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. 28, 2000
Filed:
May. 06, 1999
John Kardash, Ione, CA (US);
Kwong T Chan, Pleasanton, CA (US);
Quantum Corporation, Milpitas, CA (US);
Abstract
A method and apparatus for driving a decelerating a multi-phase wound electric motor having a rotor and multiple phase coils arranged as a stator, wherein each phase coil has a first terminal and a second terminal, and the first terminals of the phase coils are connected together at a center tap. Commutation signals in response to BEMF voltages in the phase coils select a first and a second coil in each commutation state, such that when energized the first and second coils are capable of providing forward torque to the rotor based on the rotational position of the rotor relative to the phase coils. In each commutation state, the second terminal of the first is electrically connected to an upper voltage supply. For applying forward torque to the rotor, the second coil is electrically connecting the second terminal of the second coil to a lower voltage supply, wherein the upper voltage supply is at a higher voltage than the lower voltage supply. Otherwise, to apply reverse torque to the rotor to decelerate the rotor, the second terminal of the second coil is electrically connected to the upper voltage supply during at least a portion of each commutation state, causing a reverse current to flow in the first and second coils to provide reverse torque to the rotor. During each commutation state when the second terminal of the first coil is electrically connected to the upper voltage supply and the second terminal of the second coil is electrically connected to the lower voltage supply, forward current flows in a direction from the first coil to the second coil, inducing forward torque on the rotor. Further, when the second terminals of the first and the second coils are electrically connected to the upper voltage supply during at least a portion of each commutation state, reverse current flows in a direction from the second coil to the first coil, inducing reverse torque on the rotor.