| 摘要 |
PROBLEM TO BE SOLVED: To widen the range of power supply voltage in with which a piezoelectric transformer and be driven with high efficiency. SOLUTION: This piezoelectric transformer comprises a power supply 1, a coil 4 connected between the first primary electrode of a piezoelectric transformer 8 and the positive electrode of the power supply 1, a transistor 6 connected between the first primary electrode and the negative electrode of the power supply 1, a transistor 2 and a coil 3 connected between the second primary electrode of the piezoelectric transformer 8 and the positive electrode of the power supply 1, a transistor 5 connected between the second primary electrode and the negative electrode of the power supply means for detecting the amplitude of a drive voltage generated between the second primary electrode and the negative electrode of the power supply 1, and means for reducing the amplitude of a drive voltage which is inputted to the piezoelectric transformer 8 by interrupting the positive electrode of the power supply 1 and the second coil 3 using the second transistor 2, when the amplitude of the drive voltage thus detected exceeds a specified level. |
