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. 08, 1990
Filed:
Dec. 22, 1988
Yuzo Miyazawa, Yamatokoriyama, JP;
Koichi Nakamura, Yamatokoriyama, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A rotor movement warning device for use in a stepper motor has a stator provided with a plurality of windings and a rotor rotatably provided in associated with said stator. The rotor movement warning device includes a power source, a plurality of switching transistors provided in association with the plurality of windings, respectively, for controlling power supply from the power source to the windings, and a driving pulse producer for producing driving pulses to the plurality of switching transistors for effecting the rotation of the rotor. Further provided are detector for detecting, when the rotor stops, at least one switching transistor which is provided with the last driving pulse, and low frequency signal producer for producing low frequency signals which are applied to the switching transistor detected by the detector.