Re: Measuring HV capacitor voltage (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sat, 21 Jul 2007 00:34:04 -0500
From: resonance <resonance@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Measuring HV capacitor voltage (fwd)



Drop an ampmeter in the pri side of the nst, or a mA meter in series with 
one of the sec bushings.  When the ampmeter either in pri or sec side goes 
to zero, the caps are fully charged.  In our EM soda can crusher and 
exploding wire devices we use an pri side ammeter rated at 10 Amps with a 
0-100% scale (100% on the left side of dial, 0 on the right).  When the 
charging current reaches the minimum value the meter is indicating 100% 
showing the max charge in the cap.  No current flow = 100% charged and ready 
to fire.

The meter flips over to the max amt on the right indicating 0% charge at the 
start, and then within 12 seconds goes all the way down to the left of the 
dial --- which is calibrated to indicate 100% charge.

I carry these recalibrated, reverse movement meters --- if you need one 
contact me off-list.

Dr. Resonance
Resonance Research Corp.
www.resonanceresearch.com


----- Original Message ----- 
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Friday, July 20, 2007 5:47 PM
Subject: Re: Measuring HV capacitor voltage (fwd)


>
> ---------- 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
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> >
>> >
>>
>>
>>
>
>
>
>
> ____________________________________________________________________________________
> Need a vacation? Get great deals
> to amazing places on Yahoo! Travel.
> http://travel.yahoo.com/
>
>
>
>