Abstract: An air bearing slider is designed with two rails and a central pad that provide positive air bearing regions to the air bearing surface of the slider, and three recess regions that are etched to a constant depth. The rails are identical and are symmetrically disposed relative to a central longitudinal axis. Each rail includes three sections: a pitch adjustment pad, a leg, and a roll adjustment pad. The pitch adjustment pad provides a balanced pressure distribution at the leading edge and optimizes the overall pitch angle of the slider. The leg extends from the pitch adjustment pad and generates counter-pressure that partially opposes the load applied by the suspension. The roll adjustment pad extends from the leg and generates an air bearing force that compensates for roll generated during slider operation. This air bearing slider design achieves constant flying height and less vertical and pitch stiffness, which will result in low contact force for pseudo-contact applications.

Abstract: A low cost automatic frequency control system measures short duration radio frequencies with high a degree of accuracy within 0.5 MHz. The system is programmable to allow applicability over a wide range of frequencies within the required accuracy and various signal durations. The system includes circuits to digitize the source signal to a digital pulse train and asynchronously sample the pulse train to obtain a count of the positive edges of the pulses over a sufficient number of samples. A microprocessor computes the statistical average of the count and accurately determines the frequency of the source signal. The system further includes a feedback path to implement correction to the source signal based on the measured frequency.