| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress a load given to a power supply device supplying power to a motor in detection of a position of a rotor when driving of the motor is started. <P>SOLUTION: A drive unit includes: an inverter section which has switching elements arranged for respective coils and switches on/off of the switching elements to energize a coil; an energization pattern determining section for selecting an energization pattern one by one from a plurality of energization patterns showing a direction of a current flowing to the coil in order and switching on/off of the switching element at a duty ratio corresponding to a maximum current value which the power supply device can supply on the basis of the selected energization pattern to energize the coil; a current application time measuring section for measuring energization time being time until a current value of the current flowing in the coil reaches a target current value at every energization pattern; and a rotor stop position estimating section for estimating a position where the rotor stops on the basis of energization time at every energization pattern which the current application time measuring section measures. <P>COPYRIGHT: (C)2013,JPO&INPIT |
