| 摘要 |
<P>PROBLEM TO BE SOLVED: To start a motor through a reliable and simple control. <P>SOLUTION: A motor-driving circuit 100 drives a fan motor 4 on receipt of a controlling pulse signal CNT1 pulse-width modulated in accordance with a target number of rotation. A starting pulse-signal generation unit 16 generates the starting pulse signal SP1 of a predetermined duty ratio. A driving unit 10 drives the fan motor 4 through the pulse-width modulation, based on the driving pulse signal DRV1 transmitted from a control unit 14. The control unit 14 starts driving the fan motor 4 while it is kept stopped, at the moment that the duty ratio of the controlling pulse signal CNT1 is transferred from zero to nonzero. Further, the control unit 14 outputs the starting pulse signal SP1 as the driving pulse signal DRV1 for some starting period of time Ts since starting to drive, and outputs the controlling pulse signal CNT1 as the driving pulse signal DRV1 after a lapse of the starting period of time Ts. <P>COPYRIGHT: (C)2010,JPO&INPIT |
