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:
Jan. 04, 2011
Filed:
Jun. 30, 2008
Andrew Johnsen, Danvers, MA (US);
Phillip Whitt, Salem, MA (US);
Andrew Johnsen, Danvers, MA (US);
Phillip Whitt, Salem, MA (US);
Osram Sylvania Inc., Danvers, MA (US);
Abstract
A high frequency ballast for a metal halide lamp comprises a controller, a switch, and an oscillator. The controller selectively enables and disables the oscillator via the switch to ignite the lamp. The switch selectively alters an inductance of the inductor to switch between a first frequency of the oscillator and a second frequency of the oscillator different than the first. The controller monitors a current of a power supply loop of the oscillator and a voltage of the oscillator and determines a duty cycle as a function of the monitored voltage and current. The duty cycle is indicative of the percentage of time that the oscillator is to operate at the first frequency versus the second frequency.