Patent ID: 6282046
Filing Date: 2001-08-28
Classification: G11B

Abstract:
A machine readable storage device having stored therein encoding instructions for executing a process for limiting energy consumption in a disk drive system including a disk having a plurality of tracks formed thereon, a spindle motor for rotating the disk in response to a spindle current, the spindle motor rotating said disk at a nominal speed while the spindle current has a nominal value, an arm assembly for positioning the head relative to the tracks of the disk, an actuator for driving the arm assembly in response to an actuator current, said process being performed during periods of a deceleration sequence for positioning the head at a target track, said process comprising the steps of:determining a reduced spindle current value which is less than said nominal value during a spindle energy deferring period;during each of a plurality of sampling intervals transpiring during said spindle energy deferring period,determining a deferred spindle current value which is proportional to the difference between said nominal spindle current value and said reduced spindle current value, andadding said deferred spindle current value to an accumulation of prior deferred spindle current values to develop a measure of deferred spindle energy; anddetermining an increased spindle current value which is greater than said nominal spindle current value during a spindle energy compensating period, said increased spindle current value for adding a quantity of compensating spindle energy which is approximately equal to said measure of deferred spindle energy, wherein said spindle energy deferring period and said spindle energy compensating period both during the deceleration sequence.