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. 26, 2009
Filed:
Sep. 20, 2007
Masahiro Tsuchida, Okazaki, JP;
Daisuke Mizuno, Kariya, JP;
Masahiro Tsuchida, Okazaki, JP;
Daisuke Mizuno, Kariya, JP;
Denso Corporation, Kariya, JP;
Abstract
A motor controller includes an inverter circuit, a speed detector, an amplifier, a voltage detector, and an offset voltage addition circuit. The inverter circuit drives a motor based on a PWM signal. The speed detector generates an actual speed signal corresponding to an actual speed of the motor. The amplifier outputs a differential voltage by amplifying a difference between the actual speed signal and a target speed signal. The voltage detector outputs a switch signal for switching rotation direction of the motor. The switch signal has a first level, when the differential voltage is equal to or greater than a predetermined value. The switch signal has a second level, when the differential voltage is less than the predetermined value. The offset voltage addition circuit adds an offset voltage to the differential voltage according to the signal level of the switch signal.