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:
Nov. 25, 2003
Filed:
Jul. 18, 2002
Applicant:
Inventor:
Tokihiko Sawashi, Tokyo, JP;
Assignee:
Sony Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03F 3/217 ;
U.S. Cl.
CPC ...
H03F 3/217 ;
Abstract
A power amplifier apparatus includes a pair of power amplifiers for performing switching-type power amplification, a transformer, and a capacitor. The transformer is formed of a pair of coils that are connected in series between the corresponding output terminals of the pair of power amplifiers and the corresponding terminals of a speaker. The capacitor is connected in parallel with the output terminals of the pair of coils. With this configuration, a mutual inductance and a leakage inductance are generated in the coils. As a result, 180° out-of-phase and in-phase noise components contained in an output of the power amplifier apparatus can be eliminated.