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:
Nov. 19, 2002
Filed:
Nov. 14, 2000
Ronnie E. Thebeau, Middletown, CT (US);
Daryl J. Marvin, Farmington, CT (US);
Christopher S. Czerwinski, Middletown, CT (US);
Neil A. Greiner, Wethersfield, CT (US);
Edward D. Piedra, Chicopee, MA (US);
Otis Elevator Company, Farmington, CT (US);
Abstract
The temperature ( ) of solid state switching devices in variable speed motor drives ( ), such as elevator motor drives, are utilized to reduce the load on the drive, by reducing the switching frequency ( ) or the commanded load ( ). The choice between the preferred non-switching zero state and an alternative zero state is determined ( ) by temperature ( ) of the switched transistor's anti-parallel diode. The rate of recognizing reduced temperatures is limited ( ) to avoid motor speed and/or load variations. The temperature may either be measured ( ) or determined ( ) from models utilizing manufacturer product specification and normalized thermal transient response from the transistor/diode package to a heat sink.