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. 15, 2012
Filed:
May. 03, 2010
Yoshihiro Niwa, Gifu, JP;
Kazumasa Takai, Kagamigahara, JP;
Toshiyuki Shutoku, Tsushima, JP;
Takeshi Naganuma, Inazawa, JP;
Tomofumi Watanabe, Gifu, JP;
Yoshihiro Niwa, Gifu, JP;
Kazumasa Takai, Kagamigahara, JP;
Toshiyuki Shutoku, Tsushima, JP;
Takeshi Naganuma, Inazawa, JP;
Tomofumi Watanabe, Gifu, JP;
Sanyo Semiconductror Co., Ltd., Gunma, JP;
Semiconductor Components Industries, LLC, Phoenix, AZ (US);
Abstract
A stepping motor includes two coils and has supply currents to the two coils with different phases so that a rotor is rotated by the two coils. During a period where one coil is in a high impedance state, an induced voltage generated at that coil is detected. An output control circuit controls the magnitude of motor drive current supplied to the two coils in accordance with the detected induced voltage state. Then, prior to entering the high impedance state from the drive state, a short-circuit period is provided for short circuiting both terminals of the coil.