New Motor Control Methods for Home VCR

The development of a new method of driving the brushless DC motor, called the QUASI-SINE WAVE method, reduces motor torque ripple to one quarter that of the conventional method. New methods for controlling the noiseless still and slow modes have also been developed; the former being to drive the capstan motor corresponding to the time interval between the noise band position and the head switching signal, while the latter controls the capstan motor in the drive-coast-damp mode, and takes care of stop control. The circuits required for these methods have been incorporated in three IC´s.