| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a drive circuit for a brushless DC motor which eliminates rapid change in a waveform of current flowing through a motor coil, thereby reducing noise caused by vibration. <P>SOLUTION: A comparator produces a PWM signal by comparing potential level of a first triangular signal, produced from a phase advance signal by advancing an FG signal outputted by a speed detector, with potential level of a second triangular signal produced from a reference clock. The PWM signal replaces the rise and fall of a motor drive signal, thereby reducing the change rate of current for driving a motor coil. <P>COPYRIGHT: (C)2012,JPO&INPIT |
