Re: HV meter

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>

Hi Gary,

Often, the ebay 40kV probes are designed for DC measurement. I 
grabbed some "bad" ones cheap (usually an open resistor). Seems the 
resistors come in pairs and usually one of the two is good. I simply 
built a HV divider using the good resistors.

I haven't written anything up on my divider, but basically it's a 
series of 3 resistors (there's a 3rd resistor between the two HV 
resistors). This 3rd resistor is a potentiometer used for calibration 
of which the voltage drop is measured across. I calibrate it by 
measuring a MOT output (ramped up to the highest voltage my 
multimeter can withstand in order to increase the accuracy of the 
divider). I simply use a multimeter across the middle resistor for 
the reading once it's calibrated.

My point is that even those dead DCKV meters are good for parts.

Take care,
Bart

Tesla list wrote:

> Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>
>
> The 40kV HV probes often seen on eBay are usually rated only for DC
> measurements.  I've not tried them on AC, and would be concerned that
> their very high resistance is not compensated for AC use, and may
> deliver misleading results.  Has anyone else tried these probes on 60Hz
> AC?
>
> If you only need to measure a HV transformer, it's best to simply
> measure your mains voltage, apply 120VAC to the secondary, measure the
> resulting primary voltage, and calculate the stepup/down ratio.
>
> Gary Lau
> MA, USA
>
> > Original poster: "Gates" <ryker@xxxxxxx>
> >
> > The meter will be to measure AC voltage from MOT"S ----- Original
> > Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
> >
> > >Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>
> > >
> > >You need to first understand exactly what it it you're trying to
> > >measure.  DC or AC?  60 Hz or high frequency?  100KHz or 100MHz?
> > >Continuous sinusoid or disruptive waveform?  Each of these variants
> > >requires a very different approach.
> > >
> > >Gary Lau
> > >MA, USA
> > >
> > > > Original poster: "Gates" <ryker@xxxxxxx>
> > > >
> > > > Anyone out there have the plans and parts list to make a high
> voltage
> > >meter?
> > > > Please contact me off list.
> > > > Thanks
> > > > Gates
> > > >
> > >
> > >
> > >
> >
> >
> >