RF induction lamp with reduced electromagnetic interference
First Claim
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1. An induction radio frequency (RF) fluorescent lamp, comprising:
- a lamp envelope with a re-entrant cavity both covered on a partial vacuum side with phosphor and filled with a working gas mixture;
a tubular ferromagnetic core on a non-vacuum side of said re-entrant cavity, wherein one or more radial spacers support the tubular ferromagnetic core to be axial to the re-entrant cavity with a fixed air gap between them;
two windings on said tubular ferromagnetic core having a different number of turns, a first winding being an active winding having one end connected to an RF ballast and the other end connected to local ground and a second winding being a passive winding having one end grounded and the other end free.
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Abstract
An induction RF fluorescent lamp configuration provides reduced EMI, including a lamp envelope with a re-entrant cavity both covered on the partial vacuum side with phosphor and filled with a working gas mixture, a tubular ferromagnetic core on the non-vacuum side said re-entrant cavity wound directly on the said core with two windings having different numbers of turns, a first active winding having one end connected to an RF ballast and the other end connected to local ground, and a second passive winding having one end grounded and the other end free.
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Citations
6 Claims
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1. An induction radio frequency (RF) fluorescent lamp, comprising:
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a lamp envelope with a re-entrant cavity both covered on a partial vacuum side with phosphor and filled with a working gas mixture; a tubular ferromagnetic core on a non-vacuum side of said re-entrant cavity, wherein one or more radial spacers support the tubular ferromagnetic core to be axial to the re-entrant cavity with a fixed air gap between them; two windings on said tubular ferromagnetic core having a different number of turns, a first winding being an active winding having one end connected to an RF ballast and the other end connected to local ground and a second winding being a passive winding having one end grounded and the other end free. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification