Re: Gen 4 Larger coil <assistance please>

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

Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

Hi Finn,

Unlike standard NSTs, pole pig systems have a few more variables so the 
MMCcalc program may need some help getting a good answer as you have shown 
here.  The newer program Kurt Schraner made at:

http://hot-streamer-dot-com/temp/Old2002Files/2002-04/MMCcalc2xls.zip

May be a little better for more complex systems.  RMS current is directly 
proportional to break rate so that is a big factor as is 
ballasting.  MMCcalc is pretty basic and does not really "think" much.  As 
you show, it may be better to try and get enough strings for the current 
first and then add caps to get to the right voltage in systems that can 
vary charging current and break rate.  I have not thought about this much...

Cheers,

         Terry

At 08:13 PM 1/14/2003 +0100, you wrote:
>All!
>
>I was thinking that it still seems like an awfull lot of caps for the
>job, so here are some more thoughts.
>-------------------------------------------------------------------------
>MMC Calculator  Ver. 2.2   9/12/2000  Terry Fritz
>Transformer voltage =  14400
>Transformer current =  1
>Firing voltage =  20364.62
>Fo =  50000
>Break rate =  1000
>Thermal dissipation constant =  22
>Individual cap value =  1.5E-07
>
>Strings  Caps/Str  Capacitance  Voltage   Temp C    Cost              I
>Arms
>   4        9         66.67        18000    40.55   36.00  :-|   :-((
>55.29
>   5       11         68.18        22000    27.14   55.00  :-))  :-((
>56.54
>   6       13         69.23        26000    19.43   78.00  :-))  :-(
>57.41
>   7       15         70.00        30000    14.60  105.00  :-))  :-|
>58.05
>   8       17         70.59        34000    11.36  136.00  :-))  :-|
>58.54
>   8       18         66.67        36000    10.14  144.00  :-))  :-|
>55.29
>   9       19         71.05        38000     9.10  171.00  :-))  :-)
>58.92
>--------------------------------------------------------------------
>   9       20         67.50        40000     8.21  180.00  :-))  :-)
>55.98
>------------------------------------------------------------------------------
>
>As can be seen, the cap has to have much too many caps in series in
>order to also have enough strings to handle the rms current. 40kV is way
>overshoot.
>
>But the geekcaps are good for a bit more than 8 amps, so perhaps it
>would be allright to go for the 58/8 ~7 string version, which goes like
>this:
>
>  7       15         70.00        30000    14.60  105.00  :-))  :-|
>58.05
>
>105 caps.
>
>Another route would be to lower the breakrate to 500, and double the
>capacitor, this would also reduce the need for primary turns to a more
>pretty 11 turns:
>
>--------------------------------------------------------------------------------------
>MMC Calculator  Ver. 2.2   9/12/2000  Terry Fritz
>Transformer voltage =  14400
>Transformer current =  1
>Firing voltage =  20364.62
>Fo =  50000
>Break rate =  500
>Thermal dissipation constant =  22
>Individual cap value =  1.5E-07
>
>Strings  Caps/Str  Capacitance  Voltage   Temp C    Cost              I
>Arms
>   8        9        133.33        18000    20.27   72.00  :-|   :-((
>78.19
>   9       10        135.00        20000    16.42   90.00  :-|   :-(
>79.17
>  10       11        136.36        22000    13.57  110.00  :-))  :-|
>79.97
>  11       12        137.50        24000    11.40  132.00  :-))  :-|
>80.63
>  12       13        138.46        26000     9.72  156.00  :-))  :-)
>81.2
>--------------------------------------------------------------------
>  13       14        139.29        28000     8.38  182.00  :-))  :-)
>81.68
>
>choosing the 9/10 solution would bring this picture:
>
>9       10        135.00        20000    16.42   90.00  :-|   :-(
>79.17
>
>Hey, this is getting close to an EMMC, good! And at 90 caps, approaching
>the maneageable.
>
>Cheers, Finn Hammer
>
>
>Tesla list skriver:
> >
> > Original poster: "Finn Hammer by way of Terry Fritz 
> <teslalist-at-qwest-dot-net>" <f-h-at-c.dk>
> >
> > Glenn,
> >
> > With a topload 12" by 50 inches, you are around the 50kHz mark allright.
> >
> > With a 14.4 kV polepig, you can fire the caps at 20 kV, so for a power
> > troughput of 14 kW and a breakrate of 1000 BPS, you should dispence 14
> > joule at a time, which is possible if your capacitor is 70 nF.
> >
> > Using MMC calc, set up for the Geek group caps, with a heating coeff. of
> > 22, I get 9 strings of 19 caps, for a total of 171 caps.
> >
> > You should then tune the coil at 16 turns.
> >
> > Cheers, Finn Hammer
> >