jul15-94.txt

To: tesla
Subject: jul15-94.txt
From: chip (Chip Atkinson)
Date: Tue, 1 Nov 1994 13:17:19 +0700

Date: 06-28-94 13:41
From: Dave Halliday
To: Richard Quick
Subj: Tesla Coils
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Hi Richard

Just dropping a note to let you know that I am still incredibly
busy at the store but I plan to have the coil up and running in
about a month or so.

I finally broke down and hired another full-time person so I can
go back to "normal" 8-10 hour days... sheesh...

Also, I was wondering about the current regulation going into the
pole pig - you are using an arc welder. I have several baseboard
heaters and I was thinking of paralleling a couple of those -
lossy but hey!

The work on the controller is going well - I have not hooked it
up to the variacs yet - it's still at the store but it works
well. I had done some other projects using that CPU so I still
had some development boards left.

Anyway, I will keep you posted (206) 528-1941 (1:343/210)

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Date: 06-30-94 16:14
From: Richard Quick
To: Terry Smith
Subj: 10KVA Tesla Coil
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-=> Sez Terry Smith to Richard Quick <=-

TS> I've noticed you've taken pains to document several aspects
TS> of your work well, and that made me curious if you've tested
TS> other parameters which have either not been mentioned, or
TS> which I've failed to notice discussed here. In arcing
TS> resonant circuits, how closely does output track input?
TS> (Input, I assume, is safer and easier to monitor directly?)

Ooohh, I'd say you have to be a little more specific with this
question before I could tender a reply. How closely does output
"track" input?

TS> Outside of commercial environments, few people are equipped
TS> to monitor induced and radiated fields quanitatively. I was
TS> hoping you'd know of such studies by someone, if not equipped
TS> to measure that aspect of large coil operation yourself.
TS> (Impress me... Are you?)

Impress you? Please Terry, spare me. To answer your question...
This work was done by Tesla 100 years ago, and without the
"commercial environment" you refer to. Please get a copy of
Tesla's COLORADO SPRING NOTES.

TS> As to the 6.78 MHz or other ISM frequencies, I strongly
TS> suspect that imitation lightning is inherently too wideband
TS> to possibly be confined to such allocated legal spectrum.

RQ> BTW, where did you come up with this frequency???

TS> 47CFR18.301 (FCC ISM Regs, where unlicensed signal
TS> strengths are conditionally unlimitted) Doesn't everyone
TS> have a copy on the bookshelf by their computer?

As I thought, this is completely unrelated to Tesla coils. I
rarely operate over 500 kHz.

TS> If emmisions could be confined to a narrow bandwidth, the
TS> need to suppress signal transmission could be made moot.

Oh really, can I quote you on this?

TS> ... control bandwidth...
TS> ... regulate the effective frequency of an arc

TS> Quite frankly, I'm amazed that megawatt surges haven't
TS> caused neighbors problems.

RQ> I am sorry to disappoint you.

TS> I've noticed in other posts discussion of coils large enough
TS> to need a 60x80x50 foot bonded steel structure to house but
TS> suppress the output of some coils.

Where??? You mean I missed it??? Or was I the one posting?

TS> This would be beyond what's available to hobbiests
TS> without unusual means...

Most people don't build coils that require such enclosures; those
that do are sufficiently advanced to see the need for one.

TS> and I have noticed emphasis at times on avoiding the cost of
TS> commercial vacuum or G type mica capacitors.

Must I go through this again? These caps (mica, vacuum) are poor
performers in these circuits, regardless of cost. Cheapy home
built poly/oil caps perform much better... at half the cost. Salt
water capacitors work nearly as well for no cost. Get it???

TS> If you've conducted the operations described here, and
TS> suppressed both RF complaints and regulatory violations, I'm
TS> impressed, rather than disappointed.

And I tried so hard not to impress you...

Sparking Tesla coils are poor broadcasters of RF energy. Damped
waves just don't radiate well to start with, and most of the
energy gets consumed in the discharge when coils are properly
tuned for spark. Preventing spurious emissions on larger, more
powerful coil systems, or systems operating as transmitters for
experimental work, is as simple as enclosing the coil area in
hardware cloth, aluminum foil, or other conductive material, and
the grounding the enclosure. I was blessed with a work area that
is earth or earth berm on five sides; the sixth side is metal
faced and can be grounded simply and easily. Proper line
filtering and grounding prevents the 60 cycle power lines from
becomming antennas.

Inside the coil area all kinds of interference; inductive,
conductive, and radiated; can be significant. Outside the coil
area, TV's, radios, cable, telephone, etc., show only the
slightest sign of leakage (I am talking high powered or radiant
operation, and very short distances). By the time you get 50 feet
away there is no significant signal, certainly nothing to worry
the FCC or any other regulatory body. As I have stated many
times... I get complaints about the noise, but never about EMI.

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Date: 06-30-94 16:15
From: Richard Quick
To: Brian Thurston
Subj: TESLA
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BT> Hi Richard:

BT> A very concise and succinct statement of the events
BT> concerning Tesla and his AC transmission systems.

Thank you very much Brian.

BT> My only additional fact is that Tesla died pennyless in
BT> Canada still trying to develop his wireless energy
BT> transmission system into a commercial product.

OK, we agreed he died pennyless. But he did reside in New York,
and was in the city by all accounts when he died.

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Date: 07-01-94 23:17
From: Richard Quick
To: Dave Halliday
Subj: Tesla Coils
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DH> Just dropping a note to let you know that I am still
DH> incredibly busy...

Yes I knew you were out there lurking, and figured you were
overworking yourself. I hope you have been saving stuff.

DH> I was wondering about the current regulation going into the
DH> pole pig - you are using an arc welder. I have several
DH> baseboard heaters and I was thinking of paralleling a couple
DH> of those - lossy but hey!

Well, there is no doubt that using pole pigs in experiments like
this requires some hefty ballast. For those that have not been
following this for over half a year, I will restate.

A "pole pig" is one of those electric utility cans that sit on
power poles. They are properly called power distribution
transformers. On power poles they are typically used to step a
high voltage line down for residential/commercial use. For use as
high voltage power supplies they are be reversed. The cores on
these type xfmrs are "shell" wound. They do not saturate, and
they will dim an entire neighborhood unless they are externally
current limited.

I have used an arc welder in series with one leg of the 240 volt
input on the xfmrs (when run for HV supplies) to limit current.
In this use, the shunted core of the arc welder performs the
function of a variable inductance which limits the current. The
problem is that the large core of the arc welder must energize,
and the control variacs must energize, before the shell wound
core of the pig becomes energized. We are talking a few hundred
pounds of iron core and copper wire here. The resulting inductive
delay is real, and it takes a second or two for the current flow
to stabilize through the control circuits. This may not seem like
a problem, but it is like driving a strange car with gross
oversteer. Learning to handle the controls smoothly can be a bit
nerve wracking at first.

Another common method used to current limit pole pigs is resis-
tive ballast. Paralleled high load resistance is added and
subtracted to one or both legs of the low voltage supply. Oven
elements, electric heaters, bulbs, and even containers of water
doped with a couple teaspoons of baking soda, have been used for
resistive ballast. The problem with these are two fold; things
get very hot in a hurry (which is really no problem in winter,
but in a garage in August...), and there is a greater voltage
drop across the primary in the pig than is typical of purely
inductive ballast. The advantage: the power supply limited with
resistive ballast is smooth as silk; no inductive delay, the
power comes up surely and slowly, no tugging on the variacs, and
no sparking on the variac brushes.

In practice, I have found that the best techinque is to split the
ballasting up, using both resistive and inductive ballast in
series. This gives the best of both worlds.

DH> The work on the controller is going well - I have not hooked
DH> it up to the variacs yet - it's still at the store but it
DH> works well. Anyway, I will keep you posted

Sounds great!
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Date: 06-30-94 16:18
From: Richard Quick
To: Michaelj Scott
Subj: TESLA COILS, VIDEO
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RQ>Thanks for the nice letter. Your video tape was posted this
RQ>morning,you should receive it shortly after you get this post.

MS> I've only had time to watch it once,...
MS> the video does a great job of getting the thrill of
MS> seeing a monster Tesla coil venting angrily at the
MS> world. The sound effects were something of a surprise. We
MS> loved watching the experiments progress... lets us get a
MS> sense of the enormity of the project and the attention to
MS> detail.

MS> As I mentioned, I'll likely not be building a
MS> Tesla coil, but the pictures to go along with this lively
MS> reading are a must have for anyone who has been following
MS> the Tesla coil threads.

>If you have any problems, questions, comments, corrections, etc

MS> As a mere electronic engineer, I don't think that I'm
MS> qualified to offer any corrections to the high powered
MS> lash-ups that you have concocted.

MS> I look forward to sharing this with my co-workers. We need
MS> to get a TV and VCR up to work, since I do not want this
MS> tape to get "borrowed" like other lost tapes.

Thank you very much for the complements. I am very glad you
enjoyed viewing my work.

MS> I was concerned that you or an onlooker might be hurt by an
MS> errant spark. Sparks as big around as a beer can...

We have an excellent safety record. Gary has been "tickled" only
once by a static charge left on a capacitor, and I have never
received even the slightest shock. I will get lots of posts from
others who have seen the video, and they will say that my first
shock at these power levels will be my last. But I am one of
those people who seem to be very poor conductors. I wire safely,
ground properly, and steer clear of the live 60 cycle.

MS> Thanks for the wonderful video tape. It's the best thing
MS> I've seen on the TV in quite a while...

Thanks again for the excellent review, and enjoy the video in the
comfort and safety of your living room. I was not kidding when I
included the disclaimer in the video offer; all of the equipment

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Date: 06-30-94 10:59
From: Don Kimberlin
To: Richard Quick
Subj: Tesla Coils
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RQ> DK> ...OK, that sounds like there is concern for somehow
RQ> DK> "shaping" the induction field around a core, rather than
RQ> DK> merely letting it assume some random proportions, and
RQ> DK> attempting to couple to it. Or am I zooming off on a
RQ> DK> tangent?

RQ>No your shooting dead bullseyes. Field shaping is done
RQ>primarily by altering the coil geometries. Both primary and
RQ>secondary coils are juggled until good inductive coupling is
RQ>secured. The formation of a small compact field; even in
RQ>intensity and sweeping the secondary winding from the bottom
RQ>turn to the top; usually allows the most efficient transfer of
RQ>energy between two coils.

...Sure sounds like being concerned with the shape of the field
being coupled to this Dumb Old Country Boy...

RQ>... Then talking about... DK> ... the first "radio" people..

[...]

RQ> DK> ...Now, THAT's interesting to me! So Marconi hung around
RQ> DK> Tesla, eh? All the histories I've read seem to make no
RQ> DK> mention of any connection between them.

[...]

RQ>How about US legal history. The United States Supreme Court
RQ>overturned Marconi & Co. radio patents in 1943 after testimony
RQ>and US Patent Office records showed clear priorities. It was
RQ>proven that Marconi had had access to Tesla's early work and
RQ>then went on to commercialization with that information.

...I recall Marconi claiming a "breakthrough" in his placing of a
resonant circuit in the antenna. Thanks for opening up how
Tesla really showed that to him...

RQ>... talking about grounds as a... DK> ...low-reactance
DK> interface to earth.

RQ> RQ>Tesla was the first to apply ground to a tuned circuit...

[...]

RQ> DK> <the> concept that the earth does not have unlimited
RQ> DK> ability to conduct electricity away from a point contact.
RQ> DK> Oh, electric power engineers know this, but the general
RQ> DK> public..

RQ>What about earth resonate (electrically conducted)
RQ>frequencies?

