From: "Terrell W. Fritz"
Date: Sun, 22 Oct 2000 20:03:49 -0600
Subject: Re: [TSSP] NSVPI - Early Results
Hi Richard, At 11:42 PM 10/22/2000 +0100, you wrote: > >Terry, Paul, all > >What do we expect to see as the drive power to the resonator is increased? >The approximately sigmoid graph might steepen at the top as breakout occurs >and the forward current increases, dropping more volts across turns perhaps. > >There is a fair way to go before the corona inception voltage is reached, >but that is the point at which the system becomes very non-linear. How much >corona current do you think will be drawn out of the coil into the sampling >device? If the difference V across your sampling probe doesn't exceeed the >tiny capacitance, then maybe samples at CIV or above could be taken. If my CW coil is putting out say 50kV and I divide it's length up into 25 sections. Then each would see an average of 2kV. The peak in some areas may be 5kV/section! An obvious problem is getting a capacitor that could take that. There are some RF types that could without leakage but the values tend to be small like 100pF. That would make the ionization a serious factor. If my big coil hits 300kV peaks, that gives a multiplier of 300000/70= 4286 for what I measure now. So if I get 3 volts now, I would get around 13kV in operation!! Unfortunately, that is probably far beyond what such a probe could handle. An inline current sensor would have a far better chance of surviving that. So maybe that is a way to see the inner working of the secondary of an operating coil. > >If the local disturbance due to the probe is kept small (low Er dielectrics, >minimal metal and no sharp edges etc.) then it may be a practical >proposition to probe at near real-life powers. >From my experience and in light of the above, I would think that directly probing an operating coil is not practical with such a voltage probe. However, the current profile seems very interesting from Paul's simulation! Current is far easier to play with in high voltage stress fields. That would take a special coil and all but I think there are no big problems... > >I realise that this is jumping the gun but I'm just thinking out loud >(dangerous, I know!) No Problem! It is cool we have some new things to think about now!! BTW - I will not get to my loaded secondary measurement tonight. I have gotten hung up playing with the test setup stuff.... Cheers, Terry > >RMC >
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.