Re: arc voltage drops

["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 Jim, all,
             One must remember that in a TC, the current used in the 
is a (sinusoidal) function of time, not a DC value and will give 
other than a steady resistance when plugged into the equations.

Regards,
malcolm


On 9 Apr 2002, at 1:24, Tesla list wrote:

> Original poster: "Shaun Epp by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<scepp-at-mts-dot-net>
> 
> Can you elaborate on these equations.
> 
> The values that you use, are these an example?
> 
> Shaun Epp
> 
> 
> ----- Original Message -----
> From: "Tesla list" <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Monday, April 08, 2002 7:17 PM
> Subject: arc voltage drops
> 
> 
> > Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <jimlux-at-earthlink-dot-net>
> >
> > I just ran across an equation that may be useful for those of you
> > simulating spark gap losses.
> >
> > It comes from Khalifa, High Voltage Engineering, page 153
> >
> > Steadystate DC arc voltage
> > V = a + b*length + (c + d*length)/current
> >
> > where typical constants for air, up to 5 cm length, and arc currents up to
> 20A
> >
> > a = 17V
> > b = 22V/cm
> > c = 20Watt
> > d = 180W/cm
> >
> > For a general energy balance standpoint... E = C*I^(-1/3)
> >
> > The following pages discuss some issues about AC arcs.. having to do with
> > temperature of the arc column (i.e. the resistance) lagging the voltage.
> >
> > They cite Cassie and Mayr (separately) to come up with an "arc resistance
> > after current zero" relation of the form:
> >
> > R d/dt 1/R = 1/theta *[ (VI/W)-1)
> >
> > There is some discussion about "quenching" in the sense that you can
> > determine from an energy balance whether the arc will reignite after a
> > current zero.
> >
> 
> 
> 
>