Patent ID: 6320301
Filing Date: 2001-11-20
Classification: H01L,H05B

Abstract:
A piezoelectric-transformer inverter comprising:a piezoelectric transformer operating to transform an AC voltage applied between its primary electrodes to a transformed voltage supplied to a load connected to its secondary electrode, said piezoelectric transformer comprising:a piezoelectric substrate having a first region which is polarized in a first direction and a second region which is polarized in a second direction different than said first direction;a plurality of electrode films layered in said first region and connected together into first and second groups to form said first and second primary electrodes; andan electrode formed on an end surface of said piezoelectric substrate located substantially adjacent said second region to form said secondary electrode;a first coil and a first switching element connected to said first primary electrode of said piezoelectric transformer;a second coil and a second switching element connected to said second primary electrode of said piezoelectric transformer;a drive circuit which alternately drives said first and second switching elements such that the phase of the voltage applied between said primary electrodes is reversed cyclically; anddrive frequency control circuit which controls an AC current flowing through said load at a predetermined value by changing the operation frequency of said drive circuit;said piezoelectric transformer operating in a half wavelength mode.