| 摘要 |
PURPOSE:To indicate the occurrence of abnormality to a user and to deal with the abnormality by indicating the occurrence of abnormality when the readout signal of a head output circuit drops in level abnormally and raising the level of the readout signal to its normal level. CONSTITUTION:The readout signal of the head output circuit 11 of a data reproducing device is processed by differential amplification 12, AGC 13, and smoothing 14, and the result is inputted to a voltage follower amplifier 15. The readout signal from this amplifier 15 is applied to a comparator 20 and compared with a preset reference level, thereby outputting an abnormality detection signal E when the readout signal is lower than the reference level. This signal E is latched by a CPU 22 through an FF 21 and a display device 23 and a gain control circuit 24 are operated according to the signal E. Then, the display device 23 indicates the occurrence of abnormality and a control circuit 24 controls the gain of the differential amplification 12 to raise the gain to a specific value from the normal value, thus dealing the occurrence of the abnormality.
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