| 摘要 |
PROBLEM TO BE SOLVED: To prevent a driving frequency of a piezoelectric transformer from becoming a spurious frequency by abnormality of a load, and to prevent heating and damage of a piezoelectric transformer element. SOLUTION: When output voltage of the piezoelectric transformer is not detected, and when an output current of the load is not detected, output is obtained from a comparator, voltage applied to a voltage to frequency conversion circuit is reduced, and the driving frequency is increased thereby. |
