According to one embodiment, a magnetic recording and reproducing device includes a magnetic recording medium, a magnetic head, and a processor. The magnetic head includes a first reproducing element portion and a second reproducing element portion. The processor is configured to acquire a first signal and a second signal, and to output an output signal according to either one of the first signal and the second signal. The first signal is obtained by reproducing information recorded on a first recording region by the first reproducing element portion. The second signal is obtained by reproducing the information recorded on the first recording region by the second reproducing element portion.

A storage device includes a transducer head with multiple write elements having write poles of different sizes. For example, the transducer head may include two write poles of different width configured to write to a same surface of a storage medium. A controller of the storage device is configured to selectively engage one of the multiple write elements to write data to the storage medium.

A magnetic disk device includes a control circuit, and a disk unit including a plurality of magnetic disks, a plurality of magnetic heads configured to read or write data from or to the magnetic disks, a first actuator configured to move the magnetic heads, a plurality of second actuators each configured to move the corresponding magnetic head, and a switch circuit configured to connect the control circuit and one of the second actuators. The control circuit is configured to transmit to the disk unit an instruction in which one of the magnetic heads is specified, control one of the second actuators corresponding to the specified magnetic head to move the magnetic head via the switch circuit, and based on a signal from the one of the second actuators, determine whether an error occurs in the one of the second actuators.

A magnetic disk device includes a control circuit, and a disk unit including a plurality of magnetic disks, a plurality of magnetic heads configured to read or write data from or to the magnetic disks, a first actuator configured to move the magnetic heads, a plurality of second actuators each configured to move the corresponding magnetic head, and a switch circuit configured to connect the control circuit and one of the second actuators. The control circuit is configured to transmit to the disk unit an instruction in which one of the magnetic heads is specified, control one of the second actuators corresponding to the specified magnetic head to move the magnetic head via the switch circuit, and based on a signal from the one of the second actuators, determine whether an error occurs in the one of the second actuators.

The present disclosure provides a switch device. The switch device includes: a switch element, including a gate, a drain, a source, a back gate, a first body diode disposed between the drain and the back gate and a second body diode disposed between the source and the back gate; a first switch circuit, including a first switch connected between the back gate and an application end at ground potential; and a second switch circuit, including a second switch connected between the back gate and the source.

Embodiments of the present invention provide methods, systems, and computer program products for compensating for loss of current through shorted tunneling magnetoresistance (TMR) sensors. In one embodiment, for a magnetic head having multiple TMR read sensors, a first voltage limit is set for most parts and a second voltage limit is set for all of the parts. A number of TMR read sensors which are allowed to function between the first and the second voltage limits is determined using a probability algorithm, which determines the probability that the application of the second voltage limit will result in a dielectric breakdown within an expected lifetime of a drive is below a threshold value. For the number of TMR read sensors which are allowed to function at voltages between the first and second voltage limits, a determined subset of those sensors are then allowed to function at the second voltage limit.

According to one embodiment, a magnetic recording and reproducing device includes a magnetic recording medium, a magnetic head, and a processor. The magnetic head includes a first reproducing element portion and a second reproducing element portion. The processor is configured to acquire a first signal and a second signal, and to output an output signal according to either one of the first signal and the second signal. The first signal is obtained by reproducing information recorded on a first recording region by the first reproducing element portion. The second signal is obtained by reproducing the information recorded on the first recording region by the second reproducing element portion.

Embodiments of the present invention provide methods, systems, and computer program products for compensating for loss of current through shorted tunneling magnetoresistance (TMR) sensors. In one embodiment, for a magnetic head having multiple TMR read sensors, a first voltage limit is set for most parts and a second voltage limit is set for all of the parts. A number of TMR read sensors which are allowed to function between the first and the second voltage limits is determined using a probability algorithm, which determines the probability that the application of the second voltage limit will result in a dielectric breakdown within an expected lifetime of a drive is below a threshold value. For the number of TMR read sensors which are allowed to function at voltages between the first and second voltage limits, a determined subset of those sensors are then allowed to function at the second voltage limit.

Embodiments of the present invention provide methods, systems, and computer program products for compensating for loss of current through shorted tunneling magnetoresistance (TMR) sensors. In one embodiment, for a magnetic head having multiple TMR read sensors, a first voltage limit is set for most parts and a second voltage limit is set for all of the parts. A number of TMR read sensors which are allowed to function between the first and the second voltage limits is determined using a probability algorithm, which determines the probability that the application of the second voltage limit will result in a dielectric breakdown within an expected lifetime of a drive is below a threshold value. For the number of TMR read sensors which are allowed to function at voltages between the first and second voltage limits, a determined subset of those sensors are then allowed to function at the second voltage limit.