| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to control an AC motor adequately just after its starting even when the AC motor is driven at a low voltage for the starting. SOLUTION: A driving controller includes an AC motor 2 for generating a rotation detecting signal with changeable frequency in accordance with the revolutions, and a control means 3 for generating a pulse width modulation signal with changeable pulse width in accordance with the revolutions. The control means 3 reduces the frequency of the AC signal applied to the AC motor 2 at the start of driving while a driving start signal for the AC motor 2 is generated, and controls the driving start signal on the basis of the frequency of the rotation detecting signal from the AC motor 2. In addition, the driving controller includes a voltage comparator 8 for changing the pulse width modulation signal into a given voltage, and a driver 6 for driving an oscillator by the output voltage from the voltage comparator 8, and changing the voltage into an AC signal to drive the AC motor 2. |
