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. 06, 1999
Filed:
Aug. 18, 1998
Scott E Blackburn, Temperance, MI (US);
Sergei F Kolomeitsev, Saline, MI (US);
Dana Corporation, Toledo, OH (US);
Abstract
A method and circuit for controlling a switched reluctance motor are provided. The method includes the steps of controlling a current in a phase coil of a motor phase of the motor during an active stage of the motor phase and controlling the current in the phase coil during an inactive stage of the motor phase. The latter step includes the substep of increasing the level of current in the phase coil for a predetermined period of time during the inactive stage of the motor phase. By increasing the current level during the inactive stage, the rate of current dissipation is reduced, thereby reducing acoustic noise. A circuit in accordance with the present invention includes a pair of one-shot circuits connected together in series and responsive to the end of the active stage of the motor phase. The second one-shot circuit generates an output signal that closes a switch connected to a phase coil of a motor phase of the motor for a predetermined period of time during the inactive stage of the motor phase. Closing the switch causes a level of current in the phase coil to increase during the inactive stage of the motor phase, thereby slowing the rate of current dissipation and reducing acoustic noise.