In one embodiment, a computer-implemented method includes determining whether a medium in a drive is in motion, the drive being mounted in a receptacle, in response to determining that the medium is in motion, preventing physical removal of the drive from the receptacle, and in response to determining that the medium is not in motion, allowing physical removal of the drive from the receptacle. In another embodiment, a computer program product for controlling removal of a drive includes a computer readable storage medium having program instructions embodied therewith. The computer readable storage medium is not a transitory signal per se. The program instructions are readable and/or executable by a computer to cause the computer to perform the foregoing method.

A method for adjusting a voltage of a supercapacitor is disclosed, the method, which is used to retard aging of the supercapacitor and extend a service life of the supercapacitor, includes: acquiring information that carries a system service volume; configuring a size of an available capacity value of the Cache according to the information; and adjusting a working voltage of the supercapacitor according to the configured size of the available capacity value of the Cache.

A data storage device is disclosed comprising a head actuated over a disk, and a spindle motor configured to rotate the disk, wherein the spindle motor comprises a plurality of windings. The windings of the spindle motor are commutated based on a commutation sequence while applying a driving voltage to each winding, wherein the driving voltage comprises an operating polarity during normal operation. When a supply voltage falls below a threshold while the spindle motor is rotating the disk, the spindle motor is configured into a power generator by at least reversing the polarity of the driving voltage for an interval and then reversing the polarity of the driving voltage back to the operating polarity.

According to one embodiment, a monitoring unit of a magnetic disk device monitors a supply voltage supplied to a plurality of actuators by a first threshold value at which power supply by back electromotive force of a motor is started, and a second threshold value that is larger than the first threshold value. In a case where the supply voltage is lower than or equal to the second threshold value and is higher than the first threshold value, a controller interrupts execution of processing of reading/writing data to a magnetic disk in at least one of the actuators according to a predetermined condition based on execution status of the processing in the actuators.

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.

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.

According to one embodiment, there is provided a disk device including a head, a disk, a first motor, and a first circuit. The disk has a recording surface. The first motor causes the head to seek along the recording surface. The first circuit can switch between a first state and a second state. The first state is a state where a current path of the first motor is electrically cut off from a first electricity storage unit. The second state is a state where the current path of the first motor is electrically connected to the first electricity storage unit.

The present disclosure generally relates to an electronic circuit and method of operating thereof to back up write cache data on DDR memory in data storage devices during an emergency power off (EPO). The method involves using a power management integrated circuit (PMIC), a combo driver and one MOSFET for regulator output. The method involves detecting a voltage value that is below a predetermined threshold value, retracting a write head away from a hard disk drive (HDD), backing up data, and then resetting the HDD after the backup is complete. The backing up and retraction may occur in parallel or in sequence. The method utilizes the spindle back-electromotive force (BEMF) power to have sufficient power to make the backup. If the power from the spindle BEMF is too low, then the retraction is suspended and a high impedance is present to lighten the load until the BEMF recovers before the power on reset. As such, the back-up data is not reset and volatized by a lack of power.

The half-bridges driving a multiphase motor are controlled to perform a sequence of operations to support charging a hold capacitor. First, in a brake configuration, the half-bridge transistors are controlled such that either high-side transistors or low-side transistors of the half-bridges are turned on. Second, in an active step-up configuration, the half-bridge transistors are controlled such that the high-side transistor of a first half-bridge and the low-side transistor of a second half-bridge are both turned on and the low-side transistor of the first half-bridge and the high-side transistor of the second half-bridge are both turned off. Third, in an active brake configuration, the half-bridge transistors are controlled such that the low-side transistor of the first half-bridge and the high-side transistor of the second half-bridge are both turned on and the high-side transistor of the first half-bridge and the low-side transistor of the second half-bridge stage are both turned off.

According to one embodiment, a monitoring unit of a magnetic disk device monitors a supply voltage supplied to a plurality of actuators by a first threshold value at which power supply by back electromotive force of a motor is started, and a second threshold value that is larger than the first threshold value. In a case where the supply voltage is lower than or equal to the second threshold value and is higher than the first threshold value, a controller interrupts execution of processing of reading/writing data to a magnetic disk in at least one of the actuators according to a predetermined condition based on execution status of the processing in the actuators.