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:
Nov. 05, 2002
Filed:
Jun. 01, 2001
Sony Corporation, , JP;
Abstract
A motor control apparatus according to the present invention comprises: a servo circuit for outputting a pulse width modulation signal; a low-pass filter for receiving the pulse width modulation signal outputted by the servo circuit as an input; and a driver circuit for receiving an output voltage of the low-pass filter as an input and thereby driving a brushless sensorless motor; wherein the servo circuit controls pulse width of the pulse width modulation signal so as to maintain rotational speed of the motor at a target rotational speed on the basis of an FG pulse signal outputted by the motor, the FG pulse signal representing the rotational speed of the motor by frequency. The motor control apparatus further includes a rotational speed changing means, the rotational speed changing means changing the rotational speed of the motor by gradually varying a voltage outputted by the driver circuit from a current voltage to a target voltage on input of a control start signal.