| 摘要 |
PURPOSE:To core with a signal which is recorded at a high speed and with high density by impressing a high voltage to a coil in an initial period, and subsequently, impressing a low voltage and controlling a recording current flowing to the coil, in each one cycle period of a current flowing to the coil of a magnetic head. CONSTITUTION:In an initial period of a current pulse, a high voltage +V1 is impressed to a coil 1, and after a current has reached a stationary value, a low voltage +V2 is impressed to the coil 1 by switching a terminal of a changeover switch 5. Even when an operation in terminals (a), (b) of a changeover switch 4 is an ideal square wave pulse, as for a current waveform in points (c), (d), its become a rounding shape by C, R and L components which the coil 1 has, and when a switching frequency of the changeover switch 4 becomes high, the case a rise period becomes longer than one pulse width is generated. Therefore, in order to shorten the rise period, a recording current is increased suddenly by impressing the high voltage +V1 to the coil in the rise period, and in other period, a constant recording current is allowed to flow to the coil 1 by impressing the low voltage +V2. |
