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:
Jun. 16, 1987
Filed:
Oct. 10, 1986
Jerome Sears, Wyckoff, NJ (US);
Walter Parfomak, Wallington, NJ (US);
Walter Kluss, Clifton, NJ (US);
Allied Corporation, Morris Township, Morris County, NJ (US);
Abstract
A closed loop drive system for a permanent magnet motor (12) operable in a two-phase drive mode during a start cycle and a single phase drive mode thereafter during which the start cycle is reinitiated if the back EMF generated in a sensing winding (18) falls below a reference value. The permanent magnet motor (12) is driven as a two-phase motor with an increasing frequency input during the starting cycle and after initial starting is driven as a single phase motor as long as the back EMF induced in a stator sensing winding (18) remains above a predetermined value. A restart decision circuit (20) is provided which samples the back EMF induced into the stator winding (18) not being driven during single phase operation and initiates a restart cycle if the induced back EMF during single phase operation falls below a selected reference.