450 Watt Tesla Coil!!!

One fully operational 450 Watt Tesla Coil, built by yours truly just for giggles & laughs. The Tesla coil comprises a tank housing, an AC interface, a high voltage transformer, a pair of choke coils, an adjustable RQ-type spark gap, nine quart-sized bottle capacitors, primary and secondary coils, and a top terminal. Each of these components is described in greater detail below.

Tank Circuit:

Tank Housing: One wooden box, made of sturdy 3/4-inch thick wood, having a top, bottom and two walls. Tank housing assembled with 2-inch brass wood screws throughout. Two feet on the bottom of the tank housing are made of 3/4 x 1-inch strips of wood. As shown in the accompanying images, the tank circuit is installed within the tank housing while the secondary and primary coils are installed on top of the tank housing. Additionally, 14 gauge, solid copper wire is used throughout the tank circuit. The Tank Housing further comprises bottom- and side-mounted Plexiglas sheets that shield six bottle capacitors from the wood of the tank housing. The bottom Plexiglas sheet has two strips of aluminum tape upon which the six bottle capacitors are secured. The side-mounted Plexiglas sheet includes a Nylon belt which secures the bottle capacitors within the tank. The tank housing further includes a 1/4-20 bolt-stock and wing nut connector for an RF ground to the secondary coil, as well as a 1/4-20 bolt-stock and wing nut connector for attaching a tuning wire from the primary coil to the tank circuit.

AC Interface: One plastic housing with a female outlet, providing two grounded sockets. The housing has a child safety cover for added security. A great feature if you have children!!! The AC interface also includes an adapter with an on/off power switch. The Tesla coil is powered by plugging a three prong extension cord into the AC Interface, plugging the adapter into the other end to the extension cord, and then plugging the adapter into the wall. Pressing the power switch then fires the coil!!!

Transformer: One Franceformer neon sign transformer: 450 Watts; input 120 Volts; output 15,000 Volts@30 mA.

Choke Coils: Two coils of 14 gauge stranded wire, each comprising 26 turns. The choke coils are wound on white PVC tubing, 1 3/4 in diameter and 5 1/4 inches in length.

Spark Gap: One adjustable mini RQ-type spark gap. This spark gap is 4 inches in diameter, 4 inches in height and has 9 copper tubes providing 8 gaps. The copper tubes are 3/4 inch in diameter and 2 inches in length. The gaps are adjustable by moving the copper tubes and using a feeler gauge to set a total spark gap between 0 inches to about 0.5 inches. Currently, the spark gap is set to run on 7 gaps, each of which set to about 0.040 inches, providing a total gap of about 0.3 inches. Three mounts on the bottom of the spark gap provide a space for improved spark quenching: cool, fresh air enters the bottom of the spark gap while hot, ionized air exits the top of the spark gap. A fan should probably be attached to the spark gap for even better, stabilized quenching!!!

Bottle Capacitors: Nine quart-sized bottle capacitors; six installed on the Tesla coil and 3 spares. Each capacitor is a 1-quart beer bottle, made of clear glass. Aluminum tape forms a first electrode while an 8-inch, 1/4-20 brass rod forms a second interior electrode. Each brass rod passes through, and is bolted to the bottle's lid. A small hole in each bottle lid provides ventilation to avoid pressure build up and thus prevents capacitor explosion during extended operation. Polyethylene tape is wrapped around the center section of each bottle to prevent electrical arcing with a Nylon belt which secures the bottles in the tank. A wing nut attached to each brass rod facilitates easy installation/removal of wire connectors between the bottle capacitors, as well as to the primary coil. A 1/4-inch compression fitting and lock nut connect the bottle capacitors to the bottom end of the primary coil. Plexiglas sheets shield the bottle capacitors from the wood of the tank housing. A bottom Plexiglas sheet has two strips of aluminum tape upon which the six bottle capacitors are secured. The two strips of aluminum tape establish electrical communication between the bottle capacitors and the rest of the tank circuit.

Primary Coil: The primary coil is 15 turns of 1/4-inch copper tubing, supported by 4 PVC tubes that are 3/4 inch in diameter. About 1 inch above the primary coil is a ground rail which is connected to the RF ground of the secondary coil. The primary coil stands at about 8 3/4 inches in height; and with the ground rail, the primary coil stands at about 10.5 inches in height. As mentioned above, a 1/4-inch compression fitting and lock nut connect the bottom end of the primary coil to the bottle capacitors. The primary coil is sealed with Krylon Crystal Clear Liquid Plastic.

Secondary Circuit:

Secondary Coil: The secondary coil is 24 inches in length and 4.5 inches in diameter. This coil was machine wound on green PVC tube with enamel coated, 24 gauge wire. Epoxy was used to secure an end cap to each end the secondary coil. A 3/8-inch bolt-stock passes through, and is bolted to, each end cap. The bolt-stocks are each about 6 inches in length. The bottom bolt-stock passes through two 4.5-inch PVC end caps, which are used to raise the secondary coil up relative to the primary coil. Together, the two end caps raise the secondary coil up by about 4 inches. The secondary coil is sealed with Krylon Crystal Clear Liquid Plastic.

Top Terminal: The Top Terminal comprises two pie tins placed rim-to-rim, both of which bolted to the top bolt-stock of the secondary coil. The pie tins are easily removable/replaceable by unscrewing the bolts and lifting the pie tins off the bolt-stock.