| 摘要 |
PURPOSE:To decrease number of required components and production cost and to improve the reliability by selecting any of a filtered signal and a signal not filtered by a band stop filter and comparing the selected signal with a reference value. CONSTITUTION:A transistor (TR) 11 as a means selecting any of the filtered signal and the signal not filtered by the band stop filter 8, comparison circuits 1', 2' comparing the signal value selected by the TR11 with reference values A and B, inverting circuits 5, 6 and a latch circuit 7' constitute the titled circuit. In using a track pass signal, a selection signal M is turned off to interrupt the TR11 and the track pass signal is formed in this state. Further, in applying positioning control to the magnetic head on a prescribed track, the selection signal M is turned on to conduct the TR11. In this state, the magnetic head position signal S is filtered by the band stop filter 8 and then the off-track is supervised. |
