Dr. MegaVolt’s Tesla Coils
The large Tesla Coil used for Dr. MegaVolt shows is 8.5 feet tall and draws approximately 35,000 watts of power from a 240 volt power outlet, about as much power as a small house. The discharges from the top terminal of the coil have been measured at 15 feet point to point. The estimated output voltage is just shy of 1 million volts. I built this coil with Paul O’ Leary of San Francisco over an 8 month period in 1991-92 while we were students at UC Berkeley. A large part of the design of this coil was furnished by Greg Leyh, the world’s foremost expert on the design of very large Tesla Coils. This coil system packs into a number of wood and plastic crates and can be shipped anywhere by air or motor freight. It is designed to fit on to a standard cargo plane pallet.
The system underwent a very extensive upgrade in the Fall of 2020. It was a great time to work on it, since there were no live shows happening during COVID-19. The control panel received new equipment, notably a current meter, a vibrating-reed mains frequency meter and a mechanical elapsed time meter that keeps track of how long the high voltage is energized:
The base of the Tesla Coil was upgraded as well. I bought a new motor to spin the spark gap, and added a ground bar. The original baseplate was made of acrylic and it had cracked at one corner, so I replaced it with 1″ thick subfloor plywood that will be much more resistant to damage from forklifting or rolling the base off ramps on moving vans.
Medium Tesla Coil: The medium Tesla Coil is a tabletop unit built in 1992 for a Halloween show. It plugs into a standard wall outlet, draws about as much power as a hair dryer, and produces discharges that are about 15 inches long. This coil is all self contained in a single unit, making it very easy to transport and set up. Dr. MegaVolt shows that utilize just this coil and the backpack coil are an economical alternative to shows that use the big Tesla Coil. The tabletop unit has its own dedicated shipping case and can be shipped anywhere in the world with ease.
The Backpack is a 225 Watt Battery-powered Tesla Coil system that is worn like a backpack. It was definitely inspired by the Proton Packs in Ghostbusters! I built it in March of 1999 for Burning Man. The Tesla Coil is mounted on the end of a rigid sleeve that fits over the operator’s right arm. It is capable of generating 4″ arcs and lighting up fluorescent light bulbs from a meter away. The Backpack Coil began as a helmet-mounted Tesla Coil invented by Greg Solberg, Brent Summers and myself during the spring of 1999. The Backpack Coil will run for many hours on a single charge. The battery is a 17 A-H lead-acid battery like the ones used for backup power in home alarm systems. I could get equivalent battery capacity from nickel-metal hydride batteries at a considerable savings in weight, but the lead battery is inexpensive and very durable. The transformer is a 200 watt neon sign unit that puts out 9kVAC. The spark gap unit inside is made of stainless steel shanks with tungsten buttons silver soldered on the ends. People always ask me: Does it hurt to get shocked by the Backpack? The answer is, yes it hurts, but it seems to be quite harmless. I have been shocked by it hundreds of times with no ill effect!