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. 12, 1985
Filed:
Jun. 27, 1983
Masami Nomura, Nagoya, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
The disclosed AC elevator control system comprises a converter for converting a three-phase AC power applied to it through an electromagnetic switch closed for the start of an associated elevator car, to a direct current, and an inverter for inverting the direct current smoothed by a smoothing capacitor to a three-phase AC power with a variable voltage at a variable frequency which is supplied to a three-phase induction motor for controllably traveling the elevator car. A rectifier is connected across the smoothing capacitor through an impedance element to continuously apply a rectified voltage from the firstmentioned AC power to the capacitor and a voltage sensor relay connected across the capacitor senses the voltage on the latter and prevents the electromagnetic switch from being closed when the sensed voltage is low.