| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem in the high voltage power supply device which drives a piezoelectric transformer by frequency control system that when the high voltage output is controlled in a frequency region of high boosting ratio, variation in drive frequency has a direct impact on the variation in high voltage output. Ž<P>SOLUTION: The high voltage power supply device has a configuration which can change the set up of the boosting ratio of a piezoelectric transformer according to the magnitude of the set value of output voltage. An output resistor and a boosting ratio changing means are provided at the output end of the piezoelectric transformer. A boosting ratio changing signal is input from a controller which determines a high voltage output value to the boosting ratio changing means and the boosting ratio is lowered. The deliverable output voltage range is limited when the boosting ratio is lowered, and the high voltage output can be controlled with high precision by controlling frequency variation. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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