| 摘要 |
PURPOSE:To limit the continuously flowing current capacity of an inverter to the minimum limit by utilizing the square torque characteristic of a load and suitably varying the voltage/frequency of the output of the inverter. CONSTITUTION:If f<fmin when a contact 56a is operated by a comparator 53 which compares the set frequency f of an operating frequency setter 41 with the minimum starting frequency fmin at the additionally starting time, the comparator 53 operates, thereby operating contacts 53a, 53b. If f>fmax when the contact 56b is operated by a comparator 54 which compares the maximum starting frequency fmax with the set frequency f at the additionally starting time, the comparator 54 operates, thereby operating contacts 54a, 54b. The contacts 53a, 53b of the comparator 53 perform the switching operation from the operating frequency setter 41 to the minimum starting frequency setter 51, and the contacts 54a, 54b of the comparator 54 perform the switching operation from the setter 41 to the maximum starting frequency setter 52. |