...Does this get off into the area of Tesla determining the
resonant frequencies of the planet? Does the 50/60 Hertz power
frequencies figure into this? I mean, since a wavelength at
50/60 Hertz is thousands of miles, it seems one could perhaps
determine such existed...and then, I guess, from what you are
saying, treat it as a huge "tuned tank." The mind boggles at
what might happen if Man could induce enough in there to make
significant circulating currents happen...visions of melting
iron ore veins and such...volcanoes erupting and all at the utter
extreme...

RQ>... talking about Tesla's extra coil...

RQ> RQ>The third coil is not inductively coupled to the primary/
RQ> RQ>secondary...<it is an> uncoupled resonator which is base
RQ> RQ>fed by transmission line....<it> is allowed to resonate
RQ> RQ>freely, unrestricted by the inductive coupling between
RQ> RQ>primary and secondary... I believe three coil designs are
RQ> RQ>possible that are as high as 95% efficient.

RQ> DK> ...Sure seems like that would have an effective use in
RQ> DK> radio transmitters. Ever hear of anyone doing it there?
RQ> DK> They do work to achieve the highest energy transfer, but
RQ> DK> to my experience, only with a single primary and
RQ> DK> secondary....

RQ>You would have to talk to a radio engineer, but the principal
RQ>of resonance was discovered by Tesla. Tesla believed that
RQ>large resonate transformers offered the key to worldwide
RQ>xmission of commercial scale electrical power without wires.

...Well, power distribution transformers are, to my experience,
"tuned" a bit to 50/60 Hertz - at least large ones. We once had
to use one for the modulation transformer in an AM broadcast
transmitter, and its resonant peak at 60 Hertz caused us fits
till we shaped the audio passband coming in to attenuate the
daylights out of stuff below 100 Hertz...

RQ>If you electrically examine the system output, the secondary
RQ>(or "driver") coil in the three coil magnifier is simply the
RQ>secondary on a resonate transformer. The extra coil and earth
RQ>(the top and bottom connections to the secondary driver coil)
RQ>are acting as end resonators. Tesla to his patent attorneys
RQ>clearly stated he had discovered, and operated his equipment
RQ>modulated to, earth resonate frequencies below 30,000 Hz.

...Again, appears he determined some fundamental resonant
frequency of the globe, and its harmonics...

RQ>Looking at the oscillator as a whole, the current flow from
RQ>the air terminal was small. Tesla operated at very high
RQ>voltage, but retarded spark breakout when working with CW
RQ>xmitters. The system is very easily converted to spark
RQ>production, as witnessed by the publicity spark photos Tesla
RQ>took of the Colorado Springs Machine.

...Heheheh....He sure was into Extra High Voltage, I guess. Now,
a century later, we have people arguing deeply about the static
fields around those, too. Could be scary. I note some claims
that the right-of-way under those seems to not have land clearing
problems with brush growing back, and that there are standards
for farmers keeping cattle from grazing beneath them...something
about souring milk and such. Don't know how much reality there
is to all that.... (704)792-9241 (1:379/37)

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Date: 07-01-94
From: Michaelj Scott
To: Richard Quick
Subj: TESLA COILS, VIDEO
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RQ>Thanks for the nice letter. Your video tape was posted this
RQ>morning, you should receive it shortly after you get this
RQ>post. I included a disk with many related text files. It
RQ>should make for some interesting reading, as the archived
RQ>material goes back over six months.

Richard, I still haven't looked at the disk, but the tape has
been seen by most of the engineers in the office. One who saw it
dropped a brochure on my desk today for an auction Jul 14 in
Dunkirk, NY. It seems that Ferranti Packard ( a RollsRoyce
transformer company ) is being liquidated by Corporate Assets Inc
(416) 962-9600 in Canada.

What struck my eye was a setup with two Tesla coils with toroid
top hats. This setup is called a Hipotronics model DIMS-5D
B.I.L. tester consisting of impulse generator, 6 capacitors, 6
sets of spheres, 2 voltage divider stands, a computerized control
station, and several spares that was all new in 1991. Also shown
is a corona tester, a noise meter, FP spark gap station with
adjustable 25 cm spheres, FP Transformer test system, 500 KVA
with built-in 80Kv hipot coil which is supplied by Canron 500KVA
150kw motor generator or Superior Electric 190 KVA power stat.

The Tesla coils are a matched pair and appear to be too tall
(over 6 feet) to roll through a door. The Toroids appear to be 2
feet in diameter. The pictures show 6 inch copper braiding
connecting everything together. The spark gap station has two
electrodes ala stalctites and stalagmites with a gap of about 2
feet. Everything is extremely heavy duty on casters. The
pictures show the control station in a separate room where it
might be a bit safer.

There are 9 pages of color photographs of low frequency coil
winders, oil & silicon processing plants, ovens, pumps, machine
shop stuff, and tons of copper & aluminum inventory. Delrin
tubing, radiators, lightning arrestors, wire bushings, solenoids,
contactors, and finished products from Ferranti-Packard like a
3600KVA auto transformer and a 1000 KVA 23695Y/216Y/125W.

I'll make a copy and send you the original. It would make a
great video. If this stuff has more than scrap value, it would
be a shame to see it melted down before a hobbyist got a chance
at it. Maybe some of the Tesla society people in the Buffalo
area should be advised of the auction.

(916) 448-2483 (1:203/52)
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Date: 07-01-94 09:42
From: Mike Procospo
To: All
Subj: Telsa Coils
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I'm interested in making a telsa coil for a little experiment of
mine, could any of you write to me with some information on how I
would go about doing this? Thankz a lot (407)323-0025 (1:363/77)

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Date: 06-28-94 21:44
From: Roy J. Tellason
To: Roger Ream
Subj: Tesla Coils
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24 Jun 94, Roger Ream writes to Roy J. Tellason:

RR> Actually, the article in Popular Electronics (and yes, it
RR> was the mid-sixties, and I may be able to dig it up, if my
RR> dad hasn't gotten rid of them)

'64 or '65 feel about right, though I really couldn't say for
sure.

RR> was part of a two-parter, although PE didn't know it at the
RR> time. The article concerning the "standard" tesla coil
RR> spawned a tube-excited version called the "Li'l TC."

I remember that one a little bit, used a horizontal output tube
of some sort, didn't it?

RR> I'll have to ask my dad if he still has the old box of PE,
RR> next time I'm at the ol' homestead<g>!

I'll be looking forward to whatever you may find out.
TANSTAAFL BBS (1:270/615)

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Date: 07-04-94 14:43
From: Richard Quick
To: Mike Procospo
Subj: Tesla Coil,cap,1/2
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The High Voltage, Pulse Discharge
CAPACITOR

Many high voltage projects require high voltage pulse discharge
capacitors (cap). Whether your project is a rail gun, Tesla coil,
or particle accelerator, maybe even a pulse laser or high powered
taser, you will need some high voltage rated pulse discharging
capacitor in your device somewhere. Plastic film caps are best.

Commercial units are expensive. Manufacturers of these units do
not stock them typically, every unit is built to order. Off the
shelf caps (mica, vacuum, titonates) do not offer the performance
required for many high voltage projects. Off the shelf capacitors
get hot, have high loss to output ratios, and will break down in
spark excited or high current tank circuits. Some types are a
potential explosion hazard.

You can build your own "plastic film" type capacitors for these
projects from polyethylene plastic and aluminum flashing.

The following instructions are for a pulse discharging capacitor
with a .02 uf at 35-40 kvdc rating. The unit is rated for work in
spark excited tank circuits with up to 15 kv rms inputs, 12 kv is
the recommended maximum rms AC voltage rating; but these caps
will fire all day at 10 kvac without getting warm. This is an
ideal unit for small to medium Tesla coils. The material cost is
around $100.00 per unit as opposed to $200 - $250 for a custom
commercial capacitor with this rating.

Materials for this unit are as follows:

Three yards of low density, 60 mil, polyethylene plastic. This
plastic is available from any good sized plastics dealer. Dielec-
tric constant between 2 and 2.2 (figure 2.0 in homemade caps).
Dielectric strength is 1000 VDC per mil. (thousandth inch, USA)

One ten inch by twelve inch sheet of 1/4" plexiglas.

One fifty foot roll of 14 inch wide aluminum flashing. This will
make 4.5 capacitors. Hardware store.

Eighteen inches of 1 inch schedule 40 pvc pipe (thick wall).
Plumbing supply

Two: end caps for the 1 inch schedule 40 pvc pipe. The end caps
must have flat bottoms (not rounded) or you will need to cut
or flatten them. Plumbing Supply

Twenty inches of CLEAN, 6 inch PVC DRAIN PIPE. DO NOT USE
SCHEDULE 40! Six inch pvc, thin wall, DRAIN PIPE is available at
any good plumbing supply in ten foot lengths.

One: six inch pvc DRAIN PIPE END CAP. Plumbing supply

One gallon of pure U.S.P. Mineral Oil. Drug Store

Misc, items.

Two: 1/4 x 20 brass machine screws and four nuts.

Two: #8 Pan Head Machine screws with washers and nuts. Screws
should be about 3/8ths of an inch or less long.

Loctite thread fastener (medium strength)

Six or eight: 12" long nylon wire ties

PVC cement (medium body, clear, works best)

PrepSol (Dupont paint store) or U.S.P. alcohol

Four inch stack of clean newspaper or BUTCHERS PAPER

Lint free wipes or good quality paper towels. Don't use the cheap
stuff.
-----------------------------------------------------------------
BUILDING THE CAPACITOR TANK

Start out by cutting the PVC drain cap in half. You want to cut a
ring 1-1/2" high off the end cap. The bottom of the end cap
should be saved intact with a 1-1/2" high side wall.

Lay the ring cut from the 6" PVC drain cap on the sheet of 1/4"
plexi and scribe a circle. Cut the circle out and glue it to the
ring with PVC cement. This forms the clear, see through, lid for
the capacitor tank. When the PVC cement has dried, drill two
holes through the plexi for terminals. The holes should be on
opposite sides of the lid. A small hole is drilled dead center
for venting.

Cut some strips of plexiglas, 3/4" wide by 2" long, out of the
scrap material.

Glue one of the 1" PVC end caps to the center (inside) of the 6"
PVC drain cap. Glue at least four of the plexiglas strips around
the 1" end cap. The strips are placed so that they are flush with
the 1" PVC end cap. They should form a "star" pattern radiating
out from the center and form a shelf, 3/4" high, for the
capacitor roll to sit on. This shelf prevents the roll from
resting on the very bottom of the tank and allows oil to
circulate. It is important that there is sufficient room between
the edges of the shelf and the side wall of the 6" drain cap to
allow the 20" section of 6" PVC drain pipe to seat all the way to
the bottom of the end cap.

When the end cap assembly is dried, glue and seat the 6" PVC
drain pipe in place. Use plenty of PVC cement to prevent leaks.

Once the end cap is firmly seated in the 6" PVC pipe, then cement
the 18" length of 1" PVC pipe down into the center ring. This
pipe saves oil, as well as providing a center post for the
capacitor roll. Glue the second 1" PVC end cap onto the top of
the 1" pipe to seal it.

Let the entire assembly dry thoroughly. Clean the tank out well.
And this completes the capacitor tank construction.

THE CAPACITOR ROLL

The capacitor roll is made from the polyethylene sheet and the
aluminum flashing. It is important that these materials are
absolutely clean and free from defects.

Vacuum up a work area large enough to lay all of your plates and
dielectric out. If things are dusty you may want to mop. When the
work area is clean, lay down fresh newspaper, or even better,
butcher paper, over the entire work area. You will need a long,
hard, smooth, flat surface to roll your capacitor up on.
A clean, paper covered, concrete floor works well, as does a
couple of paper covered buffet tables.

Cut the poly sheet lengthwise into three equal strips. The
standard material width for this sheet is 48 inches. You will get
three 16" wide strips from the sheet, though only two strips will
be required to make one capacitor roll. The strips must be washed
and wiped on both sides with PrepSol or alcohol and lint free
wipes or high quality paper towels. Then they must be wiped dry.
Static may become a problem here, and the dielectric may collect
dust. A ground strap run to a water pipe may be wired to a copper
or brass brush. The plates and dielectric may be swiped lightly
to ground out static, but do not scratch the material.

