Patent ID: 7079350
Filing Date: 2006-07-18
Classification: G11B

Abstract:
1. A control circuit for controlling a motor assembly having a coil with first and second nodes and having a movable arm, the control circuit comprising: a drive circuit operable to be coupled to the first and second nodes of the coil, to receive a control signal, a current signal indicating a magnitude of a current flowing through the coil, and a speed signal, to generate a drive signal in response to the control, current, and speed signals to drive the coil with the drive signal during drive periods, and to uncouple the drive signal from the coil during measurement periods that alternate with and are separate from the drive periods, and wherein the drive circuit generates the drive signal responsive to the speed signal only during hard-parking and hard-unparking of the movable arm; and a sensor circuit coupled to the drive circuit and having first and second sensor nodes operable to be respectively coupled to the first and second nodes of the coil such that no element is in series with the coil between the first and second sensor nodes, the sensor circuit operable to generate the speed signal having a level that corresponds to the speed of the arm.