Detection system using heating element temperature oscillations

摘要

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.

主权项

1. An apparatus, comprising:
a magnetic recording head that includes a heating element; a compensating resistor in electrical series with the heating element and external to the recording head and, wherein the heating element has a resistance that varies with temperature and the resistance of the heating element and a resistance of the compensating resistor are approximately equal; an alternating current source configured to supply an alternating current at a first angular frequency to the heating element; wherein a spacing between the head and a magnetic recording medium is indicated by a difference between a voltage drop across the compensating resistor and a voltage drop across the heating element.