ee5391aa@hydra.unm.edu (Duke McMullan n5gax) (02/02/90)
Ahhhh, wonderful! The zappers are still around!
First; Tesla coils: What you do, you send a couple of bucks to
Lindsay's Electrical Books
PO Box 12
Bradley, IL 60915-0012
and ask for their catalog.
Lindsay offers the best selection of books on Tesla coils of which I'm aware,
hands down. Ford's _Tesla_Coil_Secrets_ is a bit pretentious, but one of the
best I've seen. Curtis' _High_Frequency_Apparatus_ runs a close second, but
is somewhat more general. Scott's _High_Voltage_Projects_ is promising, but I
haven't looked one over yet. The blurb shows that Scott gives a design for a
tube-type Tesla coil, as well as some others (likely spark-gap types) which are
rated at up to 375 kV. Not bad, for a start....
There's also a Tesla Coil Association of America, or some such. I can't find a
ref. in the Lindsay catalog...anyone?
73 Magazine had a Tesla Coil article a few years back...no more that 5 years,
I'm sure. Talk to a ham friend, or visit your library for this. 73 publishes
an annual index in the Dec. ish, it'll save time.
The much-lamented "Science and Mechanics" magazine published several tube-type
Tesla Coil designs back in the 1960's. Again, a library is the best bet.
(Parenthetically, I dug out an old Science & Mechanics mag a couple of years
back. I can't even remember why. I was looking through the thing, simply in-
nundating myself with maudlin nostalgia, when I did a double take at an ad in
the back:
S&M Kits
Sigh. How times change....)
I think my Lindsay catalog is a couple of years old, and they emphasize that
any of these titles may become unavailable at any time, but let's look at
a few highlights:
-- How many of you remember "The Amateur Scientist" column in "Scientific
American" back when Stong ran it? There was a collection of these
columns published under the column name, but it was unavailable for
years. Lindsay has it. It shows how to build telescopes, seismographs,
plasma jets (yeah...vaporize ANYTHING), X-ray machines, a linear ac-
celerator powered by a Van de Graaff generator, furnaces, diffusion
pumps, ad nausem. A marvelous, marvelous book.
-- Martin Gardner's _Fads_and_Fallacies_in_the_Name_of_Science_. Required read-
ing for all civilized people. WARNING: "New Age" people (whatever the
hell that means) are likely to be deeply offended by this book!
-- Books on perpetual motion, and many other dubious topics.
-- Lots and lots of "antique electronics" books. These things (such as the Tes-
la coil book mentioned first) are reprints of classics. They are clas-
sics for VERY good reasons.
-- A build-it-yourself welder.
-- Static electricity books (Van de Graaff generators, Wimshurst machines,etc.)
-- Old (and I mean OLD...circa 1920) radio books
-- Stuff on Nicola Tesla's mystical beliefs.
-- ...and the proverbial Lots, Lots More.
Second; Jacobs Ladders: All you need for this is a neon sign transformer and
an old coat hangar. You can be much fancier, of course. The traditional JL is
'V' shaped, but this isn't necessary. Simply insure that the smallest gap oc-
curs at the bottom. That is where the arc will strike. Above that, spacing may
vary as your taste demands. Ever consider a spiral JL?
There are some caveats. First, HIGH VOLTAGE. If you hit one of these with one
hand, you aren't likely to be electrocuted. You will experience one hell of a
severe shock, and probably get some burns on your hand. Don't do it. If you get
both hands in there, so that the current can flow through your chest cavity,
electrocution is a distinct possibility. Note that most neon sign transformers
are center-tapped and the tap connected to the case. If you have, say, 12 kV
transformer, that means that each terminal is hot to the tune of 6 kV with re-
spect to the case. It is wise to assume that this will also mean ~6kV with re-
spect to ground. The lesson? SHIELD THAT SUCKER! IT WILL BITE!
Another point -- the best JL I've ever built was with a 9kV transformer rated
at 120mA. That rather high current capability makes for an arc that'll spread
over a two-inch gap, and keeps spreading! It's really spectacular, compared
to most JLs I've seen. It can also fry you more easily, so we have to watch
out for this sort of thing.
Lessee...if you're mounting the rods on a wooden base (quit likely), make CER-
TAIN that the arc isn'n in contact with the wood when it strikes. I overlooked
this once, and the arc didn't climb. It carbonized the wood across the surface
between the two rods, and as the carbon in the little groove glowed red, hissed
and smoked, I was doing a bit of hissing and smoking of my own....
Last point -- make sure you have a NEON SIGN transformer. These are "shunt
wound", with the result that a short (which that arc is, approximately) across
the secondary won't result in a huge current draw on the primary, and the typ-
ical blown breaker which results. I tried building a Tesla coil once with a
high-current 8kV transformer I found. Plenty of current, but it wasn't shunt
wound. Every time we struck the arc, there went the breaker. Grrrrr....
(I THINK "shunt wound" is the correct terminology here. There's also a "shunt
wound" motor, but it has nothing to do with the transformer design.)
Lastly, the zappers: You will find an outfit advertised in the back of most of
the electronics magazines called "Information Unlimited." Actually, I under-
stand that this bunch is one person, Robert Lannini, dba Info. Unlim. A good
capitalist, by the sound of it. IU published a book with the compact title of
_Build_Your_Own_Laser,_Phaser,_Ion_Ray_Gun,_&_Other_Working_Space_Age_Projects_.
He shows how to build many things (including a flyback-transformer "Tesla" coil)
of interest, but here we'll confine our discussion to the "zappers": capacitive
discharge spark-makers. That's all they are; they make bright flashes; they
make big, loud cracks; they'll kill you if you get careless with them. Be
warned.
The book is available from numerous sources, including Lindsay.
Now, can we move the discussion to basement bombers, or should that be
in sci.chem?
:^) :') ;-) :^),
d
"So much karst; so little time...."
Duke McMullan n5gax nss13429r phon505-255-4642 ee5391aa@hydra.unm.eduhamlin@blackbird.afit.af.mil (Joe Hamlin) (02/04/90)
ee5391aa@hydra.unm.edu (Duke McMullan n5gax) writes: >There's also a Tesla Coil Association of America, or some such. I can't find a >ref. in the Lindsay catalog...anyone? The following is from an article posted to this group in May, 1989. It was included in a "summary" posting and not clear who actually supplied the info. Tesla Coil Builders' Association Harry Goldman RD3 Box 181 Glen Falls, NY 12801 (518) 792-1003 Newsletter: _TCBA News_, published 4 times per year. Subscription: $18/year US/Canada/Mexico (first class mail). $20 elsewhere surface mail, $28 airmail. Highschool students in US: $12/year with proof of student status (letter from school principal or teacher, on official school stationery). "TCBA NEWS is the official publication for the TESLA COIL BUILDERS' ASSOCIATION, an educational organization devoted to research and dissemination of information on the theory, construction and operation of the high voltage/high frequency transformer known as a Tesla coil." -- Joe Hamlin <hamlin@blackbird.afit.af.mil>