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. 05, 2019
Filed:
Dec. 15, 2016
Rohm Co., Ltd., Ukyo-Ku, Kyoto, JP;
Takashi Yoshiya, Kyoto, JP;
Kyoji Marumoto, Kyoto, JP;
ROHM CO., LTD., Kyoto, JP;
Abstract
When a motor is started up, an initial position detection circuit detects the initial position of a rotor using an inductive sensing method. An automatic parameter generating circuit determines a parameter to be used by the initial position detection circuit. The automatic parameter generating circuit measures: (i) a first time period τrequired for a coil current to reach a threshold after a first polarity voltage is applied across an electrode pair of the motor; and (ii) a second time period τrequired for the coil current to reach a threshold after a second polarity voltage is applied across the electrode pair, for each threshold value, while the threshold value used in the measurement is changed. The threshold that provides a maximum difference between the first time period τand the second time period τis held as the parameter to be used by the initial position detection circuit.