| 摘要 |
PURPOSE:To suppress a vibration at a low speed rotation time by varying the current value of an exciting current in response to the rotating speed of a pulse motor. CONSTITUTION:A motor drive circuit has current setting resistors 20a-20c, and a switch 21 is controlled by a changeover controller 22. The controller 22 receives a high and low mode set signal from a terminal of a mode flip-flop 23 and a pulse signal train of the pulse width of the prescribed time (t) from a oneshot multivibrator 24. A resistor 20c is connected at a high speed time, it is set to a current set value I3 to control the current of the pulse motor. A resistor 20a is connected only for the prescribed time (t) from the multivibrator 24 at a low speed time, 20b is then connected, a large current I1 is flowed at phase switching time, and a low current I2 is then flowed to control. The amplitude of the current set value becomes a relation of I2<I2<I3. |
