A novel low cost bipolar-starting and unipolar-running converter for extended torque-speed characteristics of spindle motor

Spindle motors are driving to high speed and compact size in Hard Disc Drive (HDD) area, particularly those in servers. In order to read and write the huge data with fast rate, the spin speed of spindle motor should be high with high starting torque. This paper presents a novel topology to a low cost converter which drives a spindle motor at high speed with high starting torque utilizing the bipolar starting and unipolar running algorithm. This topology is simple and developed with only eight switches in the converter to drive the spindle motor at high speed with high starting torque. The proposed scheme has been simulated on MATLAB/SIMULINK platform, the results are presented and discussed.