| 摘要 |
PURPOSE:To decrease a power loss by controlling a motor in its speed from switching controlled voltage. CONSTITUTION:A power transistor serving as a power switching part 14 is switched on and off to corresponding to a pulse duty of a pulse width modulation signal 13 to control mean voltage applied to a motor 9 and its direction by a selector circuit in a direction control part 8 connected in series to the motor 9; thus, it is rotated in a desired direction in a desired speed. A semiconductor element, serving as the power switching part, generates a flow of large collector current when the pulse width modulated signal is in pulse on, and a flow of small collector current when the pulse width modulated signal is in pulse off. |
