The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 15, 2009
Filed:
Sep. 25, 2007
Nancy H. Chen, North Andover, MA (US);
Joseph A. Olsen, Gloucester, MA (US);
Nancy H. Chen, North Andover, MA (US);
Joseph A. Olsen, Gloucester, MA (US);
OSRAM SYLVANIA Inc., Danvers, MA (US);
Abstract
A method of controlling run-up of a metal halide lamp that has a nominal (full) light output during steady state operation and that has a current limit I, includes, during run-up of the metal halide lamp to steady state operation, evaluating requested power Pand requested current Ito operate the lamp at the nominal light output Lduring the run-up, supplying Ito operate the lamp so long as I≧Iand supplying Pto operate the lamp when I<I, and modulating power P supplied to the lamp. The power modulation is preferably at an acoustic resonance frequency of the lamp, such as the first azimuthal resonance mode of the lamp. Power modulation may include sweeping a sine wave ripple on top of an input voltage waveform, wherein a frequency range of the sine wave ripple includes an acoustic resonance frequency.