Abstract: A plasma generating apparatus includes a plurality of discharge cells in which a gas is excited by a high frequency excitation signal produced at an inverter. Each of a plurality of transformers couples the excitation signal from the inverter to one of the discharge cells, thereby forming a separate resonant circuit that has a resonant frequency. A gap in the transformer core creates a stray magnetic field outside the transformer. The plurality of transformers are in close proximity to each other so that the stray magnetic field from one transformer is coupled to at least one other transformer. Coupling the stray magnetic fields between transformers results in each resonant circuit resonating at the same frequency.

Abstract: A non-perforated metal tube with open opposite ends extends coaxially around a plasma discharge tube that projects beyond both ends of the metal tube. The plasma tube contains an ionizable gas and an electrode. The ends of both tubes engage two end cap assemblies which maintain the tubes in a coaxial, uniformly spaced relationship. Both end cap assemblies have a tubular coupling that fits around a flared end of the metal tube and have a mechanism for supporting the glass tube. Passages are provided in the end cap assemblies for gas to enter and exit. A plasma is established in the plasma discharge tube by applying an excitation potential between the electrode and the metal tube.

Abstract: A transformer of the type used to produce high voltage for an electrostatic field apparatus has a hermetically sealed container. The container encloses a coil assembly having primary and secondary coils wound on a common core. Electrical terminals extend outward from the container and are connected to the coils. The interior volume of the container is completely filled with a thermally conductive, electrically non-conducting fluid. The internal pressure of the transformer is less than one atmosphere at 22.degree. C. The transformer can be operated in any mounting orientation of its rated power. A method of manufacturing the transformer is described by which gases are removed from the container so that it can be completely filled with the fluid.