Re: A SSTC Ground ?

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

Original poster: "Chris Arnold" <chris_arnold-at-msn-dot-com> 

Finn,

I've found that often SSTCs are somewhat less picky about where they're 
grounded, just so long as they have a *reasonable* (i.e. less than 20 foot 
long) ground path.  I don't think your problem is so much an issue of poor 
grounding as it is the amazing E-field induced effects in the environment 
around you.  I personally don't like to have any of my electronic equipment 
near my CW coils while they're in operation, simply because I've seen the 
power that can be delivered through say a finger accidentally touching a 
grounded object.  It's just that for a given average power level the sparks 
from a solid state coil are much shorter, which invites the operator to 
maintain less of a respectful distance.  I don't know of many people out 
there who trust their 'scopes and the like to be within a few feet of a 
multi-kilowatt coil.

So basically I don't think it's a grounding problem, it's just that your 
coil is working very well and causing any conductive object around it to 
gain a more than respectable voltage.

Chris Arnold

>From: "Tesla list" <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: A SSTC Ground ?
>Date: Mon, 15 Sep 2003 17:16:08 -0600
>
>Original poster: Finn Hammer <f-h-at-c.dk>
>
>SSTC gang.
>
>I`ve got my IFRP460A H-Bridge up and running.
>
>I am running DC in, and everything gets "electrical" when the coil is
>running.
>
>I find it hard to establish a ground reference, because even short
>lengths of wire pick up enough potential to arc trough insulation.
>
>My present grounding is only 2 meters away from the coil, and yet it
>arcs to the table, myself, coax from scope to Pearson Current Monitor
>etc. etc.
>I fear for my scope.
>
>What are you guys using as a ground?
>
>Cheers, Finn Hammer
>
>
>The coil is based on the schematics posted on Aron and Justins site.
>
>This means beefy driver ( tc4428/ IRFP9540/ IFRP530 )
>Source of oscillations is a TL494 triggering an AD8561 comparator.
>(Sometimes an antenna is doing the triggering)