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:
Aug. 07, 2018
Filed:
Jun. 26, 2014
Panasonic Intellectual Property Management Co., Ltd., Osaka, JP;
Tsuraki Nakajima, Aichi, JP;
Harumoto Itou, Aichi, JP;
Masahiro Yamaguchi, Aichi, JP;
Shingo Takenawa, Aichi, JP;
Kazuki Doumoto, Aichi, JP;
Teikyo Ueno, Aichi, JP;
Abstract
Between the lower stage in respective phases of inverter circuit and the negative potential side, shunt resistors are inserted for respective phases. The potential differences across shunt resistors occurring by current flowing through shunt resistors are amplified by amplifier unit. From the output of amplifier unit, current detecting unit detects current of each phase flowing through motor formed by a sensorless brushless DC motor. Rotation detecting unit calculates the rotation speed and position of motor based on the current detected by current detecting unit. This structure makes it possible to directly detect solely the current flowing through the windings of motor. Therefore, it becomes possible to accurately detect the current of the motor windings, and the ventilation device can maintain the ventilation air volume from a small air volume to a large air volume always at a constant value.