Conventional coil figures and photos

Figure 1. 
A schematic diagram with all the required parts for a good Tesla coil – “good” meaning a coil which will produce impressive sparks, but which stands a reasonable chance of surviving the incredible electrical stresses which are generated by its operation.

Figure 2.  
Several neon or luminous tube transformers, and a furnace ignition transformer.  All use a similar method of construction, and are filled with tar or similar potting insulation.

Figure 3.  
Shown are a 2 kVA and a 5 kVA potential transformer.  They are compared in size to a typical 360 VA neon transformer.

Figure 4.  
A variety of distribution transformers, or “pole pigs” as they are known.

Figure 5.  
Some heater resistive elements used as current limiting ballasts for large Tesla coils.  Note the adjustable slide tap on the nichrome wire element.

Figure 6.   
Typical methods of connecting resistive and inductive ballasts to limit current to potential and distribution transformers.

Figure 7.  
Shown are several styles of variacs.  Note the dual and triple transformers on one common shaft.  Dual 120-volt transformers can be wired for 220 volts.  The triple transformers are originally designed to be used with 3 phase, 220-volt power, and can still be salvaged for single-phase use.  

Figure 8.  
Methods of wiring variacs and ballasts to control current to transformers.  Note the method of connecting two 120-volt variacs to control 220 volts.

Figure 9.  
Several line filters, ranging is size from 5 amps to 50 amps.

Figure 10.  
A safety spark gap constructed of 1-inch ball bearings mounted on ceramic insulators and connected to the transformer.  Note that the center ball is grounded.

Figure 11.  
Shown are typical bypass capacitors.  These are small ceramic and mica “door knob” capacitors.  

Figure 12.  
4 inch diameter, 6 inch long air core choke wound with 28 gauge enamel wire, and a 2 inch ferrite core choke, also wound with 28 gauge wire.

Figure 13a, b, c.  
Typical transformer protection circuits.  The third circuit is a “pi” circuit and is very effective.

Figure  14.
The damped wave observed in the primary circuit.

Figure 15.
A Lexan disk is shown with electrodes.  The hole in the center of the disk mounts onto the end of the drive motor shaft.

Figure 16.
Rotary spark gap, showing the Lexan disk, electrodes, and motor.

Figure 17.
A Helical primary, a flat pancake primary coil, and an inclined pancake primary.

Figure 18.
Typical secondary coil.

Figure 19.
Several capacitors suitable for Tesla coil use.  They are shown in the preferred order, best to worst. Polypropylene commercial cap, homemade polyethylene capacitor, mica transmitting cap, ceramic doorknob, glass plate capacitor, beer bottle capacitor. 

Figure 20.
A homemade polyethylene capacitor, prior to rolling into a cylinder.

Figure 21.
Safety gap installed on a commercial capacitor.

Figure 22.
Safety gap across transformers

Figure 23.
Some toroids made out different materials.

Figure 24.
Figure showing toroid mounted above top of coil, and spiraling wire attachment.

Figure 25.
Do not connect the secondary to the wall outlet ground!

Figure 26.
The Tesla coil in operation, producing sparks in excess of four feet in length

Figure 27.
The box frame and location of components

Figure 28.
The layout of the disk.

Figure 29.
Double-sticky tape layout of primary

Figure 30.
Hole positions in plywood.

Figure 31.
Hand-crank operated coil winding jig.

Figure 32.
Disks with centering pins

Figure 33.
Sewer pipe toroid details

Figure 34.
Flexi-duct toroid details

Figure 35.
Capacitor shelf and strap.

Figure 36.
Initial placement of fiberglass rods for static gap.

Figure 37.
Placement of double-sided sticky foam tape on static gap.

Figure 38.
Layout of rotary disk

Figure 39.
Simple controllers for AC/DC motors, and a DC power supply for a DC motor.

Figure 40.
Method of truing up edge of rotary disk.

Figure 41.
Detail of flying electrode

Figure 42.
Detail of stationary electrodes.

Figure 43.
Complete rotary spark gap.

Figure 44.
Neon transformer controller schematic.
 Note that the ground on the line filter connects to the ground wire on the three-wire electrical outlet ground.  The AC voltmeter and amp meters allow you to measure input power.  The light dimmer control varies the speed of the rotary spark gap motor, while the variac will control power into the transformers.  If your rotary gap motor uses a DC motor and power supply, you will have to replace the light dimmer control with a small variac. 