Cut two lengths of aluminum flashing 102" long. The flashing must
be six inches shorter than the polyethylene strips. The material
is already two inches narrower. Use a good pair of heavy duty
scissors to cut the aluminum. The strips of flashing (plates)
must have the corners well rounded, and have all sharp edges
smoothed. Trim the corners off with the scissors, then sand all
edges you cut it #150 emery cloth. Drill a hole, 1/2" from one
end of each flashing strip for the terminal mount. Inspect your
plate. It should have no dents, sharp points, "ruffles" along the
edges, etc. Many flaws can be carefully worked out.

The aluminum capacitor plates must be washed and dried. Fill a
five gallon bucket with very hot water and a good squirt of
liquid detergent. Roll the plate up and "dip, swish, and swirl"
until all the sanding grit, manufacturing oil, and dirt wash off.
Rinse the plate well and stand it on its edges on clean newspaper
until it is dried. Don't worry if the plates oxidize a little.

Lay out your meticulously clean plates and dielectric sheets.

Lay one strip of plastic dielectric down first. Then lay a plate
on top and center it. The plate is centered so that there is a
one inch border of dielectric plastic evenly along the long
sides. Line up the end of the plate with the terminal hole flush
(even) with one END of the plastic. The far end of the plate will
be six inches short of flush with the bottom dielectric sheet.

Lay a second sheet of plastic on top so that it is exactly lined
up the bottom strip of plastic.

Lay the last plate down on the stack and center it. The plate is
centered so that there is a one inch border of dielectric plastic
evenly on both of the long sides. Now, the first plate you laid
will have the terminal end flush with one end of the bottom
dielectric, it makes no difference which end; line up the second
plate so that the terminal end is flush with the end of the
second dielectric sheet, but it must be at the opposite end from
the bottom plate terminal.

Cut two 1" strips of aluminum flashing 14" long. Tape them
together into a 1" strap. Round it and sand it. Then untape it
and wipe or wash the strips. Reassemble and punch a hole in each
end. One hole for a 1/4" or larger screw (tank terminal), the
other for the #8 pan head machine screw (plate terminal). Using a
#8 pan head machine screw, mount this strap into the terminal
hole on the top plate. Use a flat washer, a tiny drop of loctite
thread fastener, and then a nut. Snug the connection down firmly.

This strap serves as a high current lead from the plate to the
terminal mount on the capacitor lid. Make sure that it is the
smooth pan head of the screw pressing into the plastic capacitor
dielectric as the capacitor is rolled up; not the sharp screw
shaft. Do not allow the sharp threaded end to press into the
capacitor. It is a good idea to have a couple of spare patches of
60 or 30 mil plastic to place under the pressure points of the
terminal connector screws. This will help prevent breakdown.

Starting from the terminal end of the top plate on the stack, the
end with the terminal strap already mounted, roll the capacitor
up as tightly as possible. Make sure that the top plate does not
curl around to touch back on itself on the first turn. A strip of
extra plastic here can be helpful. If the first turn of the roll
looks poor, then unroll, line everything up, and try again.

When the capacitor is tightly rolled, do not loosen your grip.
Have an assistant put two wire ties together and slip them over
the roll. When the wire ties are cinched, you may loosen up.

As you rolled the capacitor up, the first plate in the stack
worked its way out of the roll a few inches. This plate should
present you with a terminal hole to mount a second 1x14" strap of
aluminum for the second lead.

Mount the second lead, making sure the smooth screw head is
against the capacitor, not the sharp threaded end. You will have
one lead coming up from inside the roll, and the other coming up
from the outside. Put at least three wire tie strips around the
roll. Two 12" wire ties connected together will give enough
circumference.

Set the capacitor roll into the tank. Fill with one gallon of
mineral oil. The roll must be covered by at least a quarter inch
of oil to suppress corona and prevent flashover. Note that the
oil soaks into the roll. The level will drop after filling, and
may drop again after use. Check on it occasionally until the
capacitor is fully broken in, a period of about six months.

Connect the leads from the capacitor roll to the tank lid. For
the tank lid terminals use at least 1/4 inch brass machine screws
and tighten down well. The head of the machine screw should be
inside the lid, the first nut on top will hold the connection
tight, the second nut is removable for connection to your
circuit. Do not seal or glue the lid in place.

Do not apply the full rated voltage to these units until they
have set for at least three days, and the oil has had a chance to
soak in to the roll. It is best to start them out at about half
voltage, or less, and run them for short periods for the first
few days on a smaller coil. These units run on the ragged edge of
their voltage ratings, yet they are quite serviceable. On larger
coils it is best to put these units in series/parallel to back
them up against kickback.

Because the material width of the polyethylene is 48", you get
three 16" strips of dielectric from cutting a length. You will
have one strip left over. Because of this, it is perhaps better
to plan on building at least two units at a time. This makes more
efficient use of material, but more so for the use of time. Once
a temporary "clean room" has been established it makes sense to
use it to fullest advantage.

When coiling in general it is best to "back up" this capacitance
by placing two tanks in series and then placing two series sets
in parallel. Thus you need four tanks to equal the value of one
tank alone, but the four tanks will withstand twice the voltage.
You will find it more economical to build three extra tanks, and
run them in series/parallel, than building one tank and having to
repair or replace it if it fails before it completes the long 6
month full break in period. Later you can risk the option of
running them at their full rated voltage, should you choose, or
increase power by playing it safe and building more caps.

The effort in building a first class cap is worth the extra time
and expense to do it right. The unit will last longer, withstand
more abuse, and give you more capacitance if it is well
constructed. Once this effort is expended, and the unit is in
service, don't blow it. Rather than risk the investment you
should build more caps, "backing up" your existing caps and
increasing power with additional caps as you go. Don't overdrive
these, you will blow them.
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Date: 07-04-94 14:00
From: Richard Quick
To: Mike Procospo
Subj: Tesla Coil,xfmr,1/2
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
> From archives
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 11-05-93
From: Richard Quick
To: All
Subj: 10KVA Tesla Coil
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
If you are interested in making a high voltage, high current,
power supply, I can tell you how to do it for free....

First call the local neon shop(s) and tell them that your working
with Tesla coils. Ask them to hold all of their failed xfrmrs so
you can pick them up. Make sure you talk to the boss or foreman,
and tell them that you want dead units. I have never had a shop
turn me down for free cores. They are happy to get rid of them.

There are two types of failed neon xfrmrs: warranty units, and
old junk. The local shop must return units that fail within the
two year warranty period back to the distributor for credit. Old
junk (older than two years) you can pick up for free right from
the local shop, but I also scavenge from the distributor. Ask
where the failed warranty units go.

If you can locate the distributor who sells wholesale, and
handles failed warranty units, you have found a gold mine of high
voltage xfrmrs. The distributor removes the PLATE from the xfrmr
for return to the manufacturer, and throws the unit away. The
manufacturer credits the distributor for the plate, as the
shipping is too expensive. The cores go to the dumpster.

After locating your source of failed units, be selective. Try to
bring home the high current units. Ratings commonly used are 9
kv, 12 kv, & 15 kv, with common current ratings of 30 & 60 ma.
Once in awhile you will come across a 120 ma unit. I grab all
of the high current units (60 ma+) I can get in these voltages.

First test your units. Use wire with a 15 kv rating or better.
This wire can be obtained where you pick up the transformers.
If you ask they will usually cut you off a few feet for free.
I prefer using the solid polyethylene core from RG-213 coax, as
it will withstand the voltage with gobs of extra safety margin.
Draw an arc from the HV bushing to the case, one at a time.

About 50% of the "failed" units I pick up are just fine and need
nothing other than a clean up. There is nothing wrong with them.
Often shops get these units from signs they have dismantled, and
they just toss them into the junk pile with the rest. The other
50% are bad. Either one, or both, of the HV windings have broken
down. These units can frequently be repaired.

Remove all hardware, and insulators if possible. Take a hammer
and a chisel and remove the cases by splitting them down the
corners. Break off any stubborn insulators, but preserve
the lead wires. You are left with a block of tar. Set the unit
outside when it is very cold, or place in a freezer, and let it
freeze solid overnite. The next morning, short the high voltage
lead wires (you preserved them!)with a clip lead, and connect 110
volts across the primary. Since the cores on these transformers
are shunted, they may be shorted without harm or blowing fuses.
Let the unit cook for 15-30 minutes (varies with size & temp).

Disconnect your leads, and with the chisel and hammer, chip a
groove around the block. You want to score a groove lengthwise
that will allow the block to cleave in two. Then, starting from
one end of the block, chip until you hit the core, then do the
same with the other end. Pry and chip the tar away from the core
until the xfrmr is free. The core may then be disassembled, and
the windings removed and examined. Kerosene and a stiff brush
will clean up the windings and core of any remaining tar.

The "cold-cook" method is fast and it works well. Frozen tar
chips away cleanly. The "cooking" warms the core, softening
the tar, and allowing it to release. The only other ways I know
to free the cores are long soaks in solvent such as kero or gas,
(the nasty waste does make a good tar crack filler), or melting
out the tar with external heat from a fire or oven.

Most units fail when the high voltage breaks down the tar insul-
ation. The resulting carbon track shorts the winding. Simply
removing the tar brings them back to life. Other times the coils
break down internally. In this case I discard the winding after
disassembling the core, and replace it with a good winding from
another unit of the same model with the same type failure.

While the core is apart, you can beef up the current output by
removing a few of the shunting plates between the windings. Never
take out more than 2 or 3 of these plates per side, as the
additional power output will burn out the secondaries. Generally
I get about 70-75 ma out of 60 ma units after I have finished.

Rebuilt units need a little protection from the high voltage
secondary outputs. The first thing I do is solder on a new lead
wire to the high voltage windings. The HV secondaries are wound
with very fine magnet wire, in the 30 ma units the wire is not
much thicker than a coarse hair. Once a good solder connection
is made, bed the connection and the first 1/2 inch or so of lead
wire to the top of the HV winding with hot glue or clear epoxy.
The lead wire need not be anything special, any thin insulated
stranded wire may be used. Heavy wire increases the chances of a
failed connection due to mechanical stress. When setting the unit
up to fire you simply have to route it on insulators.

The windings themselves are wedged against the core to prevent
vibration. I have seen wood, bakelite, and plastic wedges used
commercially. What I like to do is to soften up some 30 mil
polyethylene plastic sheet in boiling water, and heat the core in
a warm oven. I wrap dry softened plastic around the core and
gently force the windings down on it. Once cooled, the windings
have some insulation from the core, and they will not vibrate.

The base wire from the HV windings must be grounded to the core.
Use the original grounding point if possible, if not you may
split the core apart slightly with a thin blade and insert the
wire into the gap before you clamp the core back up. If required
you may splice on a small piece of wire for added length.

Neon sign transformers that have been rebuilt may be fired dry.
The tar used to pot the cores for neon use does not really
insulate well against the RF and kickback from the Tesla Tank.
The units last longer when they are freed of the tar potting. The
only other choice is to sink rebuilt units in mineral or xfrmr
oil which is a very good RF insulator. I choose to fire them
"dry"; it works, and there is no mess.

Neons may be run in parallel to deliver the current required to
fire medium sized coils, and I have run up to 4000 watts with
banked neon power supplies. The general practice is to run these
banks off of 240 volt feeds controlled through a variac. Neons
with matched outputs are run in pairs in these banks. The
primaries are paired up in series, and the secondaries are all
paralleled to the HV buss. Phasing is important here, and each
transformer must be checked as it is added to the bank to ensure
it is in phase with the other units. If an xfrmr draws an arc
from a lead wire brought to the HV buss, the primary or secondary
connections must be reversed.

