Contact detection and calibration for electrostatic fly height control in a disc drive

摘要

A disc drive includes a head with an air bearing surface that provides a fly height spacing. A fly height spacing control system provides a control signal to a head electrical connection on a head and a disco electrical connection on a disc. Fly height is controlled electrostatically. A disconnect circuit couples the control signal to the disc electrical connection. The disconnect circuit provides a disconnection of the control signal when contact is sensed. A contact sensor senses an electrical current component of the control signal that indicates contact between the head and the disc.