The invention relates to a piezoelectric transformer having a piezoelectric element (1) of the length L, wherein an input voltage U.sub.in can be applied on an input side (2) for being transformed into an output voltage U.sub.out on the output side (3) according to a transformation ratio U.sub.out/U.sub.in=K.sub.u. The piezoelectric element (1) comprises multiple plies (4a, 4b, 4c) of inner electrodes, which are arranged in multiple different layers (S1, S2, S3). Each ply (4a, 4b, 4c) of inner electrodes extends along at least one predetermined sub-section of a predetermined length, wherein sub-sections of plies (4a, 4c) of a first group of layers (S1, S3) and sub-sections of plies (4b) of a second group of layers (S2) have different dimensions, so that the piezoelectric transformer satisfies the following condition: C.sub.inN.sup.2C.sub.out, wherein C.sub.in indicates the input capacitance, C.sub.out indicates the output capacitance, and N indicates the transformation ratio of the ideal transformer.

A plasma generator and a method for setting an ion ratio. In an embodiment a plasma generator includes a piezoelectric transformer suitable for ionizing a process gas, an ion separation electrode and a drive circuit suitable for applying a potential to the ion separation electrode.

A printed circuit board comprises a first mounting surface, a second mounting surface, and a piezoelectric transformer. The piezoelectric transformer has a piezoelectric substance, external electrodes, and a frame substrate. The second mounting surface has a projection region. There is a first region from a first location, where an end portion further from the output electrode out of end portions of the input electrode is projected onto the second mounting surface in the projection region, to a second location, where an end portion closer to the output electrode out of the end portions of the input electrode is projected onto the second mounting surface, the first region being a mounting allowed region where an electronic component is mounted.

A piezoelectric vibration device is provided that includes a piezoelectric transformer, a flexible board and a case. The flexible board includes an element-mounting terminal connected to an outer electrode of the piezoelectric transformer, and an external connection terminal connected to a wiring board. The case has a securing member that secures the case to the wiring board and a ceiling. When the piezoelectric vibration device is mounted on the wiring board, the securing member defines a space between the ceiling and the wiring board to accommodate the piezoelectric transformer and the flexible board. Moreover, the piezoelectric transformer is suspended to the ceiling of the case by a holding member. This configuration provides a piezoelectric vibration device with which degradation of characteristics due to causes such as displacement of the piezoelectric vibrator or fluctuations in the pressing force applied by lead terminals is minimized.

An AC adaptor is provided that includes a piezoelectric transformer, a switching circuit that is connected to an input electrode of the piezoelectric transformer and performs conversion of an input voltage by turning on and turning off switching elements. Moreover, a diode bridge and a smoothing capacitor are connected to output electrodes and a parallel circuit is connected between an input electrode and the switching circuit and includes a capacitor and a diode. In addition, a rectifying and smoothing circuit is connected in parallel with the parallel circuit and includes a diode and a capacitor. Accordingly, a power supply circuit and an AC adaptor are provided that generate an auxiliary power supply without hindering reduction in size.

In an embodiment a device includes a first housing in which a piezoelectric transformer is arranged and a second housing in which a control circuit is arranged, the control circuit configured to apply an input voltage to the piezoelectric transformer, wherein the piezoelectric transformer is configured to ionize a process medium, and wherein the device is configured to provide a circulating air operation so that the process medium is guided from the piezoelectric transformer through a catalytic converter and then back to the piezoelectric transformer and generate a non-thermal atmospheric pressure plasma.

A piezoelectric device that includes a base member having an opening therein and an upper layer supported by the base member. The upper layer includes a vibration portion at a location corresponding to the opening in the base member. The vibration portion includes a lower electrode, an intermediate electrode and an upper electrode that are spaced apart from one another in a thickness direction of the piezoelectric device. The upper layer includes a first piezoelectric layer disposed so as to be at least partially sandwiched between the lower electrode and the intermediate electrode, and a second piezoelectric layer disposed so as to overlap with the first piezoelectric layer and so as to be at least partially sandwiched between the intermediate electrode and the upper electrode. The first piezoelectric layer and the second piezoelectric layer are different in relative permittivity in the thickness direction of the piezoelectric device.

Disclosed is a digital chip-based digital driving method for a piezoelectric ceramic transformer, comprising the following steps: in a case where there is a variation in temperature and/or humidity, acquiring an output voltage of the piezoelectric ceramic transformer after rectification via a high voltage sampling circuit; sending the acquired output voltage signal to a single chip microprocessor DDS generator, comparing the acquired output voltage with a preset voltage by the single chip microprocessor DDS generator, and adjusting the frequency of the driving signal in a case where a difference between the acquired output voltage and the preset voltage exists; and adjusting a boost ratio of the piezoelectric ceramic transformer by the frequency of the driving signal, so as to output the preset voltage by the piezoelectric ceramic transformer.

The present invention is directed to a piezoelectric transformer based power converter that exhibits efficient operating point tracking ability while providing output regulation by means of simultaneous two-parameter control of the converter power stage. A regulation control stage provides the power stage a regulation control signal indicative of the difference between the measured output parameter and a set-point reference, therefore continuously controlling the gain of the converter to result in a stabilized, regulated output. Additionally, a frequency control stage simultaneously provides the power stage with a frequency control signal correlative to the difference between the current and desired operating points of the piezoelectric transformer. The power stage then translates the frequency control signal into an adjustment to the operational frequency of the input signal to the piezoelectric transformer, as to continuously drive the operating point to the desired position.

In an embodiment A device includes a first housing, in which a first device configured to generate electric fields with high field strengths is arranged and a second housing, in which a control circuit is arranged, wherein the control circuit is configured to apply an input voltage to the first device, wherein the device is configured to produce a non-thermal atmospheric pressure plasma.