| 摘要 |
PURPOSE:To supply a pulsative AC current to a two-terminal magnetic head by connecting the current supply terminal of a driving circuit block to a constant current source through a current switch and closing this switch for a specific short time. CONSTITUTION:The current supply terminal VE1 of the driving circuit block consisting of a combination of switches S1-S4 which are opened and closed with gate signals G1-G4 is connected to the constant current source IS through a current switch S5. In this circuit constitution, the signals G1-G4 determine the direction of a recording current WW flowing to the magnetic head H. In this state, when the switch S5 is closed with the gate signal G5 for a time corresponding to the pulse width of the current, the current of the current source IS is sent to a driving circuit part and a pulsative current IW flows to the head H. For example, when the switch S5 is closed while the switches S1 and S4 are closed and the switches S2 and S3 are opened, a recording current flows in the plus direction throughout the closure period of the switch S5; when the switch S5 is closed while the switches S2 and S3 are closed and the switches S1 and S4 are open, the current IW flows in the minus direction throughout the closure period of the S5. |
