Re: Capacitor help

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

Original poster: Bart Anderson <classi6-at-classictesla-dot-com> 

Thanks to all who replied:

It looks like opinions are shifting that LTR "may" give longer spark 
lengths as a side benefit from the main reason to run LTR with NST's 
(reducing NST and Cap stress).

For those interested, I ran some numbers for 9/30, 12/60, and 15/120 for 
resonant and LTR cap sizes. The data was pulled from Javatc. Surprise to 
me, it supports that LTR may give a couple extra inches at low 120 bps. . 
The program isn't looking at resonant rise or inductive kick, but 
considering the cap is nearly fully charged at resonant, it's a good 
indication of one vs. other. For what it's worth:

This table is 120 BPS (slight increase in spark length with LTR):

                        9/30        9/30        12/60        12/60
    15/120        15/120
                        Resonant    LTR         Resonant     LTR
      Resonant      LTR
                        9nF         23nF        13nF         35nF
     21nF          55nF

-------------------------------------------------------------------------
BPS:                    120         120         120          120
      120           120
Firing Rate (ms):       8.33        8.33        8.33         8.33
     8.33          8.33
Charge Time (ms):       13.5        34.5        13           35
       13.125        34.375
Time Constant:          3.09        1.21        3.21         1.19
     3.17          1.21
Percent Charged:        95.43%      70.11%      95.94%       69.59%
   95.82%        70.24%
Cap Voltage:            12150       8923        16280        11808
    20323         14899
Cap Energy (j):         0.66        0.92        1.72         2.44
     4.34          6.1
Energy * Time (j*s):    80          110         207          293
      520           732
Spark length (inches):  26.5        28.2        43           46.1
     68.1          72.8

----------------------------------------------------------------------------

This table is 240 BPS (slight decrease in spark length with LTR):

                        9/30        9/30        12/60        12/60
    15/120        15/120
                        Resonant    LTR         Resonant     LTR
   Resonant      LTR
                        9nF         23nF        13nF         35nF
   21nF          55nF

----------------------------------------------------------------------------
BPS:                    240         240         240          240
  240           240
Firing Rate (ms):       4.17        4.17        4.17         4.17
  4.17          4.17
Charge Time (ms):       13.5        34.5        13           35
       13.125        34.375
Time Constant:          1.54        0.6         1.6          0.6
      1.59          0.61
Percent Charged:        78.63%      45.33%      79.86%       44.86%
   79.55%        45.45%
Cap Voltage:            10007       5769        13551        7611
     16873         9640
Cap Energy (j):         0.45        0.38        1.19         1.01
     2.99          2.56
Energy * Time (j*s):    108         92          286          243
      717           613
Spark length (inches):  28.1        27.2        45.9         44.4
     72.5          70.3

----------------------------------------------------------------------------

Take care,
Bart