Figure 45.
Controller parts layout

Figure 46.
Potential transformer controller schematic

Figure 47.
Adjustable ballast which uses nichrome wire.

Figure 48.
Stack of neon transformers

Figure 49.
Good triangular grounding system

Figure 50.
Controller, Tesla coil, and the cable locations

Magnifier figures and photos

Figure 1. 
Schematic diagram with all the required parts for a Tesla Magnifier.  Many of the components used in a Magnifier are the same as used in a conventional coil, but much of the coil and spark gap design is different.

Figure 2.  
Shown are a 2 kVA and a 5 kVA potential transformer.  They are compared in size to a typical 360 VA neon transformer.

Figure 3.  
A variety of distribution transformers, or “pole pigs” as they are known.

Figure 4..  
Some heater resistive elements used as current limiting ballasts for large Tesla coils.

Figure 5.   
Typical methods of connecting resistive and inductive ballasts to limit current to potential and distribution transformers.

Figure 6.  
Shown are several styles of variacs.  Note the dual and triple transformers on one common shaft.  Dual 120-volt transformers can be wired for 240 volts.  The triple transformers are originally designed to be used with 3 phase, 240-volt power, and can still be salvaged for single-phase use.  

Figure 7.  
Methods of wiring variacs and ballasts to control current to transformers.  Note the method of connecting two 120-volt variacs to control 240 volts.

Figure 8.  
Several line filters, ranging in size from 5 amps to 50 amps.

Figure 9.  
A safety spark gap constructed of 1-inch ball bearings mounted on ceramic insulators and connected to the transformer.  Note that the center ball is grounded.

Figure 10.  
Shown are typical bypass capacitors.  These are small ceramic and mica “door knob” capacitors.  

Figure 11.  
4 inch diameter, 6 inch long air core choke wound with 28 gauge enamel wire, and a 2 inch ferrite core choke, also wound with 28 gauge wire.

Figure 12.  
Typical transformer protection circuits.  The third circuit is a “pi” circuit and is very effective.

Figure 13.
The damped wave observed in the primary circuit.

Figure 14.
A Lexan disk is shown with electrodes.  The hole in the center of the disk mounts onto the end of the drive motor shaft.

Figure 15.
Rotary spark gap, showing the Lexan disk, electrodes, and motor.

Figure 16.
The Helical primary.  Note the polyethylene insulation between the primary and secondary coils. 

Figure 17.
Secondary coil before insulating.

Figure 18.
Two capacitors suitable for Tesla Magnifier coil use.  They are shown in the preferred order, best to worst. Polypropylene commercial cap, homemade polyethylene capacitor

Figure 19.
A homemade polyethylene capacitor, prior to rolling into a cylinder.

Figure 20.
Safety gap installed on a commercial capacitor.

Figure 21.
Safety gap across transformers

Figure 22.
Some toroids made out different materials.

Figure 23.
Figure showing toroids mounted above top of Extra coil

Figure 24.
Do not connect the secondary to the wall outlet ground!

Figure 25.
Good triangular grounding system

Figure 26.
The Tesla magnifier coil in operation, producing sparks in excess of 10 feet in length

Figure 27.
The box frame and location of components

Figure 28.
Bolt hole for secondary 

Figure 29.
Two-by-four support and winding jig hole placement.

Figure 30.
Location of secondary ground hole.

Figure 31.
Two-by-four support and winding jig hole placement.

Figure 32.
Hand-crank operated coil winding jig.

Figure 33.
Ground plate details

Figure 34.
Details of the Extra coil, with the three toroid centering pins.

Figure 35.
Toroid details

Figure 36.
Initial placement of fiberglass rods for static gap.

Figure 37.
Placement of double-sided sticky foam tape on static gap.

Figure 38.
Layout of rotary disk

Figure 39.
Simple controllers for AC/DC motors, and a DC power supply for a DC motor.

Figure 40.
Method of truing up edge of rotary disk.

Figure 41.
Detail of flying electrode

Figure 42.
Detail of stationary electrodes.

Figure 43.
Complete rotary spark gap.

Figure 44.
Controller parts layout

Figure 45.
Potential transformer controller schematic

Figure 46.
An adjustable ballast which uses nichrome wire.

Figure 47.
Controller, Tesla coil, and the cable locations