Re: [TCML] Faraday Cage

[<pterren@xxxxxxxxxxxx>]

You should never require any currents to come back via the mains earth .
Even on my briefcase TC, it jumped onto the mains power lines at my switch, 
blowing the switch and tripping the RCD.
That took out 1/4 of the power to a science exhibition with no access to the 
power board. I raced around with extension cords and did a reasonable 
restoration job.
No-one knew it was me of course...
I now run an isolation transformer and a counterpoise even for the small 
one.

Make your RF earth from the secondary base join your counterpoise and strike 
points and attachment for chicken sticks, fluoro tubes etc.
You may have to connect to mains earth for safety but don't allow a strike 
that has to come back via the mains.

Peter

-----Original Message----- 
From: Jim
Sent: Wednesday, June 19, 2013 9:32 PM
To: tesla@xxxxxxxxxx
Subject: Re: [TCML] Faraday Cage

Great explanation. My main objective is to protect sensitive electronics
at a fair. Electronics such as pacemakers, hearing aid devices, smart
phones, computers etc..
In reason #3 you wrote that I do not want stray high voltages on mains
earths. Are you saying that I do not want the arc to go directly to earth?

Pardon my ignorance and thanks for the assistance.

Jim

On 6/17/2013 9:06 AM, pterren@xxxxxxxxxxxx wrote:
> The bottom is the metal plate. There is no top plate. The cage is
> grounded to NST and mains earths but there should not be much current
> flow in these.
> It is probably best to regard this not as a Faraday cage but as
> 1 A spark shield for (some) personal and viewer safety.
> 2 A safety gap. by allowing a spark from the toroid the voltage on the
> toroid doesn't get to build up as much and interference is less.
> I've seen it happen with news cameras on a small coil. Stop the spark
> and they get hash on their $100k cameras.
> 3 As an earth.  This is probably the most important as you do not want
> stray high voltages on mains earths.
> 4 To prevent voltages developing on nearby conductors such as people
> or equipment (by capacitance with the toroid).
> None of these really need the top plate.
>
> I really have no idea about EMI other than my wife doesn't like it.
> (Interferes with the TV when I use the big coil outdoors)
>
> Peter
>
> -----Original Message----- From: Jim
> Sent: Monday, June 17, 2013 6:48 PM
> To: Tesla Coil Mailing List
> Subject: Re: [TCML] Faraday Cage
>
> Hi Peter,
>
> That's a nice looking cage. I noticed that it did not have either a top
> nor a bottom. Are you using the cage for EMI shielding? Also, do you
> have the cage grounded at the same point as the coil?
>
> Thanks,
>
> Jim
>
>
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla


--






_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla 

_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla