Re: MMC vs Maxwell comparison

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

Original poster: "Malcolm Watts by way of Terry Fritz <twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

Hi John,
         Thanks for the info. I worked a few figures based on what I 
know about the coil and came up with the following:

On 21 Feb 2002, at 11:39, Tesla list wrote:

> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<FutureT-at-aol-dot-com>
> 
> 
> >
> > John;
> >
> > When you consider the fairly thin wire leads that connect the individual
> > capacitors together in series with respect to the amount of current that we
> > ask of them to deliver at the moment the gap fires, I've often wondered if
> > this arrangement doesn't limit the MMC's performance compared to a single
> > capacitor unit such as your Maxwell.
> 
> 
> 
> Daniel, Malcolm, all,
> 
> The thin wires may limit the current to some degree, although
> they don't get warm.  The warming of the caps showed that they
> have some trouble dealing with the current involved.  I didn't notice 
> any difference in the sound of the sync gap.  I don't have
> any easy way to measure the current in the tank.  Maybe 
> someone else will do such a test.  Overall, I'm very satisfied
> with the MMC's though.  Certainly, if I used more strings, this
> would help, but the way I did the test seemed representative
> of how folks use their MMC's.  Malcolm, the Lpri is only 24uH
> which is less than I usually use, but representative of what
> many coilers use I suppose.  

Based on Cp = 12.4nF, Lp = 24uH I get the following Ip (pk) under the 
conditions: Vpk = 15kV, Ipk = 340A
            Vpk = 21kV, Ipk = 477A

In the first case I would be using 7 - 8 strings in parallel and in 
the second, 11 - 12 strings.
    I work on peak current rather than RMS current since it's peak 
current delivery that's of interest to me. I think if you spent the 
extra, the performance would increase and the heating would diminish 
to match. Certainly I've found the caps to be excellent if the rule 
I've outlined is followed with breakrates around 200 or so.

Regards,
Malcolm