摘要 |
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, thereby compensating for manufacturing tolerances and changes in operating conditions of the discharge cells that otherwise affect the resonant frequency of a given circuit.
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