| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an AC constant-voltage generator capable of increasing the speed of response by digitizing a control part without having a time constant in an output voltage detecting part and reducing a size and cost by reducing the number of parts. <P>SOLUTION: A similar waveform of an AC output voltage is detected, and the detected result is compared with a triangular wave which has a higher frequency than that of the AC output voltage to pulse an AC output. A Hi duration of each pulse of the pulsed AC output voltage is counted by using a higher frequency clock than the triangular wave. In a control means, a difference between maximum and minimum count values in one cycle of the AC output voltage is obtained, and the AC output voltage is controlled to a desired value by controlling the on-duty of a PWM signal so that the difference meets the desired value. <P>COPYRIGHT: (C)2004,JPO |
