RE: VTTC provisional results

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

Original poster: "David Trimmell by way of Terry Fritz <twftesla-at-uswest-dot-net>" <davidt-at-pond-dot-net>


Hi Herwig,

I would say very good results! Even at 3+ KW 16 inches is quite good for
filtered DC. The separating sparks may be from increasing ripple in the
filter (I have seen that in my setup)? 

One thing you could try for a former is to find some PE sheeting (60 mill
is very common here) and make a tube, welding the seam with a heat gun. I
agree PVC is realy bad with the carbon tracking. 

Could you get some photos of this coil in action?

Regards,

David Trimmell 

On Fri, 16 Mar 2001, Tesla list wrote:

> Original poster: "Herwig Roscher by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <herwig.roscher-at-gmx.de>
> 
> 
> James wrote:
> 
> > The arc would smoke the primary and short it (large carbon
> > track).
> 
> James,
> 
> Sorry to read that you faced the same problem.
> 
> > I rewound the primary as a funnel. It will be a pain to do 65 turns. 
> - Before taking this trouble I would like to make an other approach: 
> I am planning on substituting the PVC insulated house wire by 
> magnet wire of the same copper cross section. This would half the 
> height of the coil and reduce the voltage difference between the 
> uppermost turn of the primary coil and the secondary coil (as the 
> voltage of the latter increases with height).
> 
> As I suspect that the sharp edge of the flush screw, I used to fix 
> the wire, contributed to the effect, I shall try to find a better 
> solution. How did you solve this problem?
> 
> As PP has got a smaller dielectric factor than PVC it should create 
> smaller rf surface currents which are the reason for these carbon 
> tracks and flashovers IMO. Unfortunately I could not find a 8" PP or 
> PE form (should have thin walls!) up to now.
> 
> Regards,
> 
> Herwig
> 
> 
> 
>