Re: Measuring HV capacitor voltage (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 20 Jul 2007 14:01:15 -0700 (PDT)
From: Yurtle Turtle <yurtle_t@xxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Measuring HV capacitor voltage (fwd)

Do you charge it from an NST with rectifiers and a
variac? If so, you could measure variac output, and
calibrate the scaling using your HV probe. Of course
this wouldn't tell you when you're fully charged.

I use the 5 volt output from my HVDC YAG PSU in my
canabalized VTVM:

http://hot-streamer.com/adam/garage/psu_34kV_1.jpg
http://hot-streamer.com/adam/garage/psu_34kV_2.jpg
http://hot-streamer.com/adam/garage/psu_34kV_3.jpg

Adam

--- Tesla list <tesla@xxxxxxxxxx> wrote:

> 
> ---------- Forwarded message ----------
> Date: Fri, 20 Jul 2007 14:29:51 +0000
> From: David Rieben <drieben@xxxxxxxxxxx>
> To: Tesla list <tesla@xxxxxxxxxx>
> Cc: drieben@xxxxxxxxxxx
> Subject: Re: Measuring HV capacitor voltage (fwd)
> 
> Hi Bart,
> 
> Yes, a high voltage probe that plugs directly into
> your DVM
> is the most convinient way to measure HV. I do
> already have 
> one of these and was using it to try to calibrate my
> "attempts" 
> at a voltage divider. However, I need a more
> permanent panel
> mount meter for measuring the voltage across my huge
> quar-
> ter shrinker caps so that I don't overvolt them. I'd
> really ra-
> ther not have to be sticking that probe by hand onto
> the
> "hot" terminal of a fully charged 20 kJ capacitor
> bank each 
> tiem that I charge them up ;^() I need a safer and
> more per-
> manent hardwired metering setup.
> 
> 
> David Rieben
> 
> -------------- Original message -------------- 
> From: "Tesla list" <tesla@xxxxxxxxxx> 
> 
> > 
> > ---------- Forwarded message ---------- 
> > Date: Thu, 19 Jul 2007 01:21:24 -0700 
> > From: Barton B. Anderson 
> > To: Tesla list 
> > Subject: Re: Measuring HV capacitor voltage (fwd) 
> > 
> > Hi David, 
> > 
> > A little while back I documented a hv divider: 
> >
> http://www.classictesla.com/download/hvacdivider.pdf
> 
> > 
> > I however broke one of the resistors and decided
> to simply buy some hv 
> > resistors and give them a try. I ordered from
> Allied Electronics p/n = 
> > 296-0171 (the manufacturer is Ohmite who's p/n is
> EX2G1006). I just 
> > checked the website and it seems that part number
> is no longer listed? 
> > Odd. It's a pc board mount type. If you can
> imagine a 10 pin sip 
> > resistor with only pin 1 and pin 10 at their ends,
> this is what the 
> > resistor looked like. Was good for a hefty 10kV
> however. I think it was 
> > about 300M. It may not be available any longer?
> Anyway, something along 
> > that line can be used. You just have to alter the
> center voltage divider 
> > to suit. 
> > 
> > Of course, the best way to measure is just to do
> an eBay search for a 
> > high voltage measurement probe for high "AC"
> volts. Their out there. A 
> > lot easier than building a divider and the cost is
> likely pretty similar 
> > in the end. 
> > 
> > Take care, 
> > Bart 
> > 
> > 
> > 
> > Tesla list wrote: 
> > 
> > >---------- Forwarded message ---------- 
> > >Date: Thu, 19 Jul 2007 15:15:51 +0000 
> > >From: David Rieben 
> > >To: Tesla list 
> > >Cc: drieben@xxxxxxxxxx 
> > >Subject: Measuring HV capacitor voltage 
> > > 
> > >Hi all, 
> > > 
> > >I'm having a little issue with measuring up to 10
> kV across a capacitor 
> > >on a standard panel mount, analog 0-15 VDC
> voltmeter from Radio 
> > >Shack. Obviously, I was trying to make it read 1
> volt for each measured 
> > >1000 volts. I tried using a voltage divider of 10
> seriesed 10 meg resistors 
> > >and a 100 K pot but found that the 100 megs was
> just too much resist- 
> > >ance to allow for sufficient current for reliable
> movement of the volt meter. 
> > >I then tried a series-parallel arrangment of
> 10x10 of the 10 meg resistors 
> > >for a total of 10 meg and then still used the 100
> K pot and varied it to try 
> > >to bring in the proper calibration. I was
> checking the voltage measurement 
> > >with my HV probe and DVM. The resistors didn't
> like being bunched up 
> > >10 at a time and started flashing over
> externally. Also, I was having trouble 
> > >getting the analog meter readings to be accurate
> throughout the 0 - 15 volt 
> > >range according to the measurement of the HV
> probe. I think the meter is 
> > >designed for 10 meg impedance and it also comes
> with a 15 K resistor that 
> > >is supposed to be in series with the voltage
> source. Anyone have any sug- 
> > >gestions for reliable and reasonably accurate
> measurement of high voltage 
> > >through a low voltage analog voltmeter via a
> voltage divider network? 
> > > 
> > >Thanks 
> > >David Rieben 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > > 
> > 
> > 
> 
> 
> 



       
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