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:
Feb. 01, 2005
Filed:
Mar. 18, 2003
Yoshifumi Kuwano, Kiryu, JP;
Akio Takemori, Kiryu, JP;
Yasuo Matsuda, Kiryu, JP;
Yoshihiro Okumatsu, Miyazaki, JP;
Atsuo Kawamura, Yokohama, JP;
Yoshifumi Kuwano, Kiryu, JP;
Akio Takemori, Kiryu, JP;
Yasuo Matsuda, Kiryu, JP;
Yoshihiro Okumatsu, Miyazaki, JP;
Atsuo Kawamura, Yokohama, JP;
Japan Servo Co., Ltd., Tokyo, JP;
Abstract
The stepping motor driver comprises an inverter for feeding stepped currents to windings of a stepping motor, a position detector for obtaining a detected angle of a rotor of the stepping motor and a current controller for controlling the inverter. In a d-q rotational coordinate system in which the d-axis is in the direction of the magnetic flux of the rotor and the q-axis is in the direction perpendicular to the d-axis, an excitation angle for a winding is determined from a d-axis component and a q-axis component of a command current to the winding, a lead angle control signal is computed from the excitation angle, and a phase of an applied voltage to the stepping motor is controlled using the lead angle control signal.