Neons typically have an efficiency of about 50%, in that they
draw twice as much power as they put out. This problem can be
resolved with the use of power factor correction (pfc) capaci-
tance across the line. The pfc capacitors used are the same as
for alternating current motors. The voltage rating should be at
least twice the line current used, and I like a 4x voltage margin
for long life. The formula used to determine ballpark pfc is as
follows:
9
10^
C = Corrected kVA ------ 2
2(pi)f e^

This should read C = Corrected kVA times (10 to the ninth power)
over, (2 pi times f times e squared)

C = required capacitance in microfarads
f = frequency of applied voltage
e = applied voltage

Corrected kVA is determined by dividing the volt*amps (watts)
output of the neon sign xfrmr by 1000

Using a pair of rebuilt 12 kv, 60 ma neons, with 2 shunting
plates removed from the core next to each HV winding, and power
factor correction capacitance, you can get a nice 1.5 KVA Tesla
power supply with over 90% efficiency. Total cost: $5.00 for the
pfc capacitors, and a few hours of time.

I have unpotted dozens of neon transformers from many different
manufacturers. I have tried to make this as informative as
possible, and have checked it over for mistakes. If I have erred,
or was not clear on something, please let me know. Use common
sense, and don't expect the first attempt to work out. On my
first attempt I managed to destroy a HV winding during the
unpotting, as I did not know where the windings were located on
the core. But once you see one core unpotted, with minor
differences, you have seen them all.
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Date: 07-01-94 23:01
From: Richard Quick
To: Don Kimberlin
Subj: Tesla Coils
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
We were talking about the conductivity of earth grounds...

RQ>What about earth resonate (electrically conducted)
RQ>frequencies?

DK> ...Does this get off into the area of Tesla determining the
DK> resonant frequencies of the planet? Does the 50/60 Hertz
DK power frequencies figure into this?

Yes. No. Tesla determined that we would run on 60 cycle for a
couple of unrelated reasons. He had a quirk about doing a lot of
things in multiples of three. He ran three phases in his 60 cycle
work, but he also liked the motor design that 60 cycle offered.

DK> I mean, since a wavelength at 50/60 Hertz is thousands of
DK> miles, it seems one could perhaps determine such existed ...
DK> and then, I guess, from what you are saying, treat it as a
DK> huge "tuned tank."

Well I did attend a lecture by two EEs working at NASA who did
some "listening" with highly specialized equipment. They would
set up heavy earth ground points and listen with amplifiers.
Everywhere they went they heard 60 cycle at about the same
intensity, so the US in any case does appear to be impressed with
60 cycle from our power grid. But 60 cycle is not a frequency
that naturally resonates the earth.

DK> The mind boggles at what might happen if Man could induce
DK> enough in there to make significant circulating currents
DK> happen...visions of melting iron ore veins and such...
DK> volcanoes erupting and all at the utter extreme...

There would be no "induction", "circulating currents" or
disturbances. Tesla saw the earth as a giant resonator when
electricity at the properly tuned frequencies was conducted into
it. As a conductor floating in space it is nearly perfectly
insulated, so it would be very low loss. Electrical energy
conducted through the crust (not induced) would remain as a
resonate standing wave (as opposed to a circulating current).

Funny thing today however. My brother was telling me his vision
of the same thing: earthquakes, tidal waves, volcanos. But he was
confusing mechanical resonance with electrical resonance. Tesla
was an expert with both, and once stated that given enough TNT it
was possible to cause major fractures in the earth's crust by
timing a series of detonations. The detonations he said, would
have to be timed to induce a moving resonant wave, and the
amplitude of the wave would have to be developed over a period of
several months.

But back to the wireless power transmission using cavity resonate
properties of the earth. The way I see Magnifing Transmitter is
more like a pump. The high voltage field maintained on the smooth
toroid (air terminal) forces energy into the ground.

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Date: 07-02-94 00:12
From: Richard Quick
To: Don Kimberlin
Subj: Tesla Coils
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Oh, BTW

You were talking about shaped fields. You asked if the Tesla coil
employed aspects of a shaped shield, then you said...

DK> Or am I zooming off on a tangent?

then I replied...

RQ>No your shooting dead bullseyes.

Then I described how the fields are shaped. You followed that
with...

DK> ...Sure sounds like being concerned with the shape of the
DK> field being coupled to this Dumb Old Country Boy...

No your not dumb at all. We are in complete agreement and I am
very concerned with the shape of the field being coupled.

"Shooting dead bullseyes" was meant to imply that your thought
process had progressed forward quite logically after intial
acceleration and that you had arrived at a conclusion that was
correct and important to efficient design parameters. You also
made it seem easy.
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Date: 07-04-94 01:24
From: Richard Quick
To: Mike Procospo
Subj: Tesla Coils
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
><Imported from Archives, 11/10/93 to DH & 10/10/93 to DB

DB> How did you go about winding your coil? What are the specs?

The first step in winding a coil is to select a coil form. The
coil form should be a low loss material (we are talking RF
losses) like polyethylene, polystyrene, or polypropylene: but the
most common material is PVC plastic drain pipe (thinnest wall is
best) which is high loss. I used a section of PVC thin wall flume
duct.

Ratios of coil height to width are important. Small coils (3" to
6" diam) work best with aspect ratios (height to width) around
5:1 - 4:1, larger coils (8"+ dia) have aspect ratios around 3:1.
Now we are talking about the actual winding length here, so allow
an extra inch or so of coil form on each end. Determine the
length required and cut the ends square.

The form must be sanded smooth of surface imperfections, dried
thoroughly, and if PVC is used, it must be sealed. A good sealer
is polyurethane, another is two part epoxy paint. By sealing the
surface of the PVC before you wind on wire you can negate the
excessive losses in PVC plastic coil forms. If necessary the coil
form may be sanded again after the sealer had dried.

The coil should be wound with good quality magnet wire. I use
double Formvar enamel coated magnet wire. Magnet wire gives you
maximum inductance. A coil should have over 900 turns, but not
too much over 1000 turns. There is a little leeway here. Select a
gauge of wire which will allow the aspect ratio and number of
turns to fall within this range.

I dug that up as it pretty much explains things, and you may have
missed the post.

DH> What determines a certain plastics being good?

The dielectric constant is not the factor to go by when choosing
a coil form. It is really preferable to use a plastic with the
lowest dielectric constant. The reason for this is you want the
distributed capacity of the coil to be as low as possible.
Capacitance in a coil reduces throughput, and we want the
throughput to be as rapid and efficient as possible. The
distributed capacitance in a coil retards the current peak
that follows the VSWR (resonate rise). Coils have enough problems
with distributed capacity from the length of wire, the closeness
of turns, and the number of windings. No need to make things
worse by choosing a plastic with a high dielectric constant.

What is most important in choosing a coil form material is the
dissipation factor. The dissipation factor of all commercial
plastics has been calculated, and somewhere in this mess I have
those figures. If my memory serves me correctly, the standard
RF dissipation factors are based on a frequency of 1 Mhz, close
enough to judge if the plastic is suitable for coil work.

The next important factor to look at is the dielectric strength.
This should take second place to dissipation factors if your goal
is to build the most efficient coil possible. Proper con-
struction, more than anything, prevents electrical breakdown.

Even if the dissipation factor is very low (good efficiency) it
is best to use the thinnest wall coil form possible. Turns of
wire, coats of sealer, and hard plastic end caps will stiffen the
coil some. Low density polyethylene forms (such as wastebaskets)
give coils with very high "Q" factors (a measure of efficiency)
but are difficult to work with, as this plastic is very flexible.

As far as the electrical strength of a coil wound on a very thin
walled plastic tube, it should not break down internally if THE
WIRE IS NEVER ALLOWED INSIDE THE COIL FORM. Do not drill holes
or introduce the wire into the side of the coil. A hole anywhere
on the coil sidewall will cause a failure regardless of the di-
electric strength of the coil form plastic. My coils are capped
top and bottom with plexiglass plates that are approximately the
same thickness as the coil form wall. I use two-part epoxy cement
and I seal them airtight. It is OK to drill one small hole in the
bottom plexiglas plate to equalize air pressure, but I do not.

The air terminal capacitance (discharger toroid or sphere) is
connected by lead wire (I just use the magnet wire and avoid
splicing) from the top of the coil. The lead wire is "air wound"
up to the terminal, with the turns about the same diameter as the
coil, or a little smaller. You will see me doing this in the
video when I set up for a low power test in the garage.

The terminal capacitance must have a diameter greater than the
coil form, or spark will break out; either from the top of coil,
or from the air wound turns connecting the coil to the terminal.

The other construction secret not covered in the video is the
ground connection. Once the coil is wound and sealed I take the
base wire and pull it up out of the sealant until it is free all
the way to the beginning of the first turn. I clip off the excess
wire, leaving about a 2" tail. I lay the tail on a metal block,
and using a small ballpeen hammer, flatten it out as best I can.
A strip of copper sheet about 3/4" by 2" is then cut from stock
and bent slightly to match the curvature of the coil form. Solder
the flattened tail to the back of the copper strip. Position the
strip on the coil form just below the bottom turn of wire, and
scribe a rectangle through the sealant all the way to the coil
form plastic. Remove the sealer from the scribed area, then score
and clean the bared plastic. I then use epoxy to bed the copper
strip. This forms a high current grounding plate without
drilling. Ground wire or strap (preferred) can be held in firm
connection to the plate with tape or a large rubber band.
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Date: 07-01-94 23:53
From: Richard Quick
To: Michaelj Scott
Subj: TESLA COILS, VIDEO
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
MS> It seems that Ferranti Packard ( a RollsRoyce transformer
MS> company ) is being liquidated by Corporate Assets Inc (416)
MS> 962-9600 in Canada.

I edited a little here, but you have a photo brochure...

MS> What struck my eye was a setup with two Tesla coils with
MS> toroid top hats... impulse generator, 6 capacitors, 6 sets
MS> of spheres, 2 voltage divider stands, a computerized control
MS> station, and several spares that was all new in 1991. Also
MS> shown is a corona tester, a noise meter, FP spark gap
MS> station with adjustable 25 cm spheres, FP Transformer test
MS> system, 500 KVA with built-in 80Kv hipot coil which is
MS> supplied by Canron 500KVA 150kw motor generator or Superior
MS> Electric 190 KVA power stat.

This type stuff is used to test the breakdown voltages of various
power utility designs and equipment. There is an obvious need to
test aspects of commercial power transmission systems before
putting them into service. Testing includes lightning strikes,
insulation breakdowns, power arcs, corona leakage, etc.

That Superior Electric 190 KVA powerstat (variac) would be some-
thing to cry over if it ends up sawed into pieces for scrap
copper. This is HEAVY commercial grade equipment (think of the
inductive delay as those variacs energized) that frequently goes
by the pound...

MS> There are 9 pages of color photographs of low frequency coil
MS> winders, oil & silicon processing plants, ovens, pumps,
MS> machine shop stuff, and tons of copper & aluminum inventory.
MS> Delrin tubing, radiators, lightning arrestors, wire
MS> bushings, solenoids, contactors, and finished products from
MS> Ferranti-Packard like a 3600KVA auto transformer and a 1000
MS> KVA 23695Y/216Y/125W.

Oh, for about $30,000 and a place to play with it all!

MS> I'll make a copy and send you the original. It would make a
MS> great video. If this stuff has more than scrap value, it
MS> would be a shame to see it melted down before a hobbyist got
MS> a chance at it. Maybe some of the Tesla society people in
MS> the Buffalo area should be advised of the auction.

I will do what I can to pass it along. One problem with this
stuff... You can snap it up at bargain basement prices, for they
do sell it for the scrap value, but you have to haul it away.
Those Superior Electric powerstats I am drooling over; I know
just enough about these puppies to know that a 190 KVA stack
weighs in over 1200 pounds (545 kg), and would not be surprised
to see it come in at one US Ton. The new stack ran many thousands
of dollars, yours for probably $50.00.

