US 7,746,001 B2Granted

Plasma generator having a power supply with multiple leakage flux coupled transformers

AssigneePlasma Technics, Inc.

InventorRalph M. Francis, Jr.

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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.

Claims18

Dependent claims

A plasma generator comprising:

a plurality of plasma discharge cells in which a gas is excited to produce a plasma;
a signal generator for producing an excitation signal having a high frequency;
and
a plurality of transformers, each having a separate ferromagnetic core, a primary coil wound on the core at a first location and connected to the signal generator, and a secondary coil wound on the core at a second location and connected to one of the plurality of plasma discharge cells thereby forming a resonant circuit having a resonant frequency, the core having a flux leakage that produces a stray magnetic field outside the core, the plurality of transformers placed in close proximity to each other so that the stray magnetic field from each transformer is coupled to at least one other transformer, thereby altering the resonant frequency of at least one resonant circuit wherein all the resonant circuits resonate at substantially an identical frequency.

1 more element

A plasma generator comprising:

a plurality of plasma discharge cells in which a gas is excited to produce a plasma and having electrodes between which a field is generated for exciting the gas;
an inverter for producing an excitation signal having a high frequency;
and
a plurality of transformers, each having a separate ferromagnetic core with opposing first and second side legs, a first cross leg providing a flux path between one end of each of the first and second side legs, and a second cross leg providing another flux path between another end of each of the first and second side legs, a primary coil wound around the first side leg and connected to the inverter, and a secondary coil wound around the second side leg and connected to one of the plurality of plasma discharge cells, thereby forming a resonant circuit having a resonant frequency, the core having at least one gap causing a stray magnetic field to be created outside the core, the plurality of transformers placed in close proximity to one other so that each transformer is coupled to the stray magnetic field from at least one other transformer, thereby altering the resonant frequency of at least one resonant circuit wherein all the resonant circuits resonate at substantially an identical frequency.

1 more element

Dependencies are inferred from the claim text.