Re: tesla coil model

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

Original poster: Redmo-at-aol-dot-com 

Thanks Antonio, for checking my simulation results. I added calculations to 
integrate the losses in the primary and secondary resistors from time of 
spark gap firing to first notch and got:
energy loss in primary (r1) = .18 joule
energy loss in secondary (r2) = .02 joule
with so much energy being lossed in the spark gap, I think spark gap 
resistance reduction could be a major performance improvement area. The 
rotory spark gap may do this somewhat by moving the electrodes closer to 
each other that the static gap for the same firing voltage. However as we 
all know, computer simulations are only as good as the models they are 
based on. Modeling the spark gap as a simple resistor may not be very good. 
I read somewere that the spark gap may have a somewhat constant voltage 
drop across it when it fires, is this true?

Thanks, Russ

> > I first checked the model with the no loss case: r1 = r2 = 0. and k = .105
> > , I assumed primary capacitor was charged to 10 kv when the spark gap fired
> > ( t = 0.) the results were v2 (q2/c2) max = -265.5 kv at time = 7.32 uSec.
>
>Agrees with my simulator Teslasim.
>(http://www.coe.ufrj.br/~acmq/programs)
>
> > this v2 value agrees with v2 max = 10kv*sqrt(c1/c2) and the plot of v2,v1
> > vs time shows the first notch at 5 cycles, which agrees with theory for k =
> > .105
> > I next ran the same case with r1 = 2.07 ohms and r2 = 220 ohms. the results
> > were: v2 max = -171.9 kv at time = 5.78 uSec.
>
>Agrees too.
>
> > what I found interesting was:
> > 1) The energy of the case with losses was 42% of the no loss case.
>
>Ok too. Note that almost all the loss is in the primary resistor, and
>that if you increase k the losses are smaller.
>
> > 2) The first notch for the case with losses was earlier than the no loss
>case.
>
>Because some energy was lost before being transferred.
>
>Antonio Carlos M. de Queiroz