Peak detector for detecting accurate pulse peaks produced by a magnetic head exhibiting residual magnetism

摘要

A peak detector for detecting accurate peaks of pulses recovered from a magnetic disk in the presence of residual magnetism by a magnetic head, but without the deleterious effects of such residual magnetism. The head supplies differential pulses as respective pulse trains to first and second peak detectors, respectively. The peaks detected in the first train of differential pulses are combined with the peaks detected in the second train, and an output signal produced as a function of the combined peaks is indicative of the pulse peaks. The respective peaks, which represent the positive and negative peaks of the pulses, are compared to a set of reference levels and, depending upon the relationship of those peaks with the reference levels, a gain error or an offset error is indicated. If the positive pulse peaks and negative pulse peaks exhibit substantially similar relationships with respect to the reference levels, a gain error is indicated. However, if the positive pulse peaks and negative pulse peaks exhibit dissimilar relationships with respect to the reference levels, an offset error is indicated.