Re: More real experiments

To: tesla-at-poodle.pupman-dot-com
Subject: Re: More real experiments
From: Benson_Barry%PAX5-at-mr.nawcad.navy.mil
Date: Tue, 19 Nov 1996 12:37:00 -0400 (EDT)

Why would you want a larger surge impedance
in the primary tank?
Barry

 ----------
|From: "tesla-at-poodle.pupman-dot-com"-at-PMDF-at-PAXMB1
|To: Benson Barry; "Tesla-list-subscribers-at-poodle.pupman-dot-com"-at-PMDF-at-PAXMB1
|Subject: Re: More real experiments
|Date: Sunday, November 17, 1996 2:50PM
|
|<<File Attachment: 00000000.TXT>>
|From lod-at-pacbell-dot-netSun Nov 17 11:50:50 1996
|Date: Thu, 16 Nov 1995 14:12:00 +0000
|From: lod-at-pacbell-dot-net
|To: tesla-at-pupman-dot-com
|Subject: Re: More real experiments
|
|Richard Hull wrote:
|
|
|> Well gang,
|>
|> I have been busy over the weekend with my Pearson current monitor and
|> capacitive HV voltage divider.  I physically measured the voltge across
|> the gap and current through it while the coil was in operation.  In an
|> effort to find the power consumed by the gap in operation.
|
|[snip]
|
|> Analysis:
|>
|> Due to my using a variac and only allowing the AC line voltage to reach
|> 28 volts in to the neon's primary, I measured a peak voltage out from the
|> transformeers secondary of 2640 volts.
|>
|> This showed up as the max voltage across the non-firing gap.  Firings at
|> the gap showed a rather immediate fall to ~200 volts.  The  current
|> transformer indicated a peak current in the system at this point of ~80
|> amps.  Thus under the optimal conditions the gap had a lowest possible
|> resisitance of 2.5 ohms. (The gaps were hardly making any noise!) For the
|> instant of max turn on, the gap consumed 16,000 watts of peak energy.
|> The peak tank energy in our little 15VA system would have been on the
|> order of 160,000 watts. based on a 2KV firing point and 80 amp tank
|> current.  10% losses figured this way.
|>
|> The scope was set up to yeild a mathed third trace as A X B  yielding
|> volt amps.  This was intergrated by hand with time to yield a total sine
|> consuption of energy on the order of 1.6VA.  With the power factor
|> corrected primary hooked to a watt meter we read 15.1 VA while the system
|> was on (auto integrating).  This shows that we lost about 10% of the
|> input energy in the gap on average.  Another cross confirmation.
|
|
|Interesting experiment!  Did you try the same msmt at other power levels?
|I'm curious as to how the arc resistance will vary as the current is
|increased.
|On your six-gap tungsten sparkgap, what was the total gap distance?
|
|To add another data point, I tried a similiar msmt on my coil, and came up
|with
|a total gap resistance of 0.65 ohm for a 4-gap system, at about 1.8 kA.
|The total gap distance in this case was 0.060".  I would've expected the
|0.65 ohm value to be much smaller, since the arc channel is supposed to get
|fatter as the current increases, but apparently it doesn't grow so fast 
after
|all.
|I was expecting a gap resistance of 0.25 ohm!  If I had known these numbers
|before
|I had built my coil, I would have laid out the primary ckt quite 
differently,
|so
|that it would've had a larger impedance [SQRT(L/C)].
|
|-GL
|