Patent ID: 6226196
Filing Date: 2001-05-01
Classification: H01L,H02M,H05B

Abstract:
A piezoelectric transformer inverter, which drives a load by a piezoelectric transformer, comprising:a piezoelectric transformer which has an input electrode and an output electrode and which boosts an AC voltage applied to the input electrode to supply the boosted AC voltage to a load connected to the output electrode;piezoelectric transformer driving means connected to the piezoelectric transformer to drive the piezoelectric transformer, the piezoelectric transformer driving means having conductive elements, switching elements, and a phase drive circuit into which a pulse voltage signal for driving the switching elements is inputted, and converting an inputted AC voltage into an AC voltage of a substantially constant frequency lower than the inputted voltage to output to the piezoelectric transformer;phase-difference detecting means for detecting the phase difference between a driving signal for controlling the on-off operation of the switching elements and an output current or an output voltage of the piezoelectric transformer to output a control voltage corresponding to the phase difference; andfrequency controlling means for outputting a pulse voltage signal of a frequency based on the control voltage outputted from the phase-difference detecting means to the phase difference drive circuit of the piezoelectric transformer driving means so that the value of the phase difference can be a desired value.