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:
Sep. 28, 1999
Filed:
Nov. 19, 1997
Akihiko Kanouda, Hitachinaka, JP;
Yoshimi Sakurai, Hitachiota, JP;
Kenji Kubo, Hitachi, JP;
Hideyasu Umetsu, Hitachi, JP;
Hideaki Kunisada, Hitachi, JP;
Keizo Shimada, Juo-machi, JP;
Takayasu Nakane, Kitaibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Engineering Co., Ltd., Ibaraki, JP;
Abstract
A sine wave input converter provided with a phase sequence computation unit which inputs two line voltages or two phase voltages of the three phase ac power supply, computes the phase of a sine wave voltage of one of these two inputs, and determines on the basis of computation using these two input voltages and the phase whether the phase sequence is positive or antiphase, which is determined depending on whether the result of computation assumes a constant value, or becomes a sine wave oscillating between positive and negative values. Power supply interruption can be determined from the same computation result.