David Rieben’s

GREEN MONSTER TESLA COIL SYSTEM

 

About the Author  

 

The secondary coil consists of a 12 1/2" OD x 54" long gray PVC duct pipe wound w/ 1260 turns of green enameled #19 AWG magnet wire for a total winding length of 49 1/2". The primary coil consists of 12 turns of 5/8" OD soft copper tubing wound in a flat Archemedian spiral w/ approximately 1/2" spacing between adjacent turns with the innermost (1st) primary turn at about 15" in diameter and the outermost (12th) primary turn at about 40" in diameter. Primary taps out at approximately 10 turns for optimal tuning.

The stationary spark gap is in series with the rotary spark gap for assistance of heat dissipation. This is an RQ (Richard Quick) style gap consisting of (4) 2" diameter x 5" long copper pipe segments mounted parallel to each other with approximately 1 to 2 mm of spacing between each of the 3 resultant gaps.

RF grounding is (3) 8 ft long x 5/8" diame- ter copper-clad grounding rods driven to all but a few inches into the ground right next to the driveway and spaced 4 ft apart. All three rods are inter-connected just below ground level with a solid #4 AWG copper grounding wire. The # 2-0 AWG dedicated RF ground lead from the coil base is connected to the middle ground rod of the three.

 

Closeup view of the 18 kv distribution arrester across the HV output bushings of the 15 kVA pole transformer to act as a shunt for the HV kicback transients of the primary tank circuit

Primary strike ring (upper copper tube), primary coil (lower copper tube), 0.1 uFd, 50 kV Hipotronics pulse capacitor (blue-green rectangular box) and stationary gap cooling fan (below the pulse capacitor) note the primary coil tap just above the pulse capacitor

 

View of the Primary coil.

 

Another view of the primary coil.

 

Another view of the primary tank circuit. note the strike ring termination to the dedicated RF ground

 

Strike ring, primary coil, and dedicated RF ground hookup

View of central primary coil hookup and dedicated RF ground. note the rotary spark gap DC drive motor and filtering capacitors in the lower left of photo

 

Rotary spark gap components, note the red fiberglass disc and brass square stock supports for the stationary tungsten carbide electrodes (8) 3/8" x 2 1/2" long tungsten carbide rotary electrodes on the 1/2" x 11 1/4" diameter red fiberglass disc. The (2) stationary electrodes are 1/2" x 3" long. Rotary flying electrodes and stationary electrodes are set to minimum practical clearance without danger of electrode collision (~ 1/16" clearance)

 

Another view of the primary circuit, note the 2-0 AWG welding cable leads for the heavy currents of the pulse capacitor discharges

 

14,400 volt/240 volt, 15 kVA pole-mount distribution transformer aka - (pole pig) for the high voltage to charge the primary pulse capacitor

 

Control panel assembly

Close-up view of the control panel switching and metering

 

Another view of the control panel face, note the control knob for the variac control of the rotary spark gap drive motor at the lower center of the photo

 

View of the main pole pig power control variac turn knob on the top of the control panel. the main power control variacs are (2) paralleled 240/0-280 volt @ 28 amp 1256D Powerstats for a total continuous control rating of up to 280 volts @ 56 amps

 

Here is a view of the insides of the control panel from the back. The twin 1256D Powerstat can be seen on the top and the homemade ballast tank can be seen directly below the twin Powerstats.

 

Here is a view of the homemade ballast from the back of the control panel. The ballast was constructed from the "guts" of a Lincoln 225 amp AC arc welder with the with the 2 highest amperage setting taps (200 and 225 amps) paralleled and shorted together. The tank originally housed a high voltage divider from from an x-ray machine (thanks Carl Litton). Once the welder transformer/inductor was mounted inside the tank, the tank was filled with Shell Diala AX transformer oil.

 

Overview of the entire Tesla coil tank circuit assembly. note the 12" minor diameter x 56" major diameter toroid terminal capacitance atop the secondary coil

 

Green Monster hurling 10 ft+ sparks all over the driveway and front yard to the horror of the neighbors (next 4 shots)

 

 

 

 

  To improve the output, 60 Amp service was upgraded to 100 Amp service. A lower reactance dry ballast was substituted for the welder under oil pictured above. The new ballast is a 230 lb. Toshiba isolation transformer (left).

Here is a pic of the Klockner & Moeller 210 amp rated, 3-pole motor starter contactor that I'm using to energize the pole transformer for my coil.

  Here is a recent run with a little over 60% increase in input power.

 

 

My 14 year old Ben and myself with Green Monster