[Prev][Next][Index][Thread]
Re: A Puzzle
From: Richard Wayne Wall[SMTP:rwall-at-ix-dot-netcom-dot-com]
Sent: Thursday, September 04, 1997 1:50 PM
To: Tesla List
Subject: Re: A Puzzle
Bert wrote:
snip
>> >The current levels required to support streamer growth are in the
>> >multi-ampere range.
>>
>> snip
>>
>> Bert, have these current levels been experimentally measured and
>> validated in the multi-ampere range?
>>
>> RWW
>
>Richard,
>
>Yes. There's actually quite a large body of research that's been done
>in the area of long-spark "arrested streamers" over the years. These
>experiments typically use a high voltage impulse generator (usually a
>triggered Marx Generator) connected to a rod-plane (non-uniform field)
>test gap.
snip
So, actually all these "arrested streamer" experiments were *not* done
with quarter wave air resonate coils? And, the streamers and arcs
looked like and were dead ringers for Tesla coil discharges? So
naturally it follows that experimentally measured discharge currents in
nonresonate nonquarter wave systems extrapolate to Tesla coil discharge
currents. I would submit that these discharges probably resemble van
deGraf generator sparks also. Incidently, Van deGraf generators
produce exceedingly low current discharges. (Actually, TC discharges
are much like Van deGraf discharges, ie., very low current.) As we all
understand, voltage in a tuned quarter wave resonator reaches its
practical maximum and current approaches zero in the limit at the top
termination.
snip
>I happen to use a 25 watt tubular bulb, but a regular style light bulb
>will also work as well. When the coil is running at full power, the
>bulb is lit by the streamer currents forced to flow thru the bulb and
>"into" the air.
>
>By comparing the degree of brightness with an identical lamp driven
>from a DC source, I found that this corresponds to about 110 mA of
>"average" current.
snip
Again, very subjective measurements. The eye, as well as, the ear are
nonlinear detectors. Also, the intense electrostatic field at the TC
termination causes ionization of gases and illumination in light bulbs.
This will introduce noncurrent error, particurally in a visual
detection system.
A much better method is to use a "current driven device" such as a LED.
Dwayne Bylund has demonstrated very low curents associated at the top
of a resonator coil with serial LEDs along the coil. RH has an
excellent video tape proving that LEDs have good frequency response in
the range of most TCs. An LED coupled to a fiber optic cable will
detect TC current above its threshold. The signal can be calibrated
and compared to a known current value.
RWW