Patent ID: 6044003
Filing Date: 2000-03-28
Classification: H02M,H05B,Y02B

Abstract:
A piezoelectric transformer-inverter, comprising:a piezoelectric transformer having primary electrodes and a secondary electrode;drive voltage control means for switching ON and OFF a dc voltage for generating a drive voltage having an average voltage value;piezoelectric transformer drive means for converting said drive voltage to an ac voltage and supplying said ac voltage to said primary electrodes of said piezoelectric transformer, said piezoelectric transformer converting said ac voltage at said primary electrodes thereof to a load current at said secondary electrode thereof and supplying said load current to a load connected to said secondary electrode;oscillation means for providing an oscillating signal to said piezoelectric transformer drive means;drive voltage variable means for controlling said average voltage value of said drive voltage supplied from said drive voltage control means to said piezoelectric transformer drive means in correspondence with a modulating voltage; andfrequency modulating means for changing the frequency of said oscillating signal supplied by said oscillating means in correspondence with said modulating voltage to change a boost ratio of said piezoelectric transformer such that said piezoelectric transformer is driven near its resonant frequency.