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:
Jul. 28, 1998
Filed:
Nov. 15, 1996
Ramani R Kalpathi, Ann Arbor, MI (US);
Dana Corporation, Toledo, OH (US);
Abstract
A method and circuit are disclosed for commutating a conduction cycle of a motor phase of a switched reluctance motor having a rotor portion thereof. The circuit includes a first switching device and a second switching device connected in series with a phase coil. A microcontroller closes both switching devices to connect the coil across a power supply to thereby initiate a conduction cycle. When a current level in the phase coil reaches a threshold level, only one switching device is modulated to control the current level between a local minimum level and a local maximum level. Rise and fall times of the current level between the local minimum and maximum levels are measured and an active phase time ratio is calculated using the rise and fall times. When the ratio, which is indicative of an angular position of the rotor in the switched reluctance motor, reaches a predetermined threshold value, the conduction cycle is commutated.