| 摘要 |
<P>PROBLEM TO BE SOLVED: To restrain burning of a circuit, and provide reduction in size and manufacturing cost. <P>SOLUTION: Each control circuit of an actuator select either of a first exciting mode or a second exciting mode, and controls driving of a motor with the selected exciting mode. With the first exciting mode, a first current limit value I<SB>1</SB>which is larger than a rated current value is taken as a maximum current, and a current exceeding a second current limit value I<SB>2</SB>which is lower than the rated current value excites the motor in a pulse condition, therefore the current at or more than the rated current value can be fed into the motor to obtain a larger torque. The current exceeding the second current limit value I<SB>2</SB>excites the motor in the pulse condition, the mean current can be lowered than the rated current value, thus preventing the burning of the driving circuit. On the other hand, with the second exciting mode, the second current limit value I<SB>2</SB>lower than the rated current value is taken as the maximum current to continuously excite the motor, thus obtaining the torque smaller than the first exciting mode. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
