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:
Dec. 30, 2003
Filed:
Jan. 03, 2003
Japan Servo Co., Ltd., Tokyo, JP;
Abstract
A stepping motor driver having current sensors that detect winding current values, an angle detection device that detects a rotational angle of a rotor, a first coordinate transformation device that transforms winding current values in a rotational coordinate system, an angle calculation device that calculates a command angle value. A third coordinate transformation device transforms the command current values in the rotational coordinate system according to the difference between the command angle value and the rotor angle value, a current control device that generates current control signals in the rotational coordinate system based on the differences between the command current values in the rotational coordinate system and the winding current values in the rotational coordinate system. A second coordinate transformation device transforms the current control signals in the rotational coordinate system into current control signals in a fixed coordinate system, and a current supply device that supplies currents to windings of the stepping motor.