From: "Terrell W. Fritz"
Date: Tue, 08 Oct 2002 20:29:38 -0600
Subject: Re: [TSSP] Top Voltage
Hi Paul,
First, I measured the "bare" secondary's Q with and without an 8 inch extra
SonoTube inserted inside it. Then I inserted the extra 8 inch tube inside it.:
PK FREQ kHz (Error +/-) Q FACTOR (Error +/-) LEVEL
1 52.120 (0.01%,7Hz) 63.97 (0.25%, 0.2) -0.6dB
2 126.034 (0.01%,16Hz) 38.96 (0.83%, 0.3) -11.4dB
3 180.233 (0.01%,23Hz) 32.15 (2.35%, 0.8) -15.1dB
4 229.310 (0.01%,29Hz) 29.38 (5.58%, 1.6) -18.4dB
5 276.806 (0.01%,35Hz) 26.43 (13.28%, 3.5) -22.1dB
6 328.292 (0.01%,41Hz) 27.83 (22.33%, 6.2) -26.5dB
Accounted for 98.85% of input signal
PK FREQ kHz (Error +/-) Q FACTOR (Error +/-) LEVEL
1 51.793 (0.02%,11Hz) 43.07 (0.99%, 0.4) -0.6dB
2 123.593 (0.02%,25Hz) 26.43 (0.83%, 0.2) -11.6dB
3 174.229 (0.02%,36Hz) 22.11 (2.79%, 0.6) -15.5dB
4 220.807 (0.02%,45Hz) 21.13 (5.58%, 1.2) -18.0dB
5 268.222 (0.02%,55Hz) 20.18 (9.39%, 1.9) -20.8dB
6 319.881 (0.02%,66Hz) 20.69 (13.28%, 2.7) -25.2dB
Accounted for 99.26% of input signal
http://hot-streamer.com/temp/OLTC10-08-10.CSV
http://hot-streamer.com/temp/OLTC10-08-10.gif
http://hot-streamer.com/temp/OLTC10-08-11.CSV
http://hot-streamer.com/temp/OLTC10-08-11.gif
This extra tube has been sitting around here for about a year so it is "dry".
But it still has a big effect.
I hooked up two 56nF caps with an 1100V MOV to the base of the coil (with top
terminal and all now):
http://hot-streamer.com/temp/OLTC10-08-14.gif
The capacitance was 0.1116uF and Vfire was always 300VDC. The break rate was
0.2Hz. Many times the coil did not seem to breakout and I got no offset on the
cap:
http://hot-streamer.com/temp/OLTC10-08-12.gif
But about 30% of the time it did break out:
http://hot-streamer.com/temp/OLTC10-08-13.gif
I got the following typical offsets when that happened: -2.2, -4.2, -3.8, -0.6,
-4.7, -3.8, -4.2.
They were always negative and seemed to max out at about -5 volts. I have not
thought about the greater meaning here but I just report ;-)) Here are some
pics too:
http://hot-streamer.com/temp/OLTC10-08-01.jpg
http://hot-streamer.com/temp/OLTC10-08-02.jpg
http://hot-streamer.com/temp/OLTC10-08-03.jpg
Next I'll work on this average top and bottom probe current stuff...
Cheers,
Terry
At 08:52 AM 10/8/2002 +0100, you wrote:
>Marc wrote:
>
>> The space charge is a very strong field i think.
>
>Terry wrote:
>
>> I am thinking the toroid is breaking out all over and
>> "poisoning" the space around the small top ball with flying
>> ions.
>
>If space charge is having an effect, we should be able to
>detect it by noticing a change to the effective C of the
>topload, and this would occur before the visible breakout.
>
>Terry, I'm hoping you can measure the average rod+sphere
>probe current and the average sec base current, for various
>power levels leading up the observed breakout. Plotting
>probe current against base current way show a tell-tale
>deviation from the straight line as the power goes up.
>
>We can also try to detect a rectification of top terminal
>current.
>
>A cap of 0.1uF in the base would have around 40 ohms reactance,
>so at most a 50-100 or so RF volts across it. If breakout
>occured, the DC charge that accumulates on this cap would be
>equal to the total net rectified charge put out by the topload.
>
>At most, if the entire firing energy was rectified and stored
>in the 0.1uF cap, you would have Vfire * sqrt(47uF/0.1uF) DC
>volts on the cap, so you could end up with a few kV. That's
>just one bang. If you allowed charge to accumulate over more
>bangs, the voltage could continue to rise.
>
>Can I suggest around 0.1uF with a 2.5kV Victoreen gap across it
>to dump any excess DC?
>
>--
>Paul Nicholson,
>--
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.