Various illustrative aspects are directed to a data storage device comprising a first spindle motor configured to rotate one or more disks in a first stack of disks, a second spindle motor configured to rotate one or more disks in a second stack of disks, and one or more processing devices configured to detect back electromotive force (BEMF) voltages generated by the first spindle motor and the second spindle motor. In other aspects the one or more processing devices can control speeds of the first spindle motor and the second spindle motor based on the detected BEMF voltages.

The present disclosure provides a driving circuit of a fan motor to shorten a start time. The driving circuit drives the fan motor with a sensor. A control logic circuit controls an inverter circuit connected to the fan motor according to a Hall signal that indicates a position of a rotor of the fan motor. When the driving circuit is given an instruction to start a rotation, if the fan motor rotates at a speed lower than a predetermined rotational speed, the drive circuit starts the fan motor by sequentially switching between a second state in which the rotor is fixed at an initial position, a third state in which the fan motor is forcibly and synchronously started, and a fourth state in which the fan motor is Hall-driven.

An apparatus includes a housing, a data storage magazine configured to hold a plurality of data storage devices, and a movable carriage disposed within the housing that is configured to selectively couple the data storage devices to a host device. The data storage magazine includes a set of magazine signal paths configured to provide signals to the plurality of data storage devices. The movable carriage includes a set of carriage signal paths configured to provide signals to the plurality of data storage devices. The apparatus includes a controller configured to power the plurality of data storage devices by selectively routing the signals via the set of magazine signal paths or the set of carriage signal paths.

An apparatus includes a housing, a data storage magazine configured to hold a plurality of data storage devices, and a movable carriage disposed within the housing that is configured to selectively couple the data storage devices to a host device. The data storage magazine includes a set of magazine signal paths configured to provide signals to the plurality of data storage devices. The movable carriage includes a set of carriage signal paths configured to provide signals to the plurality of data storage devices. The apparatus includes a controller configured to power the plurality of data storage devices by selectively routing the signals via the set of magazine signal paths or the set of carriage signal paths.

An apparatus includes a housing, a data storage magazine configured to hold a plurality of data storage devices, and a movable carriage disposed within the housing that is configured to selectively couple the data storage devices to a host device. The data storage magazine includes a set of magazine signal paths configured to provide signals to the plurality of data storage devices. The movable carriage includes a set of carriage signal paths configured to provide signals to the plurality of data storage devices. The apparatus includes a controller configured to power the plurality of data storage devices by selectively routing the signals via the set of magazine signal paths or the set of carriage signal paths.

An apparatus includes a housing, a data storage magazine configured to hold a plurality of data storage devices, and a movable carriage disposed within the housing that is configured to selectively couple the data storage devices to a host device. The data storage magazine includes a set of magazine signal paths configured to provide signals to the plurality of data storage devices. The movable carriage includes a set of carriage signal paths configured to provide signals to the plurality of data storage devices. The apparatus includes a controller configured to power the plurality of data storage devices by selectively routing the signals via the set of magazine signal paths or the set of carriage signal paths.

A data storage device is disclosed comprising a head actuated over a disk, and a spindle motor configured to rotate the disk. A pulse width modulated (PWM) control signal is generated having a frequency based on a PWM clock, the spindle motor is controlled using the PWM control signal, and a frequency of the PWM clock is swung between a minimum frequency and a maximum frequency at a swing rate.

A data storage device is disclosed comprising a head actuated over a disk, and a spindle motor configured to rotate the disk. A pulse width modulated (PWM) control signal is generated having a frequency based on a PWM clock, the spindle motor is controlled using the PWM control signal, and a frequency of the PWM clock is swung between a minimum frequency and a maximum frequency at a swing rate.

A server box embodiment is disclosed that generally comprises an array of dummy HDDs that share a common set of universal disk drive components in a master components module, or power module. Each dummy HDDs is constructed without expensive onboard chipsets that control the normal functionality of a standard HDD. By sharing expensive chipsets in a master components module (power module) money can be saved in building and selling the dummy HDD server. Embodiments envision a power module possessing the needed chipset functionality that is missing in a dummy HDD. The power module can be made to move from dummy HDD to dummy HDD supplying the necessary chipset in a shared manner when data is being stored or retrieved for client or end-user.

A server box embodiment is disclosed that generally comprises an array of dummy HDDs that share a common set of universal disk drive components in a master components module, or power module. Each dummy HDDs is constructed without expensive onboard chipsets that control the normal functionality of a standard HDD. By sharing expensive chipsets in a master components module (power module) money can be saved in building and selling the dummy HDD server. Embodiments envision a power module possessing the needed chipset functionality that is missing in a dummy HDD. The power module can be made to move from dummy HDD to dummy HDD supplying the necessary chipset in a shared manner when data is being stored or retrieved for client or end-user.