Money could be made if you could purchase items indivually, or
small lots, and part them out to other coilers. The same
powerstat is almost surely a motor driven gang of smaller
variacs. You could split them and give several coilers a good
jump in power levels. Similarly, die spun aluminum toroids and
spheres are a few hundred bucks apiece new. But you need a place
close to these auctions to hold the junk until it is sold and
shipped. Moving this stuff around by commercial carrier costs $$$
because we are talking heavy metal to people who are paid by the
pound. You have seen those full sized trucks that only carry one
roll of steel, or one large I-beam, or one motor-generator...

Humm, maybe I need to wait to build my lab until I find some
commercial property with a rail siding...
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Date: 07-04-94 23:08
From: Sjoerd Schaafsma
To: Richard Quick
Subj: Tesla coil Video
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Howdy Richard,
We had my parents over this weekend and I mentioned your video
to the old man. "Oh ya that sounds interesting," sez he.
After 10 minutes or so it was, "Those guys are crazy," and I'm
saying to myself "Far out!"

We got as far as the long demo with the big toroid where you
had the mini lightning storm before Pa was nodding off. I'll
have to go back and watch the techie stuff with the
explanations by myself. For the most part we fast forwarded
to the action shots. You'll get more running commentary as
we watch more of the video, and perhaps some intelligent
questions after I've read some background material. A lot of
the explanations are over my head, like a grade 3 math student
being hit with ratios and rates. I can't see asking you to
explain basics when I haven't read the files you sent on disk
yet. I'm a firm believer in RTFM.

BTW, once I have a backup copy of the video, you can be sure
it'll be making the rounds here. more later. Sjoerd Schaafsma -
An occasional 8 bit holdout [403]327-9731 Lethbridge,AB
(1:358/17)

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Date: 07-03-94 16:37
From: Brian Thurston
To: Richard Quick
Subj: TESLA
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Hi Richard:

I am not absolutely sure (grade 12 science class is a LONG time
ago) so I will not contest his (Tesla's) earthly point of
departure. By most accounts a brilliant man with limited social
graces. BC, Canada (1:153/915)

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Date: 07-04-94 16:54
From: Richard Quick
To: All
Subj: Tesla caps 1/2
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I posted a two part message to Mike the other day detailing
construction of a rolled type pulse discharge capacitor. Since
the detail of this particular unit was pretty well covered, I
will focus on other homemade types; the flat stacked plate type
capacitor, a little on the salt water cap, and a little on
capacitor theory as it applies to Tesla coils.

I have seen several types of homemade stacked plate capacitors.
The two types differ as to the orientation of the plate stacks.
Some are stacked vertically, others are stacked horizontally.
Before I go into construction details I should cover some of the
advantages of flat stacked plate caps for use in Tesla coils and
other high voltage applications.

Flat plate caps have little or no no internal inductance. Rolled
caps contain two or more plates which are spiral wound. Rolled
plates exhibit some properties of coils, and they contain a
certain degree of self inductance. This limits the size of the
rolled cap for many, including Tesla applications. As plates grow
in size, the self inductance grows, and the caps exhibit
self-resonance that will interfere destructively with the
oscillation of the Tesla tank circuit. The rolled cap that I
posted about previously, is about as large as you can get in a
single unit without having self-resonance drop below 1 megahertz.

Flat plate caps are better adapted for pulse applications. Rolled
caps have to discharge a long plate. The further away the free
end of the plate is from the high current terminal, the longer it
takes for the cap to discharge. In essence this distance is also
an extension of the tank circuit wiring, as the plate gets longer
losses increase. Again the rolled capacitor I posted previously
is pushing the design limits of efficiency in this area. As the
rolled cap gets larger, efficiency of pulsing drops off.

Flat plate caps can be constructed to handle higher voltages.
Rolled caps have efficiency limits in individual units as to the
breakdown voltage. A single dielectric is used per plate. If
dielectrics are made thicker, efficiency drops off, if made
thinner efficiency increases, but they break down. Using standard
materials, the rolled cap I posted about is at the edge of this
design limit as well.

Flat plate caps can be built for larger capacitance. The rolled
cap, because of the design constraints listed above, won't give
you much additional capacitance without increases in losses,
problems with self-resonance, and lowering of the capacitor Q.

The rolled cap that I posted is a good unit. I have built nearly
20 of these caps, and I use them a lot. But do not look to expand
much on this design. It has passed through several improvements
and I really think it is pushing the design limits in all of the
important areas. Next we need to look at the flat plate cap, as
there is much to be done yet, but first look at the dielectric.

The best Tesla capacitor dielectric is low density polyethylene
plastic. Whether you build rolled, stacked plate, or salt water
caps you should look hard at this plastic before settling on
anything else. It has an extraordinarily low RF dissipation
factor for the cost. The actual "in use" dielectric constant on
homemade caps using this plastic is right around 2. This is a
little lower than the book value (up to 2.2), but homemade
applications of this dielectric rarely have the close plate
bonding that are achieved commercially.

This dielectric melts at 100 deg. C. But because of the very low
dissipation factor the plastic is subject to very little in-
ductive heating. There is little loss, therefore little heating.
When using this plastic however, it is imperative to cover in
mineral oil to distribute any heat that is formed, suppress
corona and displace air. Plastic caps not covered in oil are
guaranteed to fail in seconds. Plates, dielectric, and oil MUST
BE CLEAN!... BTW The cheapest and most common plate material is
aluminum. In the rolled cap, aluminum flashing is available
precut in a perfect plate width, and there are other widths
available. Flat plate caps can use flashing, but it is frequently
more cost effective to use foil.

Now that we have established a few basics, lets talk plate cap
design. The first type of flat stacked plate requires the cap be
pumped down to a pretty hard vacuum to remove air. This is the
horizontal stacked plate capacitor. Typically these are built in
a Tupperware type storage box. Plastic, plate, plastic, plate
etc. are stacked one atop the other to build up the value. The
breakdown voltage is directly related to the dielectric thick-
ness used. 60 mil poly sheet is recommended and will have a
breakdown voltage in the Tesla tank circuit between 11-17 kv
rms input voltage depending on the quality of material, and the
cleanliness of the construction.

Once the box is filled, and all parallel plate connections are
made, high current busses are brought through the lid of the
container and sealed airtight with hot glue. Then the lid is
snapped on, and it too is sealed with a bead of hot glue around
the edges. The next part is important: A single hole is made in
the lid for the vacuum connection. A fitting is hot glued into
the hole and a hose is attached to the vacuum pump. The cap is
pumped down, then the hose is clamped off and disconnected with-
out allowing air back into the cap. Submerge the hose in a bucket
of clean mineral oil and release the clamp. This allows the oil
to backfill the capacitor, and displaces the air that was
removed. Once backfilled to normal pressure, I pump them down a
second time, and repeat the procedure to make sure that all
trapped air between the plates is removed. Air bubbles will form
corona hot spots that will cause dielectric failure.

The vertical stacked plate capacitor is much like the cap I just
covered. But the vertical cap does not require pumpdown. A tank
is used to hold the veritcally stacked plates and dielectrics.
The unit I examined was built in a glass fishtank that employed
no metal in construction. Dense foam padding was set in the
bottom of the tank, and wedged in around the sides of the
vertical capacitor stack to cushion it and hold it in place. The
foam padding also reduced the mineral oil required to cover the
stack. The reason these caps do not require pumpdown is that
eventually the oil will displace the air trapped in the unit. A
break in period of low voltage operation assists the removal of
trapped air, as the pulsing of the cap vibrates the plates and
agitates the air bubbles free. The disadvantage of the unit I
examined was the glass fishtank. I have seen plastic waste cans
that could be cut down for use as a tank in this construction.

Higher Qs, higher voltage, and additional capacitance in stacked
plate capacitors can be easily obtained. The trick is to use
thinner dielectric.

Now the dielectric strength of polyethylene is given as
1000 volts per mil, but this is not the case in Tesla coils.
The standard breakdown voltages of a dielectric are calculated
using DC voltage. When you run AC across the dielectric, the
breakdown voltage must be divided by two. Then you must figure
that the peak voltage from a AC sine wave is higher than the
rms voltage most people go by. You meter won't see it, but your
dielectric will. Then you have resonate rise in the Tesla tank
circuit. To give you an idea of resonate rise in a tank, think
about the tidal forces that can be created with timed pushes in a
bathtub. It don't take much energy to push water over the side.
The same principal operates in the tank circuit in a coil,
especially with a synchronous gap system. The current pulsing
back and forth from capacitor plate to capacitor plate causes a
voltage rise that appears on the dielectric in the capacitors.
The standard 60 mil poly is supposed to hold up to 60,000 volts
per the book. I have blown holes through 60 mil poly with a 12 kv
neon sign xfrmr in a Tesla tank circuit and my gap wide open. My
pinky finger fit inside the hole.

One of the neatest homemade stack plate caps I have seen was
built by Bill Richards of T.C.B.O.R., the cost was pretty low,
the materials came from his laundry room, the grocery store, and
the drugstore. The only thing required was 56 hours of time in
arranging the plates according to Bill. But he did end up with
.03 uf 15 kv pulse capacitor in a five gallon bucket. It was
quite a performer on his coil at 3600 watts!

He shopped around for one gallon ziplock freezer bags with a 3
mil thickness. With a sharp scissors he cut the ziplocks off of
the tops of the bags. Then he cut aluminum foil squares that fit
inside the bag leaving a 1/2" of space around all four sides of
the plate. So the plate had dielectric borders 1/2" on all sides.

When two bags were stacked on top of one another, there were two
layers of dielectric, for a total of 6 mils. Being practical,
Bill figured correctly that the stacked bags would hold up to at
least 1000 volts rms input in the Tesla tank. He built up stacks
that had a value of about .45 uf each, with each stack rated at
1000 volts. Then he wired stacks in series.

By squeezing fifteen stacks vertically into a bucket, and
covering the whole thing in about three gallons of mineral oil,
he got the required capacitance at the required voltage. Since
the electrical forces are so well distributed among hundreds of
dielectrics, he had plenty of breakdown safety margin. He gave
the unit a couple of days to rest after construction, topping it
up with oil as required, and gave her the works at 15 kv on a big
coil. The heavy buss wiring never even got warm, and even though
it bubbled out enough air to displace a few more pints of oil, it
did not break down.

It turns out that this is a homemade version of commercial pulse
discharging capacitors. Stacked capacitor sections of very high
value are placed in series until the proper voltage requirement
is met. The cap has a very high Q because all of the plates are
very close together, with a minimum of connections and bussing
required. They deliver a very sharp pulse discharge.

Bill's cap was pretty cramped in the bucket. Because of the
square shape of the bags, a rectangular tank would have made
things easier to fit and wire. But he ran his buss bars through
the side of the bucket (sealed with hot glue) and by snapping on
the lid, he could pick it up by the handle and move it around
with ease.

The novice coiler should think about the capacitor requirements
and experiment some before beginning large scale homemade caps.
Shop for materials; frequently a wholesaler can be found where
bulk products (like mineral oil in 5 gallon pails) can be
purchased for a fraction of the retail cost. But just because
you don't have some big bang pulse caps on line does not mean
that you should wait to begin firing a small coil. Nearly every
beginner gets hir feet wet in salt water capacitors.

Tesla used salt water tanks in Colorado Springs. A tribute to the
genius of the man was his ability to develop his huge peak
powers using low Q saltwater/glass caps. I do not recommend glass
as a dielectric for coiling work. The dielectric constant is much
better than plastic, but the RF dissipation factor is so great
that they can rupture from dielectric heating (even in salt water
the trapped water under the bottles does not circulate) and they
always give a spindly, violet colored spark. Polyethylene again
is the material of choice, and bottles and buckets can be
assembled in a couple of hours that will fire small stuff. I
mentioned he before that I have a friend who is firing 5 kVA
coils, and still using banks of salt water caps to keep his
investment down. As with any homemade capacitor, the salt water
must be covered in oil to suppress surface corona. But the
quality of oil need not be high, and the capacitors need not be
exceptionally clean. A saturated solution of rock salt is all
that is needed for the plates.

