| 摘要 |
PURPOSE:To measure accurately the using time of a magnetic head and to display it, by providing a memory which stores the contents of a counter that integrates the pulses of a pulse generator driven when a recorder is set in a reproduction mode and a display which performs display by the output signal given from the memory. CONSTITUTION:An arithmetic circuit 2 delivers a prescribed level of DC control voltage as long as a recorder is set in a reproduction mode and not in a pause mode. The output of the DC control voltage is supplied to a pulse generator 3, and meanwhile a pulse of a fixed width is delivered and supplied to a counter 4. The pulses supplied to the counter 4 are counted and stored with integration to a memory 5 in the form of a digital quantity. At the same time, a prescribed quantity of the wear-resistant lifetime of a head, etc. is written to a memory 6. A comparator 8 compares the contents between memories 5 and 6, and the contents of the memory 5 are delivered when coincidence is obtained from the comparison. Furthermore, the contents of the memory 5 are delivered when necessary by turning on a manual switch 9 and then supplied to a display driving circuit 10. |
