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Re: Light Bulb Experiment (Followup)
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> From: Tesla List <tesla-at-poodle.pupman-dot-com>
> To: Tesla-list-subscribers-at-poodle.pupman-dot-com
> Subject: Re: Light Bulb Experiment (Followup)
> Date: Tuesday, October 01, 1996 11:25 PM
>
> > Subject: Light Bulb Experiment (Followup)
>
> >From sgreiner-at-mail.wwnet-dot-comTue Oct 1 21:51:47 1996
> Date: Tue, 01 Oct 1996 11:52:48 -0700
> From: Skip Greiner <sgreiner-at-mail.wwnet-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: Light Bulb Experiment (Followup)
>
> Tesla List wrote:
> >
> > >From bert.hickman-at-aquila-dot-comSat Sep 28 10:13:58 1996
> > Date: Fri, 27 Sep 1996 23:24:14 -0700
> > From: Bert Hickman <bert.hickman-at-aquila-dot-com>
> > To: tesla-at-pupman-dot-com
> > Subject: Light Bulb Experiment (Followup)
> >
> > Here's a "Light Bulb Experiment" and toroid-ground discharge update:
> >
> > Previously, I had used various sizes and wattages of light bulbs placed
> > in series with the corona current path. These lights unexpectedly
> > "dimmed" when passing heavier toroid-ground discharge currents. Dave
> > Huffman and Robert Stephens theorized that these higher current
> > discharges were bypassing the filament path due to unseen arc-overs
> > between the lamp-base leads. And after a few more experiments, I
> > concurred, but had no direct proof.
> >
> > I just tried a slightly different experiment using a 100 Watt tungsten
> > halogen lightbulb. This bulb is about 2" long x 1/4" diameter, with the
> > filament going the length of the bulb, and having a ceramic & metal
> > termination at each end. This particular construction prevents any
> > flashovers, forcing both the corona and ground surge currents to flow
> > through the filament. Because of the larger filament wattage, I was
only
> > just barely able to light the bulb when running streamers to air
through
> > the filament. However, once toroid-ground discharges began between the
> > free end of the lamp and a grounded wire 42" above, the filament began
> > to glow fairly brightly.
> >
> > This helped confirm that the previously observed dimming associated
with
> > Mazda-based lamps was indeed an artifact due to the heavy current
arcing
> > around and bypassing the filament. I very carefully observed the
average
> > brightness of the bulb under the heavy-discharge condition while
running
> > the coil at maximum power. I then connected the same bulb to a variac
> > and an AC ammeter to estimate the average current necessary to light
the
> > bulb to an equivalent degree. This level was reached at about 400 MA,
> > implying that the lamp was seeing an "average" current level of about
> > 400 MA during the ground discharges (sort of like a hot-wire
> > ammeter...).
> >
> > Further measurements with a storage scope showed that each
> > toroid-to-ground discharge removed virtually ALL of the energy in the
> > Primary/Secondary system in a very short time. There was no further
> > ringdown, or any other activity until the next "bang". Each discharge
> > occurred near the first peak of secondary voltage (i.e., during the
> > first energy transfer/"Bang"). Each high-current discharge actually
> > consisted of an exponentially damped 10-20 MHz current, with virtually
> > all of the energy being dissipated in about 1.5 uSec. At full power,
the
> > primary gaps fire 3 to 4 times every half cycle, or between 360 and 480
> > PPS. For analysis purposes, an average rate of 420 PPS will be used.
> >
> > Using 420 PPS, with each toroid-ground current surge lasting only 1.5
> > uSec, the total time "ON" time per second is about 420 x 1.5 uSec or
630
> > uSec, implying a duty cycle of only about 0.063%. The toroid-ground
> > current peaks which would have to flow to "average" 400 MA can now be
> > estimated: Isurge=(0.400)/(630x1e-6) or about 635 Amps(!). However,
> > since the actual current surges are exponentially decaying during each
> > 1.5 uSec shot, the actual current peaks are probably significantly
> > greater than 1000 Amps(!).
> >
> > This explains why these discharges look so mean and evil... they ARE!
> >
> > As always, flames, brickbats, and snickering are always welcomed. <:?)
> >
> > Safe (and rubber-booted) coilin' to ya!
> >
> > -- Bert --
>
> Bert
> This is neat stuff but I think one more measurement needs to be made. I
> have a major problem in believing that the filament will actually take a
> 1000 amp pulse. I think a controlled test dumping a 1000 amp pulse of
> the prescribed 1.5 usec pulse duration thru the lamp to see if the lamp
> will actually live would help to bolster your conclusions.
>
> Skip
Hi All,
Just my two cents here ;>) I was involved in a test once where we pulsed a
section of superconducting wire, 22ga I think, for a few milliseconds. The
wire was not in the superconducting phase but was at LN2 temperatures and
therefore was basically a copper wire. I was amazed that we could pulse it
to about 1000Amps without it fusing. I can believe that a filament could be
hit with 1000Amps for a much shorter time (uS) and survive. It would also
seem that you would need the output of a TC to pulse the filament to
1000Amps. 1000A*100ohms=100KV
This is interesting stuff!
dave