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:
Jun. 26, 2012
Filed:
Nov. 25, 2009
Katsuyoshi Nakada, Kyoto, JP;
Tomoyuki Nakano, Sakai, JP;
Junichi Hasegawa, Osaka, JP;
Koji Watanabe, Kyoto, JP;
Katsuyoshi Nakada, Kyoto, JP;
Tomoyuki Nakano, Sakai, JP;
Junichi Hasegawa, Osaka, JP;
Koji Watanabe, Kyoto, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A lamp ballast is provided requiring less size and cost for powering a discharge lamp. An inverter circuit converts a DC voltage from a DC power source into a voltage having a determined frequency, and supplies the converted voltage to the discharge lamp inserted between a pair of output ends of the inverter. A resonant circuit includes an auto-transformer and a resonant capacitor, and supplies an output voltage corresponding to a frequency of the rectangular wave voltage of the power supply circuit to the discharge lamp. A voltage detection circuit detects an output voltage of the resonant circuit based on a potential of the resonant capacitor. A control circuit has a startup control mode to set the frequency of the rectangular wave voltage based on the detected voltage from the voltage detection circuit, wherein the output voltage of the resonant circuit exceeds a starting voltage of the discharge lamp.