| 摘要 |
PURPOSE:To prevent an unreliable magnetic head feeding speed calculated from the output signal of an AD converter at its discontinuous section from being used for controlling the magnetic head feeding operation, by providing a means which inhibits the output of a calculating circuit within a prescribed time period after a track passing signal is obtained. CONSTITUTION:A calculating circuit 6 calculates the difference between the speed of a magnetic head at the present position and an aimed speed from a track passing number obtained by a counter 3 at every, for example, 200mus and an inter-track position signal obtained by an AD converter 5 and outputs the difference, but the output is inhibited for a fixed time period by a selection circuit 7 after a track-pulse generating circuit 2 generates a track passing signal. During the period when the output is inhibited, the stored content of a register 8 is selected by the selection circuit 7 and sent to a control section 9 instead of the output. Therefore, erroneous control at the control section 9 can be prevented. |
