Re: Double Throw Spark Gap (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Wed, 10 Oct 2007 21:41:54 -0500
From: Crispy <crispy@xxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Double Throw Spark Gap (fwd)

I'm planning on using a 16.7nF tank capacitor made from 2x strings of 18
CDE 942's.  I'll probably be running the ARSG at maximum break rates.
The angle grinder is 11000rpm, meaning, with my design, 733 charging
cycles per second.  The storage cap seems to be fairly robust.  To test
it, I connected a spark gap in parallel with it in the DC supply
circuit.  Even with the gap wide enough so that it only fired every 10
seconds or so, it survived a significant number of repetitions with no
apparent damage.

On Wed, 2007-10-10 at 19:37 -0600, Tesla list wrote:
> ---------- Forwarded message ----------
> Date: Wed, 10 Oct 2007 10:03:14 -0500
> From: Bert Hickman <bert.hickman@xxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Subject: Re: Double Throw Spark Gap (fwd)
> 
> What size tank cap are you planning to use and what is your planned 
> maximum break rate?
> 
> It will be interesting to see if the series chain of electrolytic 
> capacitors (used in the storage cap) can survive repetitively sourcing 
> high current charging pulses at moderate break rates...
> 
> Bert
> 
> Tesla list wrote:
> > ---------- Forwarded message ----------
> > Date: Tue, 09 Oct 2007 10:04:15 -0500
> > From: Crispy <crispy@xxxxxxxxxxx>
> > To: Tesla list <tesla@xxxxxxxxxx>
> > Subject: Re: Double Throw Spark Gap (fwd)
> > 
> > I have done the relevant calculations as they pertain to DC coils.
> > Using a reasonably sized charging inductor (around 25mH or so), there is
> > a significant margin for the dwell time, and it would not be a problem.
> > Another way to think about it is that normal resonant charging DC coils
> > usually use an inductor with a value in the Henries, which still leaves
> > reasonable charging time.
> > 
> > Using this type of gap in an AC coil, the characteristics of the power
> > supply would determine if it could charge enough in that time period.  I
> > imagine that a pig, not being current limited, would be sufficient.
> > Unfortunately, I can only speculate here, because I have neither the
> > money to buy a pig nor power capacity to feed it.
> > 
> > Chris B
> > 
> > On Tue, 2007-10-09 at 06:48 -0600, Tesla list wrote:
> >> ---------- Forwarded message ----------
> >> Date: Tue, 9 Oct 2007 03:46:42 -0700 (PDT)
> >> From: Yurtle Turtle <yurtle_t@xxxxxxxxx>
> >> To: tesla@xxxxxxxxxx
> >> Subject: Double Throw Spark Gap
> >>
> >> I haven't really been following this thread, so
> >> forgive me if this comment has already been addressed.
> >>
> >>
> >> Regarding the following circuit:
> >>
> >> http://tangent.cluenet.org/~chules/hv/tesla/dtsg.html
> >>
> >> Does everyone think the cap can charge adequately in
> >> the same amount of time it can discharge? Without
> >> doing the math, I gotta believe that if one set of
> >> flying electrodes zooms around at several hundred rpm,
> >> the presentation time for the charging portion will be
> >> too short to fully charge the cap. After all, most rsg
> >> coils are charging the whole time they aren't
> >> presenting (well not exactly). I guess you gotta know
> >> the dwell time and the size of the pig feeding this.
> >>
> >> Adam
> 
> 
>