Re: arc voltage drops

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

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.
>