Apparatus and method for reducing spindle power and acoustic noise in a disk drive

摘要: An apparatus and method for reducing spindle power acoustic noise in a self-commutating brushless d.c. motor disk drive adjusts the commutation angle of until point optimum consumption is reached. In preferred approach implemented during operation, direction which to change determined such that decreased. The changed minimum identified. order determine correct change, varied first so long as decreasing. If varying results an increase consumption, second direction. During may be back forth maintain consumption. also minimizes torque ripple by determining profile storing memory table constant values indexed rotational position disk. As spins, its sensed current adjusted using corresponding value. this way, inversely produce substantially uniform output, or output additionally compensates structural resonance other properties. Still further, offset value applied proportional difference between average torque.