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:
Apr. 17, 2001
Filed:
Dec. 16, 1999
Youichi Syukuri, Fukuoka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A rotor magnetic pole position detection device detects a zero-cross point in a induced voltage induced in a stationary winding under a PWM control, and is used in a DC brushless motor drive control apparatus to be driven in a sensorless mode. A detection circuit detects terminal voltages of a plurality of stationary windings. A reference voltage generation circuit generates a reference voltage. A comparison unit compares the terminal voltages with the reference voltage. A speed command voltage generation unit generates a PWM ON-width control signal. A PWM control signal generation unit generates a PWM control signal which has a duty ratio corresponding to the PWM ON-width control signal. A logical operating unit obtains a phase signal from an output signal of the comparison unit, and outputs an energization timing signal based on the phase signal and the PWM control signal. A driver circuit energizes the stationary windings based on the energization timing signal. The logical operating unit detects whether or not the induced voltage of each of the stationary windings is zero-crossed at a rising or falling edge of a triangle wave generation clock for generating the PWM control signal.