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:
Feb. 20, 2001
Filed:
Mar. 22, 1999
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
H02P 6/18 ; H02P 6/02 ;
U.S. Cl.
CPC ...
H02P 6/18 ; H02P 6/02 ;
Abstract
A phase signal generation circuit is constituted by using a comparison circuit,a delay circuit,a gate signal preparation circuit,and a selection holding circuit,A phase signal generated in the phase signal generation circuit,is pattern recognized in a control circuit,and a position of a rotor is detected and a PWM control area, PAM control, and a change-over PWM/PAM is carried out. The rotor position detection accuracy can be heightened and a wide control. range can be obtained.