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. 20, 1997
Filed:
Apr. 19, 1995
Akira Minami, Kawasaki, JP;
Fujitsu Limited, , JP;
Abstract
A PWM pulse of a duty ratio according to a current instruction value D of a servo control section is outputted from a pulse width modulating section to a driving section, thereby current driving a load. In a calibrating process, a calibration processing section outputs a reference current instruction value Dr corresponding to a reference load current Ir and measures a drive current Is of a load. When the measurement current Is doesn't coincide with the reference load current Ir, the current instruction value is adjusted, a current instruction value Ds of the measurement current Is which coincides with the reference load current Ir is obtained, and a correction coefficient K=Ds/Dr of the current instruction value is decided. A correcting section corrects the current instruction value D which is outputted from a control section by the correction coefficient K obtained by the calibrating section and outputs to the pulse width modulating section.