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:
Jan. 28, 2003
Filed:
Jul. 11, 2001
Hideo Matsushiro, Kusatsu, JP;
Keizo Matsui, Otsu, JP;
Kazushige Narazaki, Katano, JP;
Toru Tazawa, Ibaraki, JP;
Matsushita Electric Industrial Co., Ltd., Kadoma, JP;
Abstract
The invention provides an motor drive apparatus comprising a detector for detecting a terminal voltage in a non-energized phase and a detector for detecting a DC voltage applied to the main line of an inverter. The rotation of the brushless motor is controlled by specifying the inverter circulating current period from the terminal voltage and the DC voltage and calculating the magnetic pole position of the rotor from the terminal voltage after the end of the inverter circulating current period and a waveform of the terminal voltage predetermined from the characteristics of the brushless motor. As a result, the brushless motor can be rotated stably throughout a wide revolution range from low to high speeds.