Re: measuring Ls voltage (was Effective Resistance)

["Jim Lux" <jimlux-at-jpl.nasa.gov> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

The problem being that you don't what the secondary impedance is... It's a
LCR combination, with R probably being the most well known of the three.
(and maybe not even that, now that I think about it, because one of the R
components is the loss in corona and sparks).  But wait, there's more, the
LCR of the secondary is coupled to the primary, so the secondary impedance
will have some component of the transformed primary impedance...

Nope, I think the best bet is a calibrated E field probe like Terry's. 
BTW, that's what they use in HV labs and to measure the voltage on things
like Pelletrons and such.  Basically, you have a capacitive voltage
divider.  C from Top load to sensing plate on one arm, and C from sensing
plate to ground on the other.  Then you have to factor in the R and C of
the scope leads in parallel with the lower arm C, but at least you can
calibrate it "in situ".  Put 1 Volt on the secondary from a good low
impedance source at the desired frequency, measure millivolts on your
probe.  Then, read volts on your probe, and calculate back to kilovolts on
the top load.....



----------
> From: Tesla list <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: measuring Ls voltage (was Effective Resistance)
> Date: Sunday, August 27, 2000 11:49 AM
> 
> Original poster: "Bill Lemieux" <gomez-at-netherworld-dot-com> 
> 
>  It has often seemed to me that if one could measure the ground side
current
> (requires equipment capable of measuring RF current, not your average
VOM)
> going into and out of the secondary, that one could calculate the voltage
> across the secondary from its impedance at the resonant frequency.
> 
>  Has anyone played with this?  I seem to recall someone mentioning it to
me,
> but I can't recall who it was- Terry F, perhaps?
> 
> - Gomez
> 
> .........................................................................
> "We cannot live only for ourselves. A thousand fibers connect us with our
> fellow men; and along these fibers, as sympathetic threads, our actions
> run as causes, and they come back to us as effects." -Herman Melville
> 
> 
>