Apparatus, system, and method for controlling recording head substrate bias voltage
AssigneeInternational Business Machines Corporation
InventorsRobert Glenn Biskeborn, Stanley W. Czarnecki, Icko E. T. Iben, Larry LeeRoy Tretter
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Abstract
An apparatus, system, and method are disclosed for dynamically controlling a recording head substrate bias voltage. The apparatus includes a midpoint module and a substrate module. The midpoint module calculates a midpoint voltage of a plurality of data read elements and servo read elements contained in the head. The substrate module calculates a substrate bias voltage. The apparatus, system, and method dynamically control the substrate bias voltage post-assembly, minimizing certain head degradations and extending the life of associated head readers.
Claims19
An apparatus to dynamically control a substrate bias voltage, the apparatus comprising:
- a plurality of magnetic read elements associated with a head module;
- a midpoint module configured to calculate a midpoint voltage for each of the plurality of read elements associated with the head module as a function of a bias current and a head resistance;
- a substrate module coupled to the midpoint module, the substrate module configured to calculate a head substrate bias voltage for a substrate as a function of an average of the plurality of midpoint voltages;
- and
- a bias circuit that delivers the calculated head substrate bias voltage to the substrate.
A system to dynamically control a substrate bias voltage, the system comprising:
- a magnetic data storage device;
- a head substrate having a plurality of head elements;
- a storage controller that controls read-write operations of the plurality of head elements;
- and
- an apparatus coupled to the storage controller, the apparatus configured to determine a value of a substrate bias voltage for the substrate, the apparatus comprising:
- a midpoint module configured to calculate a midpoint voltage for each of the plurality of head elements as a function of a bias current and a head resistance;
- and
- a substrate module coupled to the midpoint module, the substrate module configured to calculate a head substrate bias voltage for a substrate as a function of an average of the plurality of midpoint voltages.
A signal bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform operations to dynamically control a substrate bias voltage, the operations comprising:
- calculating a head midpoint voltage for each of a plurality of head elements associated with a head module as a function of a bias current and a head resistance;
- and
- calculating a substrate bias voltage for a substrate as a function of an average of the plurality of head midpoint voltages.
An apparatus for storing magnetic data, the apparatus comprising:
- a head assembly coupled to a magnetic data storage device, the head assembly configured to perform read-write operations on a storage medium, the head assembly comprising a plurality of read elements;
- a midpoint module configured to calculate a midpoint voltage for each of the plurality of read elements associated with the head assembly as a function of a bias current and a head resistance;
- a substrate module configured to calculate a head substrate bias voltage for a substrate as a function of an average of the plurality of midpoint voltages;
- a bias circuit coupled to the head assembly, the bias circuit configured to deliver the head substrate bias voltage to a substrate;
- and
- a substrate power supply coupled to the bias circuit, the substrate power supply configured to power the bias circuit.
Dependencies are inferred from the claim text.