Invention Grant
- Patent Title: Motor drive device
- Patent Title (中): 电机驱动装置
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Application No.: US13030334Application Date: 2011-02-18
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Publication No.: US08093846B2Publication Date: 2012-01-10
- Inventor: Tomofumi Mishima , Satoshi Miyajima
- Applicant: Tomofumi Mishima , Satoshi Miyajima
- Applicant Address: JP
- Assignee: Rohm Co., Ltd.
- Current Assignee: Rohm Co., Ltd.
- Current Assignee Address: JP
- Agency: Cantor Colburn LLP
- Priority: JP2005-245973 20050826
- Main IPC: H03K5/00
- IPC: H03K5/00

Abstract:
In the motor drive apparatus, a Hall element outputs a first sinusoidal signal and a second sinusoidal signal, of mutually opposite phases, in accordance with rotor position. A hysteresis comparator compares the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a rectangular wave signal. A pulse width modulation signal generation circuit detects timing at which phase switches, based on the first sinusoidal signal and the second sinusoidal signal outputted from the Hall element, and outputs a pulse width modulation signal in which duty ratio gradually changes, in a predetermined time-period in which the phase switches. A drive circuit combines the rectangular wave signal and the pulse width modulation signal by a logical operation, and drives the fan motor.
Public/Granted literature
- US20110139412A1 MOTOR DRIVE DEVICE Public/Granted day:2011-06-16
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