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:
Jul. 17, 2012
Filed:
Oct. 20, 2009
Katsuyoshi Nakada, Yawata, JP;
Tomoyuki Nakano, Sakai, JP;
Junichi Hasegawa, Kashiwara, JP;
Koji Watanabe, Yawata, JP;
Katsuyoshi Nakada, Yawata, JP;
Tomoyuki Nakano, Sakai, JP;
Junichi Hasegawa, Kashiwara, JP;
Koji Watanabe, Yawata, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An electronic ballast is provided for powering a high intensity discharge lamp. A voltage step-down circuit is arranged to reduce an input DC voltage. An inverter circuit includes at least one high frequency switching element is and arranged to convert the reduced voltage to a high frequency AC voltage. A resonant circuit receives the high frequency voltage and is further coupled to the discharge lamp. A voltage step-down control circuit controls the DC voltage output from the voltage step-down circuit. A driving circuit supplies a driving signal to the switching element of the inverter, and further adjusts a driving frequency of the driving signal, thereby controlling the high-frequency voltage. The high frequency voltage in a first operating mode is controlled to a low level wherein the lamp is prevented from starting. The high frequency voltage in a second operating mode is controlled to a high level wherein the discharge lamp can be started.