| 摘要 |
PURPOSE:To accurately control the position of a magnetic head by providing means for controlling an exciting current to a different exciting phase of the motor at a plurality of steps. CONSTITUTION:Drive circuits 4A, 4B of exciting phases 1A, 1B of a step motor 1 are not only switched in a current direction by the input signals of input terminals E, F, but and the current value is controlled by the input signals of input terminals G, H. A moving direction designation signal A is input to an excitation signal generator 3, and also input to one input terminal of an XOR gate 5B. The gate 5B controls the input terminal G of the drive circuit 4A through an inverter 6 and directly controls the input terminal H of the drive circuit 4B. Exclusive OR of excitation signals C, D output from the generator 3 is taken by an XOR gate 5A, and the output signal of the gate is input to the other input terminal of the gate 5B. |
