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By dictionary definition
of a Tesla coil is a step-up transformer with an air
core; used to produce high voltages at high frequencies, but to a
normal person its a device that makes lightning. The Tesla
coil was created by Nikola Tesla (July 9/July 10, 1856 - January 7,
1943), A pioneering physicist, inventor, and electrical engineer of
the late 18th Century and early 19th. The most common type of
coil is a resonant one, using a capacitor(s), coils and of course a
spark gap.
When it comes to choosing
a power source you have many different options such as neon sign
transformers, MOT's (Microwave oven transformers), OBITS (oil
burning ignition transformers) and of course the most extreme; The
Pole Pig transformer.
For my Tesla coil I will
use a 15kV 900W Neon Sign Transformer.
Choosing capacitors for
a Tesla coil is like choosing a particular grain of sand, you have so
many options and sizes. In my case, due to lack of funs I first
decided to make my own capacitors out of salt water. The salt water
capacitors are made by;
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Taking a Beer or
soda sized bottle, cover up to the neck in aluminum
tape.
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Then a layer of
electrical tape is applied to cover.
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Mix up a batch of
salt water (using as much salt as the water will handle) then pour
the water into the bottles only up to the foil line. After
it settles pour enough oil ( I used vegetable) on top, to take up
the space between the Foil line and the top of the bottle.
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Modifying
the screw lid is done with a drill, making a large enough hole to
place in a threaded rod held in place with two bolts.
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Now you have a Salt
Water Capacitor using the glass bottle as the dielectric.
 
Although
after testing with the salt water capacitors (they lose energy quite
easily but are still a cheap alternative) and with the addition of some more funds, I decided to
purchase enough polypropylene capacitors to create a capacitor bank or
MMC (Multi-mini-capacitor).
 
The Secondary Coils job is to produce
the very high voltages so we have to take extra care in making this
piece to avoid disappointment. The smaller coil is the one being
used, it took about 3 hours to wind it off the larger to coil to the
smaller one.
 Then
a thick layer ( Eight Layers) of polyurethane varnish is applied onto the
motorized rotating coil. This is mainly to protect the wire but also to
add extra insulation.
The Toroid has two functions; it acts
as an HV output terminal and also adds capacitance. I made my toroid
out of a round piece of flexible foam which was then covered in
aluminum tape.
 
The Spark Gap is a power switch
which uses air to conduct for the Tesla Coil.
(No Picture Yet)
And for a quite lash-up of the primary (the flat coil) and the
Secondary...
To be Continued..... |
