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

Re: Sonderman Testing



---------- Forwarded message ----------
Date: Wed, 1 Oct 1997 07:44:30 +1200
From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
To: tesla-at-pupman-dot-com
Subject: Re: Sonderman Testing 

Hi Ed,

<snippage>
> Thanks for the response.  How wide of a gap do you think I can use on the
> capacitor safety gap and not risk killing it?  If you say maybe 1/2" and
> let's assume I find the current problem and fix it, would this safety gap
> across the cap never fire during normal running if the coil is in tune? 

1/2" with the type of safety gap electrodes you have would take you 
pretty close to the peak V rating for the cap IMO. Sounds like a good 
distance. I can't guarantee it would never fire because that 
*entirely* depends on whether your main gap fires often enough to 
keep the cap from charging to too high a voltage. A rotary miss would 
certainly cause it to fire. I mentioned this some time ago but 
planting a static gap across the rotary affords the same cap 
protection and dumps the cap into the primary as well. I'd be tempted 
to move it there so you can see how your rotary is behaving.

> At
> what distance would you expect it to fire during norman running?

I would hope it doesn't. 

> You said maybe the extra resistance of the old primary interconnect wiring
> was helping the gap to quench.  I also had a three gap static gap in series
> with the rotary in the old configuration.  This whole problem did start when
> I rewired the primary with copper instead of two pieces of RG213 in parallel.
>  I am stubborn and have been fighting this problem for many months now.  I
> would like to think I (we) could resolve it with the current design but I am
> about ready to rebuild the primary interconnect wiring and put it back like
> it used to be.

Well, you don't need a lot of series damping resistance at your power 
levels and the old wiring sounds as if it was behaving like a nice 
high power resistor of an ohm or two. I think the key is in your 
rotary behaviour. I'd stick a more robust gap across the rotary
to see how often it misses but use the power anyway. I have done this 
BTW and it works.
    I think Bert's post was an excellent one and described the 
problem well. Personally, I'd be tempted to build a much larger coil. 
My ten inch one will do far better even at low power levels than a 
smaller one. At some stage I might compose a post on the tradeoffs you 
seem to be running into.

Sorry it's such a nuisance.
Malcolm