| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent a ready signal representing a stable rotational speed in a state in which the rotational speed of a motor is low immediately after starting, from being outputted by mistake. <P>SOLUTION: A first determination circuit 3 compares a first frequency signal f1 from a frequency generator provided in a brushless motor with a predetermined first reference signal f0, and outputs a first determination signal as a ready signal when the circuit determines that the first signal f1 is near the first signal f0. A second determination circuit 7 compares a second frequency signal f2 from a switching element for switching and energizing a drive winding of a stator side in the motor with a predetermined second reference signal f0', and outputs a second determination signal when the second signal f2 is lower than the second signal f0'. An inhibiting circuit 5 inhibits the output of the first signal when the second determination signal is outputted. <P>COPYRIGHT: (C)2004,JPO |
