A disk drive comprises a controller (70) that calculates a drive signal for positioning a head at a desired track on the basis of a desired track-position signal and a measured head-position signal, and a drive circuit for driving a voice-coil motor. The drive circuit includes a current feedback amplifier (21) and a voltage feedback amplifier (50), which can be selectively used. The controller (70) is provided with a speed limiter for determining a maximum speed limiting the speed of a head. The voltage feedback amplifier of the drive circuit is used when the head-position signal is unstable or otherwise malfunctioning, and the current feedback amplifier of the drive circuit is used when the head-position signal is normal.

 
Web www.patentalert.com

< Efficient transition from class D to linear operation in dual-mode voice coil motor controllers

< Head position control method, disk device, and servo track write method

> Screw attachment from exterior of disk drive enclosure for motors with mount bracket screw bolt pattern diameter larger than the motor hub outside diameter

> Drive level flow-field conditioning to reduce flow field turbulence
~ 00234