurs.  All
that would happen is that the impedance would be even lower, which is a good
thing.  So, some suitably sized wire on almost any old core would probably
work, because the RF current should be low, and the flux in the core
likewise.