| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor driver which can reduce the maximum loss. SOLUTION: A rectifier circuit 2 of the motor driver rectifies an AC current supplied from a three-phase AC power supply 10. A voltage step-down circuit 30 drops the input voltage Vin given from the rectifier circuit 2 with the switching operation of a switching element 3 to output an output voltage Vout. An inverter 8 converts a DC output voltage Vout of the voltage step-down circuit 30 to an AC voltage and applies the AC drive voltage Vm to a motor 20. When a preset value of the output voltage Vout of the voltage step-down circuit 30 is maximum, the switching element 3 maintains the ON state. As a result, the switching operation stops and the switching loss is minimized. |
