Patent ID: 7675255
Filing Date: 2010-03-09
Classification: G11B,H02P

Abstract:
1. A method for a BEMF voltage reduction in a storage device including an electric motor, the method comprising: selectively coupling by a motor controller, a winding power output of a plurality of winding power outputs of a power supply to an associated winding of an electric motor of a storage device during a servo operation period of said electric motor; disconnecting by the motor controller, all of the windings of the electric motor from all of the winding power outputs of the power supply during an entirety of a deceleration period of the electric motor to prevent any flow of a BEMF current into the winding power outputs of the power supply; providing by a servo controller in electrical communication with the motor controller, a BEMF control signal to the motor controller during the entirety of the deceleration period of the electric motor, wherein the BEMF control signal is representative of a comparison of a desired decelerated velocity profile of the electric motor and an actual decelerated velocity of the electric motor; connecting by the motor controller, at least one winding of the electric motor to a power return during at least a first segment of the deceleration period of the electric motor based on the BEMF control signal, to dissipate any BEMF voltage within the at least one winding of the electric motor; and disconnecting by the motor controller, the electric motor windings from the power return during a second segment of the deceleration period of the electric motor based on the BEMF control signal.