Abstract: An adapter which allows two or more hard disk drives to conduct self-testing in a single test rack slot is provided. Testing can be individually controlled for the various HDDs in a slot. Peltier cell devices or other cooling or heating devices can be controlled to achieve individualized temperature control for HDDs in the test rack slot.

Abstract: A magneto-optical clock head is disclosed. The magneto-optical clock head allows a longitudinally recorded clock track to be read from a disk surface from a position outside of a head-disk assembly (HDA). The clock track has sections of alternating magnetization which define transitions. Importantly, the magneto-optical clock head is used to sense the transitions using the transverse Kerr effect, as opposed to the longitudinal Kerr effect as used in one prior technique. In one embodiment, the magneto-optical clock head includes a light source for generating a p-polarized beam which is aligned in such a manner that it strikes the clock track. A reflected beam is then produced which has an intensity that varies based upon the direction of the magnetization of the sections of alternating magnetization of the clock track due to the transverse Kerr effect.

Abstract: Provided is a disk drive with a disk and an actuator assembly on which a communication device is mounted for communication with the disk. Position information read from the disk is processed through a channel that generates an analog position error signal that is then converted to a digital position error signal by a first signal converter. Based on the digital position error signal, a controller determines whether realignment of the communication device with the disk is required. The operation of the first signal converter is only periodically required. When realignment is required, then a digital position control signal is generated by the controller and is then converted to an analog position control signal by a second signal converter, which shares circuitry with the first signal converter. Normally, the second signal converter is operating to realign the communication device. Therefore, the shared circuitry is normally operating as part of the second signal converter.

Abstract: An apparatus and method for torque disturbance precompensation in a disk drive spindle motor includes an amplifier for providing current to the spindle motor in response to an input signal. A velocity detector determines the velocity of the motor, which is then compared to a predetermined velocity to generate an error signal. Compensator elements of the control loop develop an actuating signal from the error signal. The actuating signal is then summed with a torque correction value provided by a look-up table. The torque correction value precompensates the motor by causing the amplifier to provide an additional incremented current to the motor. The additional current corrects the torque disturbance resulting from the movement of the heads across the disk.

Abstract: Disclosed is a system and method for mounting disk drive motors. The motor spindle and the drive shaft are rotatably supported by the disk drive chassis. The drive shaft of the motor extends through the printed circuit board of the disk drive and into a central aperture in the motor stator. Between the motor stator and the printed circuit board is a stator-spacer which positions and aligns the stator. The stator is mechanically mounted and electronically connected to the printed circuit board by means of stator retaining pins. The rotor bell of the motor is coaxially mounted to the drive shaft and inductively disposed about the stator.