Re: electric strength for "x" cm of "y" material

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Ward <steve.ward@xxxxxxxxx>

Hi Dmitry



so - the problem was not in the insulation breakdown - even at such
small thickness? then it`s cool - i`m not going to face your problem :-)



Nope, never punctured the plastic, but perhaps because i kept the 
runs pretty short =\.  I think you will find that you will have to 
actually build your coil before you know how well your insulation 
will work... its just hard to say unless of course you were to 
submerge it in oil.  Then we know there is no air between primary and 
secondary conductors.


maybe you should try internal primary too? then you could use end caps
on secondary coil form - maybe they`ll help?



This could work, but unfortunately my secondary form was cardboard, 
so it would need an inside layer of plastic and then maybe some end 
caps.  Perhaps i could use a 5 gallon bucket and build it inside of that...


> it sure is
> difficult to keep the corona from forming, especially when the added
> dielectric makes the E-field greater outside of the dielectric!

outside of the dielectric? how it possible? there`s an air and the
conductors outside - why does the field increase outside?



Well, say there is (just throwing out random numbers) 50kV between 2 
conductors and they are seperated by 10cm.  The electric field (with 
just air) would then be 500kV/m.  But say we introduce a 5cm thick 
sheet of some poly material where its dielectric constant = 2.  That 
would make the electric field in the air become twice that of inside 
the plastic, right?  But we must still arrive at our 500kv/m 
figure.  So there should be 16.6kV "dropped" across the plastic, and 
33kV "dropped" across the air... except now we only have 5cm of air, 
so now the E-field in the surrounding air would be 666kV/m.  I 
believe this can cause problems in some cases with corona 
forming.  Please correct me if my theory/understanding is incorrect here.


> Good luck with your internal primary, hopefully it will not be a
> source of headaches for you in the future!

thanx, and i wish you luck too - with magnifiers, although i think
it`s possible to achieve similar results with a conventional coil.



I agree completely :-) and that is why the magnifier sits dormant.

Steve