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:
May. 03, 2011
Filed:
Feb. 17, 2010
Tatsumi Yamauchi, Hitachiota, JP;
Hiroyuki Shoji, Hitachi, JP;
Seigou Yukutake, Hitachinaka, JP;
Toshikazu Okubo, Hitachinaka, JP;
Tatsumi Yamauchi, Hitachiota, JP;
Hiroyuki Shoji, Hitachi, JP;
Seigou Yukutake, Hitachinaka, JP;
Toshikazu Okubo, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A bi-directional DC-DC converter uses a transformer for both step-down and step-up operations. A switching frequency for operating a switching device is set separately for the step-down and step-up operations. When, for example, the switching frequency during the step-up operation is lower than the switching frequency during the step-down operation, the range in which the duty ratio in PWM control can be controlled is widened, compensating for step-up ratio insufficiency. Conversely, step-down ratio insufficiency is compensated for by making the switching frequency during the step-down operation lower than the switching frequency during the step-up operation.