Tesla Coil

Project Synopsis

We would like to build a tesla coil for the mustache laser party (and beyond!)

Design Summary

<Insert schematic here>

Components

Secondary Coil

A secondary wound on an 8" piece of green PVC is already available for use. <insert details of wire and length here>

Primary Coil (NEED)

A flat inductor used as a resonator within the LC tank circuit which is magnetically coupled to the secondary. Needs to be tuned with the main capacitor to the resonant frequency of the secondary LC circuit.

Materials needed

2 ft square of plywood to mount. a number of radial supports to hold spiral shape in place. Small copper tubing in a flat spiral. 10-15 turns at 3/4" to 1" inch spacing starting at an 11"-12" diameter.

Suitable aligator clip for tuning

Transformer

A 12KV 30mA neon sign transformer and an 18KV (current rating unknown) transformer are available for use.

Spark Gap (NEED)

Discharges the energy stored in the main capacitor into the tank circuit. Forms the trigger for the relaxation oscillator once the capacitor charges to a specific voltage.

Materials needed

10x 1/2" to 1" copper pipe sections attached to a flat surface lain in parallel to form multiple small gaps of 1/8" to 1/4". Tuneable to using aligator clips to select different sections of pipe.

Aligator clips

Note: Zach has supplied 2ft of 1/2" copper pipe.

Main Capacitor

Stores energy until a certain voltage is reached, then discharges through the main spark gap and sets up a resonance between the primary coil.

An exponentially decaying RF waveform is produced until the energy is dissapated, recharging begins at the next 60Hz peak (discharge is therefore at 120Hz).

We already have a 30nF 35KV maxwell pulse capacitor designed for high frequency use.

Protection Inductors (NEED)

Provides a high impedance to RF in order to contain the RF within the tank circuit. Allows 60hz to pass unimpeded.

Materials needed

Magnet wire and wooden dowel. Target 10mH. Separate winding layers with an insulator to keep arcs from forming between the input and the output (which will have kilovolt potential differences)

Note: Will has supplied dowels of about 1/2" dia. left near the lathe, and Zach has magnet wire on the floor near the lathe. Zach has supplied 3ft of 5/8" dowel as well.

question: how many winding layers of how many turns each?

As many side-by-side turns as you can fit in a 4 inch length, make three layers and measure the inductance. We will go from there!

Protection Capacitors (NEED)

These shunt any RF energy that passes the RF chokes to ground instead of injecting it into the transformer secondary.

Materials needed

Two Old English 800 beer bottles, salt water, AL foil.

Protection Spark Gap (NEED)

A simple tunable spark gap consisting of a grounded middle section with a gap on either side to each leg of the transformer's differential output.

Materials needed

Three pieces of threaded rod, 1 to 2" long and polished as round as possible (to provide an even E field and predictable breakdown voltage).

Set each into a small wooden slat and use the threaded nature of the rods to tune the gaps. Or something like that.

Question: please elaborate on the construction/arrangement of the pieces, I.e. what do you mean by slat, how should the threading work, where do the rods go in relation to each other.

All three pieces will be end to end with a support in the center of each piece and a gap between the sections. The support will have a hole in it to match the rod,

so that it may be adjusted back and forth simply by rotating. It might make sense to center and tightly affix the centeral section.

Note: Zach has supplied 1/4"-20 threaded rod.

Discharge Terminal (NEED)

A smooth conductive surface to use as a capacitor in the LC secondary resonator assembly. A jack-O-electrons.

Materials needed

Pumpking, knife, evil