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:
Mar. 18, 1986
Filed:
Jul. 16, 1984
Tooru Tanahashi, Gifu, JP;
Isao Tadenuma, Inazawa, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An inverter, which supplies A.C. power to a motor for driving the cage of an elevator, is feedback-controlled by detecting the A.C. power by means of a detector. The detector provides an output (offset voltage) even when the operation of the inverter is at a stop. The output value fluctuates in accordance with the changes of circumstances such as temperature changes, and the inverter is affected by the fluctuations, so that the inverter generates power with which the motor produces a torque ripple. In order to solve this problem and to perform an operation of reduced torque ripple, the offset voltage of the detector is sensed, and a drive control signal for the inverter is properly changed on the basis of the sensed offset voltage.