Re: Voltagee measurement

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

Original poster: "Jason by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jasonp-at-btinternet-dot-com>

or even how about a variac and a voltmeter?!?!

Jason
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, September 27, 2001 5:12 AM
Subject: Re: Voltagee measurement


> Original poster: "Matthew Smith by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <matt-at-kbc-dot-net.au>
>
> Hi
>
> Someone stop me if I'm making a daft suggestion but: how about series
> resistance and a voltmeter?
>
> Example (not yours - easy figures!):  If we assume a maximum voltage to
> be measured of 10kV and your DMM is rated up 1kV AC, we can use your
> meter provided that we divide the voltage to be measured by 10.  We
> connect 10 x 50MOhm resistors in series, giving an overall resistance of
> 500MOhm.  (Determine resistor power rating by V^2/R =
> 100,000,000/50,000,000 = 2W; higher powered resistors would probably be
> better because their chunkiness would reduce the risk of flashover)
> With ten series resistors of equal value, the voltage across each will
> be one tenth of the voltage across the whole string.  So, whatever you
> read on your DMM should be multiplied by ten to get the input voltage.
>
> Although I might try this on an NST or the like, I don't think that I'd
> fancy hooking this up on the secondary of a Telsa coil; there
> could come a point when the resistors would flash over, unless they are
> specifically designed for EHT use, or are in an oil bath, etc.
>
> Cheers
>
> Matthew
>
>
> Tesla list wrote:
> >
> > Original poster: "Kamil Kompa by way of Terry Fritz
<twftesla-at-qwest-dot-net>"
> <tcmail-at-poczta.fm>
> >
> > Hi !
> >
> > I have a trouble with a transformer. I don't know it's parameters, so I
> > want to measure voltage
> > of the transformer (i think 5 to 20 kV). How can I do this?
> > I found that spark apears between the electrodes connected to the
> > transformer when the gap is about 15mm (between sharp nails) and about
6mm
> > gap is required when electrotes are two spheres (no sharp edges).
> > I know that breakdown in air is about 30V per 0.025mm, but which
distance
> > schould I use for accountings (6mm or 15mm)?
> > I also noticed that when nails aore little wider than 15mm on the top of
> > one of them appears corona. (sparks striking to the air in the direction
of
> > the other nail). There is no corona when I use spheres separated with
more
> > than 6mm of air.
> > Could you tell me something about the output voltage of my transformer
> > having this data?
> > Thanks for all answers.
> >
> > Kamil Kompa
>
>
>