| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a rotation control device capable of controlling the number of rotations of a motor by changing a duty ratio of a pulse width modulation clock. <P>SOLUTION: The rotation control device 100 controls the number of rotations of a motor by changing a current value of a difference signal to be output based on a pulse width modulation clock signal having a duty ratio as a ratio between the width of a 1-pulse HI signal and a 1-pulse period and a motor rotation number clock signal. The rotation control device 100 includes a duty ratio change generating circuit 105 for generating a pulse width modulation clock signal having a predetermined duty ratio in response to the required number of rotations; a smoothing circuit 112 for smoothing the pulse width modulation clock signal to output the smoothed signal as a DC voltage; and a changeover circuit 113 for changing over a switch of a switch circuit connected to a wiring through which the difference signal flows on the basis of a voltage value of the DC voltage. <P>COPYRIGHT: (C)2010,JPO&INPIT |
