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Re: Infinite Q almost
Tesla List wrote:
>
> >From jim.fosse-at-bdt-dot-comThu Sep 5 06:56:32 1996
> Date: Thu, 05 Sep 1996 05:37:03 GMT
> From: Jim Fosse <jim.fosse-at-bdt-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: Infinite Q almost
>
> >From: Richard Hull <hullr-at-whitlock-dot-com>
> >To: tesla-at-pupman-dot-com
> >Subject: Infinite Q almost
> >
> pre.script: Your addendum post arrived before this original;)
> (chip, did you get overloaded this weekend?) Chip answered my
> question whilst I was writing it. Message 30 or 40 for tonight came
> in!
>
> [snip]
>
> > I did away with the primary tank circuit and just
> >used a DC 15KV supply with the positive lead to a spark gap and negative
> >to ground. The other side of the gap went to a resonator which could
> >have its terminal loading altered dramatically. The system, when in
> >operation, drew and averaged DC current from the supply of .1-.5 ua!!!
> >(1.5-7.5 milliwatts.) The spark in the 1mm gap inaudible and invisible
> >in normal room light
>
> [snip]
>
> I just spent 2 hours in the garage playing with this and several veri
> ants.
>
> I've only a 1.5kV -at- 5mA DC supply (others that are up to 45kV are all
> switch mode. to much RFI for good measurement). I gaped a spark plug
> down to fire at this voltage. connected it in series between the
> negative power supply lead (+ = case) and then to my TC's lower
> secondary connection. I connected the case of the power supply to my
> earth ground. The TC secondary was terminated with my 3" by 27"
> toroid.
>
> I rigged an antenna into my TEK 465 scope: 3' clip lead ~6' from my
> toroid. At power up I saw 1 big RF spike (10V scale) and then nothing.
> My toroid will not break down at 1.5kV;) (good news) I tried various
> methods to generate a corona point from my toroid including a medical
> "lance" about 4" connected but away from the toroid. I still could not
> see any RF above ambient. I approached my toroid with my ground
> discharge rod until breakdown occurred. 1/10"? The scope picked up
> about 50 volts RF, but I was to far away to get an accurate reading.
>
> I then added a 75 Mohm resistor from the gap/resonator junction to
> ground. This caused the spark gap(plug) to break down and generate a
> repetitive oscillation that I could measure. 2 volts RF on a 40V
> negative exponentially decaying waveform of 6ms period. (The RF had a
> 6us period) I could not determine the end of the RF oscillations, they
> were lost in the 60Hz and 810kHz ambient.
>
> I also tried a 4' fluorescent light as a gap. It lit, but I could not
> see any RF above the ambient.
>
> Good experiment.
>
> jim
Jim,
With the low voltage you used, it is little wonder your gap wouldn't
fire. I had to supply 15KV just to jump 1mm! This utilized the
toroid to ground air impedance (teraohms) as the resistance return to
ground and as the charging resistor of the Cinternal and Cterm
capacitance.
Richard Hull, TCBOR