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:
Aug. 12, 1980
Filed:
Sep. 19, 1978
Robert F Bourke, Kamiah, ID (US);
David M Thimmesch, Elgin, IL (US);
Gould Inc., Rolling Meadows, IL (US);
Abstract
A propulsion system for an electric vehicle in which a chopper is used to provide controlled DC power to a separately excited DC propulsion motor. In order to provide increased torque for comparatively short intervals to meet on-the-road requirements, the propulsion motor is provided with two sets of shunt field windings, and switch means are provided for connecting the windings in series or in parallel dependent upon the torque demands on the system. Normally the system is operated with the shunt field windings in series. To meet transient demands for increased torque, such as rapid acceleration from a stop light or improved gradability on hills, means are provided for detecting such increased torque demands and switching the field windings from series to parallel configuration thereby increasing the field flux and causing the motor to produce increased torque. The parallel connected field windings compensate for the demagnetizing effect of high armature currents without the need for a series field winding.