One of Nikola Tesla's most famous inventions is the Tesla Coil. It is essentially a high-frequency air-core transformer that takes the output from a 120vAC to a several kilovolt transformer & driver circuit, and steps the voltage up to an extremely high amount.
A plasma globe consists of a clear glass orb filled with a mixture of various gases most commonly helium and neon, but sometimes also xenon and krypton at low pressure (below 0.01 atmosphere) and driven by high-frequency alternating current at approximately 35 kHz, 2 to 5 kV, generated by a high-voltage transformer.
A much smaller orb in its center serves as an electrode. Plasma filaments extend from the inner electrode to the outer glass insulator, giving the appearance of multiple constant beams of colored light. The beams initially follow the electric field lines of the dipole but move upwards due to convection.
The radio frequency field produced by plasma lamps may interfere with the normal operation of the touchpads used on laptop computers, digital audio players, cell phones, and other similar devices. Large plasma globes can radiate sufficient RFI to interfere with cordless telephones and Wi-Fi devices several feet away. Also, when a metallic object (such as a coin) is placed on the surface of a plasma lamp's glass, a dangerous shock and burn can result; it is very easy for electricity to ground from the lamp if the metal comes in contact or proximity with certain materials, including human tissue.