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Re: TC potential measurements
Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
At 06:21 PM 3/15/2005, you wrote:
Terry's planar antenna and a 200 kV DC power source gave us good calibration
which we compared to the spark length measurement method. We use a 7" dia
Van de Graaff sphere for most of our measurements. We used a 14" dia sphere
for the large coils with toroids in excess of 4 ft dia.
Values were in very close agreement.
Glad you are enjoying the little plane antenna so much ;-)) For those
interested, the details are here:
Even our Big Bruiser with it's 26 ft. long spark at 26 kVA was only
developing 865 kV! We thought it was over a megaVolt but measurements
provided the truth.
At first I worried that models were predicting such low voltages... But it
proved to be correct.... In the case of Bruiser, just round to the nearest
MV :o))) I think Bill's #13 is rated 25MV ;-))
The DRSSTC makes streamer formation of low voltage little arcs building
along a path formed by the previous arcs to form the big arc pretty
obvious... "Disruptive" or pulsed arcs are now well known to arc at far
greater distance than the equivalent CW cases...
Marco now seems to have achieved the real "holy grail" and has a system
going that can directly measure TC output voltages at high bandwidth
without loading down the coil oddly!!!
Ross Engineering also manufactures NBS standard traceable voltmeters
accurate from DC to 1 MHZ and potentials up to 1 million Volts. Not cheap
but very accurate.
I "think" they are messed up by being near very high voltage AC
fields... The measurement active columns are not shielded to the extent
need to be immune from high dV/dL near them... But Marco an Paul seems to
have things figured out (or they will real quick now ;-)).
In a short time, we will have some very accurate data to ponder!!! We also
have OLTCs and DRSSTC that can reproduce sparks to stunning accuracy and
can be fiddled with quite independently of all those things that used to
annoy us so much!!
But now worries. It will still be some time before National has a TC in a
16 pin DIP ;-)))