| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a drive device of a sensorless motor that performs stable start when the motor is started. <P>SOLUTION: The sensorless motor driving device is provided with a starting/oscillating circuit that generates first rectangular signals of a constant cycle; a doubler circuit that generates third rectangular signals that double 1/2 cycle immediately before each of the 1/2 cycle to a plurality of predetermined cycles at each 1/2 cycle of second rectangular signals whose cycle changes according to the rotational speed of the motor; a switching circuit that switches either one of the outputs of the starting/oscillating circuit and the doubler circuit to supply it to a drive circuit as a signal for conducting and controlling motor coils; and a determination circuit that determines whether or not the third rectangular signals generated during the period of the 1/2 cycle of the second rectangular signals has a plurality of cycles. The determining circuit switches the switching circuit from the starting/oscillating circuit side to the doubler circuit side after the 1/2 cycle, based on a determination result when it is initially determined that the third rectangular signals generated during the 1/2 cycle of the second rectangular signals has a plurality of cycles. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
