| 摘要 |
PURPOSE:To detect simultaneously plural write abnormalities with a required minimum circuit by utilizing the fact that a counter electromotive force is generated by the inductance component of a coil when a write current to a magnetic head is turned on and off and detecting this counter electromotive force with an integrator and a comparator. CONSTITUTION:If write currents IW1 and IW2 are omitted as shown by broken lines, counter electromotive forces VH1 and VH2 are not induced in coils L1 and L2. Consequently, a comparator output Vout goes to the High level because an integrator output Vc falls to be lowered than a reference voltage Vref. That is, abnormality of write of the head is indicated. If write currents IW1 and IW2 are supplied but there is not transition or coil terminals are short- circuited or coil terminals are disconnected, counter electromotive forces VH1 and VH2 are not obtained, and the comparator output Vout goes to the high level to confirm abnormality. |
