Re: apartment grounding (was: I'm a newbie coiler!- apartment coiling)

["Tesla list" <tesla@xxxxxxxxxx>]

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

Hi Jim,

I agree, the counterpoise should be grounded.  If its not, the 
voltage on the secondary where the primary is located could settle on 
some unspecified level (depending on how capacitances are 
distributed) and flash over to the primary.  I'm also thinking that 
even with a counterpoise,  any capacitance to other objects in the 
room that are earth gounded will return to the secondary base by way 
of green wire (if this is the only return path).  This capacitance 
may be very small and its impedance may be very large (at some 
appropriate frequency) so the RF choke impedance may or may not be 
significant to reduce this RF return current.  Any power arc to an 
earth grounded object in the room would most likely result in the 
power arc current returning via green wire with or without the choke 
(the choke would probably just flash over).  It is very important to 
NOT allow streamers in the apartment setting from hitting anything 
other than the counterpoise, or something directly grounded to it or 
the secondary coil base.

Gerry R.

> Original poster: Jim Lux <jimlux@xxxxxxxxxxxxx>
>
> At 08:54 AM 3/14/2006, you wrote:
> > Original poster: "Peter Terren" <pterren@xxxxxxxxxxxx>
> >
> > For a ground, connect your secondary base to a large aluminium 
> > sheet or a square sheet of fencing wire at least as wide as the 
> > coil is high. A Faraday cage is better though and can be very 
> > simple with much less RF.  A Faraday cage can be connected to mains 
> > earth if desired but not essential.
>
> I'd make sure there's some sort of path to "earth ground".. it can 
> be pretty high impedance, but if it's totally floating, and it's a 
> dry day, you can build up a remarkable charge on something that big, 
> and it's unpleasant to get the static spark.  OTOH, if it's sitting 
> on a concrete floor or unpainted wood, or 20 year old apartment 
> carpeting with accumulated grime and beer providing a conductive 
> path, then you're in great shape.
>
> Think about one of those antistatic wrist strap things with the high 
> resistance wire.
>
>
> > This is one I made for the local Uni Physics Dept with a cage.
> > http://tesladownunder.com/Tesla%20display.htm#Tesla%20coil%20(Physics%20Dept)%202006
> >
> > Peter
> > Tesladownunder