Abstract:
A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.
Abstract:
A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.
Abstract:
A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.
Abstract:
A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.
Abstract:
A method comprises writing a waveform on a magnetic recording medium using a heat-assisted magnetic recording apparatus which includes a laser. The method also comprises reading back the waveform from the medium, and detecting one or more transition shifts in the readback waveform indicative of a mode hop of the laser. The method further comprises measuring a metric of the one or more transition shifts.
Abstract:
A data storage system includes a recording head and a compensating resistor. The recording head has a heating element. The compensating resistor is in electrical series with the heating element and is external to the recording head. A method includes applying an alternating current at a first angular frequency to a recording head. A voltage drop across the recording head heating element is measured. A component of the voltage drop is extracted. The component has a frequency that is three times the frequency of the first angular frequency.
Abstract:
A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.
Abstract:
A head transducer, configured to interact with a magnetic recording medium, includes a first sensor having a temperature coefficient of resistance (TCR) and configured to produce a first sensor signal, and a second sensor having a TCR and configured to produce a second sensor signal. One of the first and second sensors is situated at or near a close point of the head transducer in relation to the magnetic recording medium, and the other of the first and second sensors spaced away from the close point. Circuitry is configured to combine the first and second sensor signals and produce a combined sensor signal indicative of one or both of a change in head-medium spacing and head-medium contact. Each of the sensors may have a TCR with the same sign (positive or negative) or each sensor may have a TCR with a different sign.
Abstract:
A flexible member is coupled between an actuator arm and a slider. The flexible member facilitates relative motion in a tangential direction of a rotating medium. The relative motion is detected via a displacement sensor, and a friction between the slider and the rotating medium is determined based on the sensed relative motion.
Abstract:
Changes in the thermal boundary condition near a close point of an ABS to a media indicate proximity of the ABS with the media. Before contact, heat conduction from the ABS is primarily through convective and/or ballistic heat transfer to air between the ABS and the media. After contact, heat flux primarily flows from the ABS to the media through solid-solid conductive contact. Further, a light source within a HAMR transducer head may create additional thermal variations within the transducer head. These thermal variations create temperature variations within the transducer head. Two resistance temperature sensors on the transducer head at varying distances from the close point and/or light source measure these temperature variations. A temperature difference between the two resistance temperature sensors indicates proximity of the close point to the media and/or light output.