Measurements using field probe
From: Bert Hickman [SMTP:bert.hickman-at-aquila-dot-com]
Sent: Wednesday, June 24, 1998 10:17 PM
To: Tesla List
Subject: Re: Measurements using field probe
Tesla List wrote:
> From: terryf-at-verinet-dot-com [SMTP:terryf-at-verinet-dot-com]
> Sent: Wednesday, June 24, 1998 6:44 PM
> To: Tesla List
> Subject: Re: Measurements using field probe
> Hi Bert,
> Thanks for the note about the bad pointer. It should be fixed now.
> The pointer changed to:
> This is a newer version that has a bunch of typos fixed.
> I have been busy this week and haven't been able to play much with higher
> power strikes. I don't have much I would like to comment on now but there
> are many things I need to look at. The very high voltage stresses and where
> the missing energy is going are two. More latter.
> I would like to know about your light bulb experiment. How is was set up
> and what happened?
> I would also like to know where you disagree with the conclusions and why?
> Perhaps something was not explained well or there is something I need to
> look at closer.
> Thanks for your interest.
> Terry Fritz
Terry and all,
First, I need to apologize - the message I sent was intended to be a
private e-mail to Terry, but I accidentally sent it to the whole list.
I've attached a copy of one of the "light bulb experiments" done in 1996
at the end of this message.
Terry, your papers were very well done, as was your research work. There
are only a few areas where I may not agree with all of the conclusions.
These tend to be areas where there may need to be some additional
experiments. I'll follow up on these in another post or two. In the
meantime, here are a couple of the experiments...
-- Bert --
Subject: Light Bulb Experiment (ala Brent Turner)
Date: Sun, 15 Sep 1996 14:31:17 -0700
From: Bert Hickman <bert.hickman-at-aquila-dot-com>
References: 1, 2
> Tesla List wrote:
> > > The 'banjo' effect images are quite striking and beautiful, plus
> > > there are a few others showing myself sitting atop an insulated
> > > table tossing 4 foot sparks off metal rods and my fingers! (BTW
> > > I am wearing chain-mail meat cutter's gloves which are connected
> > > to the table via wires hidden in my sleeves.)
> > >
> > > - Enjoy!
> > >
> > > - Brent
After looking at Brent's picture (BRENT_1.JPG) showing a 40W bulb being
lit from current coming off his coil, I decided to replicate this on my
10" coil (without me being an integral part of the experiment. ;^) I
took a standard 120V ceramic light socket and mounted it to a piece of
wood. A short piece of magnet wire was connected to one terminal of the
socket, and the other end was run to the reverse side of the wood block
and secured with a piece of conductive aluminum heating-duct tape. The
other socket terminal ran to a 1 foot piece of HV wire. By setting the
assembly on the top of the toroid, I could position it so that the loose
end of the HV wire just poked out from the outer edge of the toroid. Any
current flowing through the corona would flow through any light bulb
screwed into the socket.
I then proceeded to try various sizes of incandescent light bulbs to see
if they would light from the current drawn by the corona coming off the
HV wire. Although a 40 W bulb would light (orange color), I got the best
results from 15 and 25 Watt bulbs, lighting them to almost full
brilliance. I also succeeded in blowing out the filament of one 15 watt
bulb - this bulb had a filament that started jumping all over the place
once current started flowing through it, and it finally just openned up.
I'm also thinking about getting one of those trick "party" bulbs that
has a dancing filament to see how it would work.
Anyway... I made an interesting discovery: If I had a fairly steady
streamer that didn't arc to gound, the 25W bulb lit up at a fairly
bright and constant level. However, once I got heavy discharges to
ground, the brightness level declined significantly, and my AC primary
current climbed from about 22A to >28A off the 120V main. I don't
understand why this should be! I would have expected that the bulb would
brighten, since the discharge current to ground clearly seems to be much
higher than the corona streamers. The fact that my primary current
climbs also would suggest that I am processing more power under this
Some other information that may be relevant... the system's 15 KV 120 MA
neons and tank cap resonate at about 60 Hz (by design), and I'm using
about 170 uF of PFC capacitance. The gaps are a combination of static
and vacuum, totaling about 0.54".
Any ideas about what is going on??
-- Bert --
Subject: Light Bulb Experiment (Followup)
Date: Fri, 27 Sep 1996 23:24:14 -0700
From: Bert Hickman <bert.hickman-at-aquila-dot-com>
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
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 --