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:
Feb. 04, 2003
Filed:
Apr. 26, 2001
Haruo Moriguchi, Itami, JP;
Kenzo Danjo, Kyoto-fu, JP;
Takashi Tsujii, Hirakata, JP;
Masataka Nishimura, Izumi, JP;
Sansha Electric Manufacturing Company, Limited, Osaka, JP;
Abstract
A power supply apparatus useful for starting and driving a discharge lamp includes a DC-to-DC converter for converting a DC signal from a DC power supply to a second DC signal having a predetermined magnitude which is supplied to the lamp. A current detector develops a DC current representative signal representing DC current supplied to the lamp from the DC-to-DC converter. A combination of the current detector a DC voltage detector and a multiplier develops a DC power representative signal representing DC power supplied from the DC-to-DC converter to the lamp. An error amplifier develops a DC current error signal representing the difference between the DC current representative signal and a predetermined DC current reference signal. An error amplifier develops a DC power error signal representing the difference between the DC power representative signal and a predetermined power reference signal. For a predetermined time period following the start of operation of the power supply apparatus, a combination of a delay circuit a comparator and a clamping diode clamps the DC power error signal so that only the DC current error signal can be outputted. A driver unit controls the DC-to-DC converter in such a manner as to make the DC current error signal zero.