| 摘要 |
PURPOSE:To discriminate the use limit due to wear without manual operation, by detecting the quantity of wear on the basis of the peak level of the terminal voltage of a magnetic head at the write current driving time. CONSTITUTION:Write data (a) which is write information or information for detecting the quantity of wear of a magnetic head is supplied to a write current driving circuit 1. A terminal voltage (d) of a magnetic head 2 and a threshold voltage V1 are compared with each other, and an output (e) is supplied to the reset terminal of an SR type flip-flop 7. This flip-flop is set/reset repeatedly when the peak level of the terminal voltage (d) is higher than the voltage V1, and the flip-flop 7 is left set when this peak level is lower than the voltage V1. The operation of the flip-flop 7 is checked by a one-shot circuit 8 and an NOR circuit 9 to generate a wear detection output (h). |
