[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [TCML] Faraday Cage Safety



The hole guideline is for rf propagation via e field, not generally what you would be doing. 
the h-field (magnetic) isn't stopped by a mesh

The cage around a coil is more about stopping sparks.

On Aug 4, 2013, at 16:59, mddeming@xxxxxxx wrote:

> Hi Amir,
> 
> 
> The condition for a good Faraday cage is Mesh size << shortest wavelength generated, For a TC, this means that from a purely electrical standpoint, you could use almost anything from chicken wire to chain link fence. HOWEVER, if this is going to be somewhere that the public might get authorized (or unauthorized) access, then the mesh should be finer than the diameter of the smallest fingers that can possibly sneak within 50 feet of it; because they will.
> 
> 
> Matt D
> 
> 
> 
> -----Original Message-----
> From: Amir Mojarradi <ln2guy42@xxxxxxx>
> To: tesla <tesla@xxxxxxxxxx>
> Sent: Sun, Aug 4, 2013 4:43 pm
> Subject: Re: [TCML] Faraday Cage Safety
> 
> 
> Hi Ed,
> 
> Thank you for sharing your insight on Faraday cage safety. I will follow your 
> advice and create a Faraday cage that covers the entirety of the coil. Do you 
> have any advice as to how fine the wire mesh should be? 
> 
> 
> Thank you for your kindness, 
> 
> 
> Amir 
> 
> 
> 
> -----Original Message-----
> From: Ed Phillips <evp@xxxxxxxxxxx>
> To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
> Sent: Sat, Aug 3, 2013 12:49 pm
> Subject: Re: [TCML] Faraday Cage Safety
> 
> 
> I'm not sure about the aesthetics of the cage but can add that for sure 
> the spark gap, capacitor, and all leads to and from the primary need to 
> be shielded as well, probably better than the top of the coil itself 
> because, in addition to the desired primary frequency, there will be VHF 
> signals of enormous peak power which will probably get into everything 
> in the vicinity and are potentially damaging.   You haven't indicated 
> the size of your upper terminal but you should certainly expect your 
> streamers to reach  the sides rather than the top.  I have a coil of 
> similar dimensions operating from a 9 kV NST and it easily throws 27" 
> streamers and should probably do better with a good spark gap.  You 
> should also have an 'RFI' filter in the primary circuit. 
> 
> More experienced opinions will surely follow.
> 
> Ed
> 
> 
> 
> _______________________________________________
> Tesla mailing list
> Tesla@xxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla
_______________________________________________
Tesla mailing list
Tesla@xxxxxxxxxx
http://www.pupman.com/mailman/listinfo/tesla