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:
Apr. 29, 2003
Filed:
Aug. 07, 2002
Seiji Ishida, Hitachi, JP;
Toshiaki Okuyama, Tokai, JP;
Tetsuo Kojima, Hitachinaka, JP;
Kiyoshi Nakata, Iwase, JP;
Akira Horie, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The voltage applied to a power converter is detected by a voltage detector, a function generator produces a voltage proportional to this detected voltage, and a high-pass filter detects an AC component superimposed on the voltage. An adder adds a bias voltage to this AC component, and an adder adds the output from the adder and the output from the function generator. The output from the adder is compared with a triangular wave produced from a rectangular wave generator, and a switching element is controlled to make switching operation according to the compared result. When a DC current is decreased by the AC component, a resistance current Ib is increased so that the AC components superimposed on the current and resistance current can be cancelled out.