I think I have accomplished what I intended to say on this
subject. As always, I am happy to respond on any unclear areas,
the need for additional information, or to note corrections.
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Date: 07-04-94 15:30
From: James Meyer
To: Richard Quick
Subj: Tesla Coils
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On 07-01-94, RICHARD QUICK wrote to DON KIMBERLIN and said:

RQ> He had a quirk about doing a lot of things in multiples of
RQ>three. He ran three phases in his 60 cycle work, but he also
RQ>liked the motor design that 60 cycle offered.

Three phase supplys make the motor design simpler. Even if
Tesla had a quirk, he was still an engineer and chose the
easier solution.

RQ> There would be no "induction", "circulating currents" or
RQ> disturbances. Tesla saw the earth as a giant resonator when
RQ> electricity at the properly tuned frequencies was conducted
RQ>into it.

My reading leads me to believe that Tesla was expecting the
resonance to be set up in the cavity that exists between the
ionosphere and the earth's surface. Both the ionosphere and
the Earth are conductors. They are separated by a pretty
good insulator, the air. The Earth wouldn't be resonant by
its self.

As to whether Tesla actually knew that the ionsphere existed,
I'm not sure. I think that he believed that even if it
didn't exist before, that his high voltage coils would
actually create an ionosphere.

His big towers were (I believe) an attempt to get one of the
terminals of his coils high enough into the air to enable it
to couple energy into the ionosphere. The other terminal was
already pretty well connected to the earth.

The only thing Tesla didn't take into account was the fact
that neither the Earth nor the ionosphere are perfect, or
even very good, conductors. The losses involved would make
the transmission of power through either one very
inefficient. Even though the electric power companies today
use an "earth ground", they don't try to pass any
current through the earth. The ground is there for safety
purposes.

RQ> Funny thing today however. My brother was telling me his
RQ>vision of the same thing: earthquakes, tidal waves, volcanos.
RQ>But he was confusing mechanical resonance with electrical
RQ>resonance. Tesla was an expert with both, and once stated that
RQ>given enough TNT it was possible to cause major fractures in
RQ>the earth's crust by timing a series of detonations.

And then there's the story about a small device that Tesla
made that could sense tiny vibrations in any object, amplify
them, and feed them back into that object. The story goes
that he clamped his pocket-sized device onto a steel
supporting post in the basement of his New York laboratory
and switched it on. Within a few minutes it had picked up
the natural resonant vibrations of the building and
surrounding land and begun to amplify them. Shortly
thereafter, the whole area began to vibrate. It was after
several cracks appeared in the building, and I think others
nearby, that Tesla realized what could happen. He reportedly
shut the device off and smashed it into little pieces so that
nobody else could get hold of something that simple and yet
so dangerous. Since Tesla very seldom made any drawings or
notes for things that he built for himself, the exact
configuration of that machine was lost forever.

RQ> But back to the wireless power transmission using cavity
RQ> resonate properties of the earth. The way I see Magnifing
RQ> Transmitter is more like a pump. The high voltage field
RQ> maintained on the smooth toroid (air terminal) forces energy
RQ> into the ground.

Again, I see something differently. The cavity you speak of
isn't the ground. Jim, Durham, NC (1:3641/1)
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Date: 07-04-94 17:28
From: Richard Quick
To: All
Subj: Tesla, dischargers
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>archives 11/94 Toroid Discharge Terminals

A feature of the "classic" Tesla coil design is the sphere
or ball discharge terminal. Tesla clearly was using spheres while
he was developing the Colorado Springs oscillator, but during his
work there he made the discovery of toroids. Photographs of the
Colorado Springs machine clearly shows a brass toroid as part of
the antenna mast to prevent corona leakage and premature breakout
from the top of the extra coil.

As we examine photos of the Wardenclyff machine he built on Long
Island, it is clear that the entire tower was constructed to
carry the giant toroid terminal. I do not have verifiable infor-
mation as to the exact size of this terminal, but it is easily
over 50' in diameter. Probably closer to 75-100'. Toroids perform
several functions as discharge terminals on Tesla coils.

They provide a large top capacitance. This top capacitance helps
"cancel" the high inductance in the secondary coil, and increase
throughput in the system.

They break down at much higher voltages than other shapes. The
donut shaped field distributes the charge density. Higher
voltages must reached before electrical breakdown occurs. To the
coiler this means longer, higher voltage spark. For those of you
that have my video, you can see a 30% increase in spark lengths
with no change to input power, the only thing I did was add a
larger toroid and retune the system.

Toroids sever the coupling. This may be a controversial statement
on my part. But from what I have seen, appears to be true. A
sphere discharge terminal does not want to separate from the
field flux interactions between the primary and secondary. The
primary field flux wants to couple the sphere discharger into the
system as if it were another turn of the secondary. The spark
from the discharger will frequently follow these lines of force,
and seek to strike back to the primary. The spark discharge bends
back down, and aligns itself with the magnetic lines of force.

While this may be useful if you wish to visualize the size and
shape of the field, it does nothing to increase your spark
lengths. A large toroid on the other hand will establish a field
identity that interacts destructively with the primary/secondary
field flux. Since this destructive interaction occurs above the
top turns of the secondary is does not affect the coil perform-
ance or ability to process energy. It does however allow the
spark to leave the system unaffected by the primary/secondary
lines of force. This has the effect of allowing a clean getaway
for the discharge and promotes those long strikes to the ground
or other more distant objects.

Toroids also have the beneficial effect of lowering the frequency
of the secondary coil dramatically. By loading a large toroid on
a relatively small coil, a very low secondary frequency is
reached. Low frequency in Tesla systems means long spark. This
way a small coil can give big coil performance. Because of this
ability of the toroid to drop the frequency of the secondary to
such low frequencies, it is important to have a very large
primary available that can be tapped out to over 10-12 turns in
order to regain the system tune. Larger capacitors may be added,
but my experience shows that no additional power or capacitance
is required to get big increases in spark production.

Clearly the toroid is the ultimate in high Q dischargers in Tesla
systems. Now go out and buy one. I can hear Dave Halliday now....
> "You Paid _HOW MUCH?_"!!!
Yup, spun aluminum toroids are available commercially, and they
run hundreds, even thousands of dollars each. My 20" wide by 5"
high commercial toroid ran me over 350 clams. My ten inch
secondary needs a toroid at least twice as big to achieve optimum
performance, and as commercial toroids get larger, the price
increases exponentially. I priced a 40" toroid for my coil at
$2000.00 not including shipping, and they gave me a six month
delivery time...

So I built one for $35.00, and it works GREAT! I will never spend
another penny on commercial spun aluminum toroids. Here are the
brief instructions:

I buy the 4" or 6" diam. polyproplyene flexible black plastic
drain piping. This is made out of ridged plastic, so it does not
have a smooth surface, but it easy to bend to form circles of
varying diameters.

I cut the flange off with a sharp knife, match the ends, and tape
them together with wide plastic tape. Once a large ring is
formed, I cover the entire surface with wide plastic tape to
smooth out the ridges in the material. The goal is to have an
even, smooth, surface. The tape choice helps with this con-
struction, Mylar and other tapes have no stretch, and are
difficult to work with as they wrinkle. I shopped several stores
before I found a stretchy material similar to electrical tape.
Tape is applied in overlapping strips, or bands, around the drain
pipe 4" or 6" cross section. Some surface irregularities are OK.

Once the ring is smoothed with a layer of plastic tape, I retape
the entire ring with aluminum plumbers tape. This tape comes in
two standard widths, I bought a large roll of each. Apply strips
of plumbers tape over the prepared surface, make sure the entire
surface is covered, and press out any wrinkles with a fingernail
or tool. You should now have an aluminized ring. Cut out a circle
of thin masonite, wood paneling, or thin plastic so that it will
friction fit in the center of the aluminized ring. Place some
blocks up under this panel, set the ring in place, and tape the
edges all around on both sides with aluminum tape to hold it in
place. Spray adhesive and heavy duty foil are used to cover both
sides if the center plate. Roll out all wrinkles with a socket or
a wood dowel. Works great, about 1/100th the cost.

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Date: 07-06-94 15:43
From: Richard Quick
To: Don Kimberlin
Subj: Electrical Octives
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Don, I picked this up from you in the thread "Phone Line
Resistance"

-=> Sez Don Kimberlin to Alan Hess about line resistance <=-

DK> ...The other source of "echoes" in local plant is improper
DK> terminating impedances. Matching the impedance of a piece
DK> of copper in local telephone plant is an approximation at
DK> best, when one understands that it's rare to ever have
DK> a piece of wire that's even a quarter wavelength at audio
DK> frequencies, and most are some random fraction. When you
DK> consider that even only 300 - 3000 Hertz covers about 3-1/2
DK> octaves, you see that's an even more complex problem....

Interesting thought.

Could you please expand a bit on the relationship between 300 -
3000 Hertz and 3-1/2 octaves? Are there 1000 Hertz in an octave?

I understand that a relationship of eighths and frequency exists,
but I guess that my problem is that I have no musical talent, and
I am at a complete loss as to how many Hertz make up an octave,
or what the precise relationship is when spanning frequencies. I
have a pretty clear understanding of the basic physics involved;
I understand how string vibrations produce a note, I understand
basic wave motion, frequencies, and harmonics. I have studied
some transmission line applications in my coiling work and as a
result I am very familiar with 1/16th, 1/8th, 1/4, etc., outputs.

Given the current and voltage relationships in a transmission
line it is clear and natural to me that an 1/8th based system of
division applies when discussing a wavelength at a specific
frequency. But when thinking about a range of frequencies, I
don't understand how what is to me an "unintelligible" music
based system (octaves) relates. Blame it on my music teacher.

I really would appreciate it if you would take some time and
explain this. Many times while reading/translating technical
text from the past (1890-1910) I have seen the word "octave"
tossed around by the old radio guys. Tesla uses it specifically
on several occasions in the Colorado Springs Notes in context
nearly identical to yours.

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Date: 07-06-94 21:00
From: Richard Quick
To: James Meyer
Subj: Tesla Coils
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This one is good folks... We are talking about Tesla's global
power xmission scheme.

JM> My reading leads me to believe that Tesla was expecting the
JM> resonance to be set up in the cavity that exists between the
JM> ionosphere and the earth's surface. Both the ionosphere and
JM> the Earth are conductors. They are separated by a pretty
JM> good insulator, the air. The Earth wouldn't be resonant by
JM> its self.

Good point, and one I am happy to discuss. My reading and experi-
mentation lead to other, perhaps more likely, explanations.
>NICKOLA TESLA ON HIS WORK WITH ALTERNATING CURRENTS AND THEIR
>APPLICATION TO WIRELESS TELEGRAPHY, TELEPHONY, AND TRANSMISSION
>OF POWER.
This is a fine product of a modern legal research is edited by
Leland I. Anderson, published in 1992 (Library of Congress Cat.
92-60482, ISBN 0-9632652-0-2) by Sun Publishing, Div. of Boyle &
Anderson, Denver, CO., 80219, and available from; 21st Century
Books, Box 2001, Breckenridge, CO. 80424. This book is the
transcript of Tesla's pre-hearing interview conducted by his
legal counsel in 1916. The interview was precipitated by a number
of pending court cases in the fledgling radio industry. One of
the attorneys conducting the interview held an EE degree. Photos,
patent covers, schematics, mechanical drawings, etc. were
submitted by Tesla as the stenographer recorded his answers and
explanations. None of this material was intended for print, most
has never been published before, and there is no question as to
accuracy or authenticity. His testimony and depositions led to a
US Supreme Court decision in his favor 1943.

