| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor control circuit that produces less switching loss, is efficient and economical and is easy to control with reliability. SOLUTION: When a switching element 41 is off, a rectifier circuit comprising a first diode bridge 21 and filter capacitors 23, 25 is configured as a full-wave rectifier circuit. When the switching element 41 is on, the rectifier circuit is configured as a voltage doubler rectifier circuit. Further, the switching element 41 is PWM (Pulse Width Modulation)-controlled by means of a controller 11. Thereby, the output directcurrent voltage of the rectifier circuit is varied under control within the range of, for example, approx. 140 volts through 280 volts and switching is performed between 140 volts and 280 volts to reduce switching loss. |
