Re: Frequency change from due to arcs (fwd)
---------- Forwarded message ----------
Date: Sun, 19 Jul 1998 12:34:39 -0700
From: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Frequency change from due to arcs (fwd)
> I have been playing with this model. How about a capacitor in
> parallel instead of series. Seems to work much better. I have found by
> modeling, here in my cushy armchair :-), that resistance alone cannot
> account for the frequency shift. There definitely is added capacitance from
> streamers at work! The model suggests that the capacitance should be in
> parallel. This makes since to me when I think about the physical situation.
There is an equivalence if the loss is small. A resistor R in series with
a capacitor C is approximately equivalent to a resistor 1/((w*C)^2*R) in
parallel with the same capacitor, at a frequency w (rad/s).
I was considering that a streamer not connected to a grounded object is
effectively connected to a grounded capacitor, as the current must be going
somewhere, acting as a resistor in series with a capacitor.
A more precise model would be a distributed resistor open-ended with a
distributed capacitor to ground, but the nonlinearities have probably
more effect than this modeling detail.
Antonio Carlos M. de Queiroz