JM> As to whether Tesla actually knew that the ionsphere
JM> existed, I'm not sure.

I would have to believe the answer was yes, but to Tesla I don't
think it really mattered. He was very aware of the conductivity
of low pressure gas, which mattered very much to the man who
invented the waveguide. HV RF conduction through a low pressure
gas; not radiation, not induction; is a key part of Tesla's
global pathway. He clearly shows it in US Patent No. 645,576 &
649,621 filed Sept 2, 1897. He was refused these patents due to
several objections by the patent office, namely that the machine
could not work. Tesla invited the U.S. Patent Office Examiner in
Chief, G.D. Seeley, to his Houston street lab. A demonstration
and explanation was given to Mr. Seeley Jan 23, 1898. The patent
that followed clearly states that the machine transmits electri-
cal power in industrial quantities without wires. It's referenced
in many places, and worth looking at. BTW, Lord Kelvin also dis-
cussed various aspects of the idea with Tesla. Kelvin too came to
Houston street lab during the month of September 1897, and stated
afterwards that there were no flaws in the idea, and that it was
both practical and reasonable.

JM> I think that he believed that even if it didn't exist
JM> before, that his high voltage coils would actually create an
JM> ionosphere. His big towers were (I believe) an attempt to
JM> get one of the terminals of his coils high enough into the
JM> air to enable it to couple energy into the ionosphere.

Not as Tesla explains it. Tesla stated that he had the technology
to create a conductive channel from the air terminal of the
Magnifying Transmitter into the lower stratosphere, where
conduction would occur freely. I will quote Tesla from the legal
document referenced above, pp 110,:

NT> I have constructed and patented a form of apparatus which,
NT> with a moderate elevation of a few hundred feet, can break
NT> the air stratum down. You will then see something like an
NT> aurora borealis across the sky, and the energy will go to the
NT> distant place.

I am not going to second guess Tesla here as to which specific
apparatus, or how it was to be employed, but in the "Colorado
Springs Notes" (Nolit, Beograde, pp 29, referenced prev.) Tesla
shows us sketches of very powerful X-Ray tubes that require no
return wire (single terminal bulbs like these were demonstrated
by Tesla in 1891, and he held several patents). One of these
tubes took clear X-Ray photos of Mr. Alley's skull at a distance
of 40 feet with an exposure time Tesla estimated at 1/10th of a
second. Tesla also had hard UV tubes (single terminal as above).
Could these tubes perhaps ionize a conductive air channel into
the lower stratosphere? Were the aurora borealis effects reported
by Colorado Springs residents in 1899-1900 around Tesla's lab the
system in actual operation? Me thinks perhaps...

JM> The other terminal was already pretty well connected to the
JM> earth.

We agree 100% here. So would Tesla.

JM> The only thing Tesla didn't take into account was the fact
JM> that neither the Earth nor the ionosphere are perfect, or
JM> even very good, conductors. The losses involved would make
JM> the transmission of power through either one very
JM> inefficient. Even though the electric power companies today
JM> use an "earth ground", they don't try to pass any
JM> current through the earth. The ground is there for safety
JM> purposes.

Tesla disagrees. He describes the planet and it's atmosphere as
two nearly perfect conductors separated by a thin layer of dense
non-conducting atmosphere. There is not space in this post to
quote all of the text in the long titled reference I am using,
but Tesla's counsel raised the very questions you do in 1916.
Tesla responds to the question first with simple explanation,
then analogue. When the attorney finally begins to understand his
explanation, he replies that if what Tesla states is true then
those who are using his radio patents are using it backwards...

NT> With my system, I can convey to a distant point millions of
NT> times the energy they transmit.

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 07-02-94 01:25
From: Richard Quick
To: Don Kimberlin
Subj: Tesla Coils
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
We were talking about the conductivity of earth grounds...

RQ>What about earth resonate (electrically conducted)
RQ>frequencies?

DK> ...Does this get off into the area of Tesla determining the
DK> resonant frequencies of the planet? Does the 50/60 Hertz
DK power frequencies figure into this?

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 07-05-94 00:32
From: Don Kimberlin
To: Richard Quick
Subj: Tesla Coils
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
...Mike Procospo wrote to all:

MP> I'm interested in making a telsa coil for a little
MP> experiment of mine, could any of you write to me with some
MP> information on how I would go about doing this? Thankz a lot

...Looks like it's time to rewind the tape and start it over
again, Richard <smirkle> Concord,N.C. (704)792-9241 (1:379/37)

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 07-07-94 16:59
From: Dave Halliday
To: Richard Quick
Subj: Tesla Coils
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
RQ| DH> Just dropping a note to let you know that I am still
| DH> incredibly busy...

RQ|Yes I knew you were out there lurking, and figured you were
|overworking yourself. I hope you have been saving stuff.

You bet! Been hitting the [S]ave button frequently!

Things have always slowed down during the summer and I was
expecting the same but it kept getting busier and busier - I kept
putting off hiring another person because I knew that as soon as
I did, it would go back to "normal" summer business and we would
be sitting around staring at the walls... Right...

Only problem now is that the durn cash drawer gets too full to
close - gotta take it to the bank every few days - either that or
shred the stuff... <g>

RQ|Well, there is no doubt that using pole pigs in experiments
|like this requires some hefty ballast. For those that have not
|been following this for over half a year, I will restate.

RQ|A "pole pig" is one of those electric utility cans that sit on

|high voltage power supplies they are be reversed. The cores on
|these type xfmrs are "shell" wound. They do not saturate, and
|they will dim an entire neighborhood unless they are
|externally current limited.

You are firing your coil and inadvertently browning out the
entire neighborhood. Over the wolverine sound of the spark gaps,
you hear a muttering noise, you turn around and it is your
neighbors, carrying torches, storming the gates of... <g>

RQ|I have used an arc welder in series with one leg of the 240
|volt input on the xfmrs (when run for HV supplies) to limit
|current. In this use, the shunted core of the arc welder
|performs the <task of limiting current>

|<many> pounds of iron core and copper wire here. The resulting
|inductive delay is real, and it takes a second or two for the
|current flow to stabilize through the control circuits. This
|may not seem like a problem, but it is like driving a strange
|car with gross oversteer. Learning to handle the controls
|smoothly can be a bit nerve wracking at first.

I can imagine, especially if you are tinkering with the setup:
adjusting the gaps, providing different discharge paths etc...

Kinda like a phase-lock-loop on a bad hair day! I have worked
with the 4069 PLL chip and that is a really nice one unless you
have the error-voltage filter time constants set too high - it is
like trying to heard a bunch of cats getting it to settle down!

RQ|Another common method used to current limit pole pigs is
|resistive ballast. Paralleled high load resistance is added

|resistive ballast. The problem with these are two fold; things
|get very hot in a hurry (which is really no problem in winter,
|but in a garage in August...), and there is a greater voltage

I was figuring this would happen...

|drop across the primary in the pig than is typical of purely
|inductive ballast. The advantage: the power supply limited
|with resistive ballast is smooth as silk; no inductive delay,
|the power comes up surely and slowly, no tugging on the
|variacs, and no sparking on the variac brushes.

NICE!

DH> The work on the controller is going well - I have not
DH> hooked it up to the variacs yet - it's still at the store
DH> but it works well. Anyway, I will keep you posted

RQ|Sounds great!

I will be writing it up in the TCBA news when I get everything up
and running - should be a fun project by itself!

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 07-04-94 14:00
From: Richard Quick
To: Mike Procospo
Subj: Tesla Coil,xfmr,1/2
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
> From archives
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 11-05-93
From: Richard Quick
To: All
Subj: 10KVA Tesla Coil
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
If you are interested in making a high voltage, high current,
power supply, I can tell you how to do it for free....

This should read C = Corrected kVA times (10 to the ninth power)
over, (2 pi times f times e squared)

C = required capacitance in microfarads
f = frequency of applied voltage
e = applied voltage

Corrected kVA is determined by dividing the volt*amps (watts)
output of the neon sign xfrmr by 1000

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 07-04-94 01:24
From: Richard Quick
To: Mike Procospo
Subj: Tesla Coils
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
><Imported from Archives, 11/10/93 to DH & 10/10/93 to DB

DB> How did you go about winding your coil? What are the specs?

The first step in winding a coil is to select a coil form. The
coil form should be a low loss material (we are talking RF
losses) like polyethylene, polystyrene, or polypropylene,
Plexiglas, or Lexan: but the most common material is PVC plastic
drain pipe (thinnest wall is best) which is high loss. I used a
section of PVC thin wall flume duct.

I dug that up as it pretty much explains things, and you may have
missed the post.

DH> What determines a certain plastics being good?

The terminal capacitance must have a diameter greater than the
coil form, or spark will break out; either from the top of coil,
or from the air wound turns connecting the coil to the terminal.

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 7-09-94 14:27
From: Terry Smith
To: Richard Quick
Subj: crossed wires
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
MC> .... crossing turns on a tesla coil...

RQ> ... the lower turns <on a coil> can act as a low
RQ> voltage "ground" point. Crosses between turns (especially on
RQ> short fat coils with high interturn voltage increases)
RQ> results in tiny breakdowns in the magnet wire insulation.

In many RF chokes, closely spaced turns over most of a coil may
be spaced out ncreasingly toward a "hot" end, in order to avoid
both heating and voltage arc over problems. Terry (203)732-0575
(1:141/1275)

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 07-08-94 09:27
From: Mike Procospo
To: Richard Quick
Subj: Tesla Coil,xfmr,2/2 (Tesla Power Supplies)
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
RQ>Rebuilt units need a little protection from the high voltage
RQ>secondary outputs. The first thing I do...

Thanks this is gonna help me out a lot. (407)323-0025 (1:363/77)

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 07-10-94 01:56
From: Richard Quick
To: Don Kimberlin
Subj: Tesla Coils
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
DK> ...Mike Procospo wrote to all:

MP> I'm interested in making a telsa coil...

DK> ...Looks like it's time to rewind the tape and start it over
DK> Richard <smirkel>

Well it really isn't that bad. By now I have stored text files
where I save my "Top Ten Tesla Requests", and what took hours to
put together the first time can be cut, pasted, and revised if
needed in a few minutes.

Still, I try to add new material whenever I post, otherwise we
would all get bored to death. I find myself learning more as I
organize my thoughts and references in an effort to supply the
most accurate and up to date information as possible. Other
people direct and spin off topics, which broadens interest.

There are a lot of requests for information on this subject. My
archives of this and related threads go back to Oct 1993 and have
been very popular. I have 95% or more of it on disk, along with
related GIF files showing spark gap mechanical drawings. I will
send a copy free to anybody who mails me a blank 1.44 mb floppy
and a postage pre-paid mailer.

Tesla is becoming an area of popular interest. I do appreciate
the time that you and others have given towards intelligent
input. Without quality people like yourself out here (and more
joining in all the time) posting would be a waste of time.

Thanks!
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 07-08-94 20:14
From: Richard Quick
To: James Meyer
Subj: Tesla Coils
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Still rambling along about the Tesla global power scheme...

I wanted to point out the bottom line in this discussion before
I take off rambling again. First and foremost: I am not positive
that Tesla's global transmission system, using wireless stations
for worldwide power and communications transmission, is possible.
However, I am absolutely sure that Tesla believed to his death
bed that his system worked.

Looking at some of Tesla's history; patents granted, patent
applications, lectures, notes, photos, drawings, and interviews,
not to mention commentary by others; there emerges a picture of a
most unusual, but very accurate, scientific mind. Given his docu-
mentable record of logical thinking, one tends to defer to Tesla.
It must be understood that much of the public perceptions of
Tesla's work is tempered by three things; he was a boastful
showman, he had odd (but elegant) personal habits, and he was
talked about greatly behind his back; regardless, he was a first
rate electrical-mechanical engineer and theorist.

