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. 03, 2007
Filed:
Nov. 06, 2003
Takuya Ishii, Osaka, JP;
Masaharu Ikeda, Yokohama, JP;
Hiroki Akashi, Hirakata, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A power amplifying apparatus which is of a switching type and capable of efficiently amplifying a power of an input AC signal such as an acoustic signal, includes a first switch circuit () and a second switch circuit () to which a power supply voltage Vc is applied, an inductor () and a load () which are connected between the switch circuits, and a control circuit () which receives an input AC signal Vi, sets a predetermined ratio of ON/OFF periods, and drives the switch circuits. The control circuit () includes an arithmetic circuit () which multiplies a modulation sensitivity (for example, an amplitude of a triangular wave voltage used for generation of a pulse signal for driving a switch circuit) by a ratio (Vc/Ec) of the power supply voltage Vc and a DC component Ec thereof. This configuration can compensate for distortion caused by a ripple variation of the power supply voltage due to regenerated power or the like, and enable a gain control by the power supply voltage.