| 摘要 |
PURPOSE:To reduce a noise by smoothing a switching voltage waveform by inserting a series resistor and a parallel capacitor between a switching element and an exciting coil. CONSTITUTION:A starting voltage V1 is applied by switching a transistor T6. In this case, a starting voltage waveform is smoothed by a time constant circuit of a resistor R1 and a capacitor C1, a shock at a motor drive time is alleviated to reduce a noise. A pulse width (t) of a drive pulse signal (C) for turning ON the transistor T6 is set to obtain the prescribed drive torque with a pulse width in response to a rotating speed by a pulse width controller 6. Thus, starting torques adapted for the speeds can be obtained. |