He sunk practically every penny he ever made (well over
$2,000,000 by 1915) above room, board, and clothing, towards
his oft stated lifetime goal of bringing electrical power and
communications to the entire globe. He succeeded with low fre-
quency AC (the "modern" Tesla Polyphase system still in use)
prior to 1887. By 1891 he had radio patents, lectured on single
wire power transmission systems and was showing off his single
terminal bulbs. His work progressed, (despite the setback of a
fire), at a feverish pace through the mid 1890s. Tesla developed
multiplexing, base feeding resonate structures, and sensitive
recievers, to name a few. By 1897 the first wireless power
transmission patents appear, and Tesla demonstrates the working
model in his Houston street lab. In 1899 Tesla perfected
Magnifier (three coil) arrangement as the power processor for the
wireless system and peaks his experimental station at Colorado
Springs in 1900. See text pp107: NT ON HIS WORK W/ALTERNATING
CURRENTS and THEIR APPLICATION to WIRELESS TELEGRAPHY, TELE...

NT> I had in my Colorado plant a current of 1,000 amperes in the
NT> antenna. The biggest radio plants of today (1916) develop
NT> something like 200 or 250 amperes in the antenna. Remember,
NT> also, that my current was under a great tension. My current
NT> was under a tension of 3 1/2 or 4 million volts, others only
NT> 30,000 volts; so you can imagine the enormous difference
NT> between the energy of the vibrations which I produced and
NT> those in the present plants.

I put that lower end peak power for Dr. Tesla = 3.5 gigawatts vs.
Marconi and Co. upper end peak powers at only 7.5 megawatts.
Tesla was running peak powers an order of magnitude larger than
Marconi, and he was doing it years earlier. Some of the detailed
description on performance characteristics of the Colorado
Springs machine's tank circuits and resonators as it evolves into
the powerful signal generator which is the heart of the global
wireless system is inspiring...

NT> It is a notable observation that these "extra coils" with one
NT> of the terminals free, enable the obtainment of practically
NT> ANY (emphasis in original) e.m.f. the limits being so far
NT> remote, that I would not hesitate in undertaking to produce
NT> sparks of thousands of feet in length in this manner. Owing
NT> to this feature I expect that this method of raising the
NT> e.m.f. with an open coil will be recognized later as a
NT> material and beautiful advancement in the art.

See Colorado Springs Notes pp79 for the above quote, pp115
fig. 5 for a dual resonator schematic that produces ball
lightning (entry Jul 30 1899) pp 162 for another (Aug 26 1899),
some wicked oscillator tank circuits and coupling ideas pp 154-
157, mid-August 1899; one of the parallel circuits here was later
used to advantage on the Phermex 50 MHz accelerator in the 1980s.

He relates that the experiments conducted at Colorado Springs
station were very successful on an industrial scale system, and
that the Wardenclyff plant was commercial by design.

This brings me to conclude: either Tesla was lying, or he really
had something. I propose that Tesla was the world's foremost
expert in power processing systems, and that the Magnifying
Transmitter with base fed open end resonators (extra coil, earth)
was the culmination of his life's work in this field. Tesla
stated over and over that not only was his theory valid, but that
he had built, tested, and operated more than one system. Many
notables of the era, Helmholtz, Lord Kelvin, and Seeley, to name
a few, were throughly convinced Tesla was telling the truth...

If he was telling the truth, then we are obligated at the very
least to try to understand the system accurately.

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 07-08-94 20:11
From: Richard Quick
To: Dave Halliday
Subj: Tesla Coils
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
We were talking about external current limiting on xfmrs...

RQ> these type xfmrs are "shell" wound. They do not saturate,
RQ> and they will dim an entire neighborhood unless they are
RQ> externally current limited.

DH> Over the wolverine sound of the spark gaps, you hear a
DH> muttering noise, you turn around and it is your neighbors,
DH> carrying torches, storming the gates of... <g>

I wouldn't grin too much. It has happened and leaves one feeling
somewhat humbled. Watching the towns people gather, torches in
their hands and anger on their faces, is certainly merry fun...
Until they come breaking down your door! I have a compressed air
quenched gap that when fired at over 1000 watts (3, 12kv 30ma
neons) requires hearing protection. The pure performance and peak
power delivered by this gap is excellent in every respect, but
the noise is not tolerable unless the gaps are enclosed.

Remember too that externally limited xfrmrs (potential, pole pig,
plate) require more sophisticated gap systems than neon powered
coils, with most coilers going with rotary gaps at this point...
I saw a museum coil fired once that had a rotary gap system made
up of eight or so 1/4 x 20 brass machine screws mounted around
the perimeter of a 5" metal disk. The disk was threaded onto one
end of a Black and Decker pedestal mount grinder. It worked
great, but the replaceable brass screws used for the rotating
electrodes were melted, burned and ablated rapidly. It was not
properly shielded and the gap pelted me with tiny BB like
droplets of molten brass and hot slag that easily penetrated my
clothes. The coil was running not much over 2500 watts with a 3
KVA potential xfmr. It was inductively limited by placing a large
Superior Electric Powerstat in series with the primary of the
potential xfrmr.

I have seen a number of coil plans that show variacs, powerstats,
autoxfrmrs, whatever, as an adjustable inductance (adjustable
inductive ballast) in series with the primary of the step up
xfrmr. I have found this practice questionable, though others
will surely disagree. These variable xfrmrs are shell wound on an
iron powder toroid. They are designed for low saturation, high
efficient variable voltage transformation with moderate to high
current throughputs. When they are used as a variable inductance
to limit current, the performance is very quirky; either the
current is all the way on, or it is all the way off, and there
are only two or three turns of winding where you have any (very
very sensitive!) adjustment at all between full on, and full off.
BTW, another characteristic of these variable transformers is
that when you short them (full on) they cook real fast.

Some people have cut a small wedge out of the toroid core on
these variable transformers when they are to be used as variable
inductance. The modification is permanent, but will assist a big
Powerstat in adapting to the new role of limiting current from
it's designed task as a variable xfrmr. But, IMO, even if the
variable xfrmr core is modified, resistive ballasting is still
required for smooth and safe control.

On the other hand, an arc welder core is designed with heavy
current limiting in mind. A bit of resistive ballast along with
the massive variable inductor helps with low power testing and
start ups. Once the circuits are brought up to full power the
resistive ballast aids in smoothing things out. The arc welder
alone as ballast opens up at about 2.2 KVA, that is if you
remember there is a 1-2 second delay and don't open it wider.
Once running it is manageable without resistance.

As far as what to use for resistive ballast: paralleled oven
elements from scrapped electric stoves may be inexpensively
assembled, electric heater elements (such as you already have)
work well, a 5 gallon plastic bucket filled with water can be
doped with a few teaspoons of baking soda (current is controlled
by rasing and lowering wet electrodes), incandescent bulb racks
have been used, and I have also seen ceramic toroids wrapped with
nichrome strap that can be used as variable ballast for sale
cheap at the local electronics surplus shop.

DH> I will be writing it up in the TCBA news when I get
DH> everything up and running - should be a fun project by
DH> itself!

Never a dull moment!

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 07-08-94 09:15
From: Mike Procospo
To: Richard Quick
Subj: Tesla Coils
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
RQ>><Imported from Archives, 11/10/93 to DH & 10/10/93 to DB

RQ> DB> How did you go about winding your coil?

RQ>The first step in winding a coil is to select a coil form.

Thanks again for you're help (407)323-0025 (1:363/77)

ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
Date: 07-09-94 11:30
From: Dave Halliday
To: Richard Quick
Subj: Tesla Coils 1/2
ДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДДД
RQ|We were talking about external current limiting on xfmrs...

RQ| RQ> these type xfmrs are "shell" wound. They do not saturate,
| RQ> and they will dim an entire neighborhood unless they are
| RQ> externally current limited.

RQ| DH> Over the wolverine sound of the spark gaps, you hear a
| DH> muttering noise, you turn around and it is your
| DH> neighbors, carrying torches, storming the gates of... <g>

RQ|I wouldn't grin too much. It has happened and leaves one
|feeling somewhat humbled. Watching the towns people gather,
|torches in their hands and anger on their faces, is certainly
|merry fun...

I have a next-door neighbor who will be a prime candidate when I
start firing at high power! He "retired" about 20 years ago and
is bored stiff - always curious about what I am up to... Was
interested in what I was doing when I sank the ground pipes into
my front yard a few months ago. Tesla WHAT? <grin>

|Until they come breaking down your door! I have a compressed
|air quenched gap that when fired at over 1000 watts (3, 12kv
|30ma neons) requires hearing protection. The pure performance
|and peak power delivered by this gap is excellent in every
|respect, but the noise is not tolerable unless the gaps are
|enclosed. RQ

Also, you had mentioned a fluid cooled gap - how's that one
going?

I saw in one of the articles in Wireless World about the old
spark-gap transmitters where they had the gap located in a
separate enclosed brick building.

I will be starting with the stationary gap you told me about -
several lengths of copper tubing inside of the PVC pipe with a
fan blowing through it but I have visions of doing a rotary gap
or one with a pulsed compressed air. I had thought that a
commercial audio high-frequency horn driver could be used to
"pulse" a flow of air and by varying the frequency you could
adjust the timing...

|I saw a museum coil fired once that had a rotary gap system
|made up of eight or so 1/4 x 20 brass machine screws mounted
|around the perimeter of a 5" metal disk. The disk was threaded
|onto one end of a Black and Decker pedestal mount grinder. It
|worked great, but the replaceable brass screws used for the
|rotating electrodes were melted, burned and ablated rapidly.
|It was not properly shielded and the gap pelted me with tiny
|BB like droplets of molten brass and hot slag that easily
|penetrated my

Welders call these slag drops "dingleberries"

There was an insert in my last copy of TCBA news for an
advertisement for a rotary gap using titanium electrodes. Didn't
mention a price though <ouch!>

|clothes. The coil was running not much over 2500 watts with a
|3 KVA potential xfmr. It was inductively limited by placing a
|large Superior Electric Powerstat in series with the primary
|of the potential xfrmr.

I have heard that theaters used to have variable reactance
dimmers for their lights - don't know if any are available or
what their time-constants are but that would be another avenue to
explore...

RQ|I have seen a number of coil plans that show variacs,
|powerstats, autoxfrmrs, whatever, as an adjustable inductance
|(adjustable inductive ballast) in series with the primary of
|the step up

|to limit current, the performance is very quirky; either the
|current is all the way on, or it is all the way off, and there
|are only two or three turns of winding where you have any
|(very very sensitive!) adjustment at all between full on, and
|full off. BTW, another characteristic of these variable
|transformers is that when you short them (full on) they cook
|real fast.

RQ|Some people have cut a small wedge out of the toroid core on
|these variable transformers when they are to be used as
|variable inductance. The modification is permanent, but will
|assist a big Powerstat in adapting to the new role of limiting
|current from it's designed task as a variable xfrmr. But, IMO,
|even if the variable xfrmr core is modified, resistive
|ballasting is still required for smooth and safe control.

Hmmmm... Maybe there could be a way to move a wedge in and out
of the toroid... Either that or rewind it with a heavier guage
of wire...

RQ|As far as what to use for resistive ballast: paralleled oven
|elements from scrapped electric stoves may be inexpensively
|assembled, electric heater elements (such as you already have)

I will start out with that and go from there. I had these from a
previous remodel and didn't throw them out because I figured I
would find a use somewhere...

RQ| DH> I will be writing it up in the TCBA news when I get
| DH> everything up and running - should be a fun project by
| DH> itself!

RQ|Never a dull moment!

You have that right!

Also, just noticed that Tesla's Birthday is this Sunday, July
10th

I think I will throw the main breaker to the house and then turn
it back on! Fiat lux big-time! 206) 528-1941 (1:343/210)

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