| 摘要 |
PURPOSE:To provide a motor speed controller that enables a constant speed control circuit to stably operate without being affected by a position detection signal noise. CONSTITUTION:Position detection signals [1], [2] and [3], output from a magnet position detector 1 for rotor use, are inputted to a motor drive circuit 2 after they have been delayed for a predetermined time by a delay circuit 8. The position detection signal [1] is inputted to a constant speed control circuit 4, and the phase of this signal is compared with the phase of a reference clock 5. Noise is induced when power transistors T1-T6 of the motor drive circuit 2 are turned on, and noise also appears on the position detection signal [1]. However, a rise of this signal [1] occurs at a time which is different from the switching of the power transistors T1-T6 because of the previously mentioned delay, and hence the constant speed control circuit can operate stably. |
