| 摘要 |
PURPOSE:To obtain position information with high quality by feeding back a speed signal formed by a speed signal forming circuit to a peak hold circuit so as to change the lowering width of the peak value in response to the speed signal. CONSTITUTION:The speed signal formed by a speed signal forming circuit 15 is fed back to the peak hole circuit 11 as a current value setting input signal P and fed to the base of a transmistor (TR) 2 whose collector is connected to the emitter of a TR 1 and whose emitter is connected to a voltage Vee. Then the peak hole circuit 11 discharges a voltage stored in a capacitor (c) in response to the speed of the head by the operation of the TR 2 and a current value setting input signal (p). Thus, the down value of the peak is changed depending on the speed of the head so as to obtain position information with high quality.
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