| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform phase control in which any failure is hardly generated by, even when the voltage waveform of an AC power source fluctuates, performing phase control corresponding to the fluctuation. <P>SOLUTION: The power control method for performing phase control by using an AC power to be supplied from an AC power source 400 includes: generating a zero cross signal Sz showing a first level according as the absolute value of an AC voltage V is equal to or less than a predetermined value, and showing a second level according as the absolute value of the AC voltage is more than the predetermined value; detecting zero cross width as time width when the absolute value of the AC voltage V is equal to or less than a predetermined value and non-zero cross width as time width when the absolute value of the AC voltage is equal to or more than the predetermine value in the zero cross signal Sz; detecting the frequency and voltage value of the AC voltage V on the basis of the detected zero cross width and the detected non-zero cross width; and performing phase control in accordance with the detected frequency and voltage value of the AC voltage V. <P>COPYRIGHT: (C)2013,JPO&INPIT |
