A device (1) comprising an electro-ceramic component (2) which has a first electrical contact (3A), provided on a first side face (2A) of the electro-ceramic component (2) in the excitation zone (11), and a second electrical contact (3B) provided on a second side face (2B) of the electro-ceramic component (2). A sealing compound (20) is placed around the electro-ceramic component (2) so that the first electrical contact (3A) and the second electrical contact (3B) are covered by the sealing compound (20) and a free end (26) of a section (24) of the high-voltage zone (12) of the electro-ceramic component (2) projects beyond a free end (22) of the sealing compound (20).

A metering valve comprises a closable media passage leading from a media supply to a nozzle opening, wherein the medium can be applied to the workpiece in a metered manner through the nozzle opening. The metering valve is provided with a plasma generator by which the workpiece can be acted on by a plasma jet.

A device for generating a non-thermal atmospheric pressure plasma is disclosed. In an embodiment a device includes a first piezoelectric transformer configured to ignite a non-thermal atmospheric pressure plasma in a process medium and a control circuit configured to apply an input voltage to the first piezoelectric transformer and to perform a modulation of the input voltage such that the first piezoelectric transformer generates an acoustic signal as a result of the modulation.

A plasma generator is disclosed. In an embodiment a plasma generator includes a piezoelectric transformer subdivided into an input region and an output region in a longitudinal direction, wherein the piezoelectric transformer comprises an output-side end face facing away from the input region, wherein the plasma generator comprises a passive load arranged permanently in front of the output-side end face, and wherein the plasma generator is configured to generate non-thermal atmospheric-pressure plasma.

A device for producing a non-thermal atmospheric pressure plasma and a method for operating a piezoelectric transformer are disclosed. In an embodiment a device includes a piezoelectric transformer, a driver circuit configured to apply an input signal to the piezoelectric transformer and a field probe configured to measure a field strength of an electric field produced by the piezoelectric transformer at a measurement point, wherein the driver circuit is configured to adapt the input signal while taking into account measurement results of the field probe, and wherein the device is configured to produce a non-thermal atmospheric pressure plasma.

A device for generating an atmospheric-pressure plasma is disclosed. In an embodiment the device includes a piezoelectric transformer comprising an input region and an output region, wherein the input region is designed to convert an applied alternating voltage into a mechanical oscillation, wherein the output region is designed to convert a mechanical oscillation into a voltage, and wherein the output region adjoins the input region in a longitudinal direction, a contact element fastened to the piezoelectric transformer, the contact element being designed to apply the alternating voltage to the input region and a holder, wherein the contact element is connected to the holder by a form-fit connection, in such a manner that a movement of the piezoelectric transformer in the longitudinal direction, relative to the holder, is prevented.

The present invention relates to a piezoelectric transformer (1) which is divided in the longitudinal direction (L) into an input region (2) and an output region (3), wherein electrodes (4) and piezoelectric material (5) are alternately stacked in the input region (2) and an alternating voltage can be applied to the electrodes (4) in the input region (2), wherein the output region (3) comprises piezoelectric material (9) which effectuates the build-up of an electrical field when alternating voltage is applied in the input region (2), wherein the piezoelectric transformer (1) has an output-side end face (10) which faces away from the input region (2), and lateral edges (13) which extend in the longitudinal direction (L), and wherein the piezoelectric transformer (1) is designed for ionizing atoms or molecules at the output-side end face (10), thereby avoiding ionization of atoms or molecules at the lateral edges (13).

An apparatus (100) for generating a high voltage or high field strength and a component (200) for generating a high voltage or high field strength are disclosed. A means (20) that is provided in a defined area (23) of the cylindrical and dielectric housing (11) or the sleeve (202) of the component (200). The means (20) ensures that, in a space (15) of the defined area (23), between the piezoelectric transformer (1) and an inner wall (14) of the dielectric housing (11), an essentially symmetrical field distribution (16) prevails. Even with an external influence (80), the field distribution (16) is influenced in such a way that an ignition field strength in space (15) of the defined area (23) is avoided.

A device for producing a non-thermal atmospheric-pressure plasma are a method for frequency control of a piezoelectric transformer are disclosed. In an embodiment a device includes a piezoelectric transformer, an activating circuit configured to apply an AC voltage at an activating frequency to the piezoelectric transformer as an input voltage and a field probe configured to measure a field strength of an electric field produced by the piezoelectric transformer, wherein the activating circuit is configured to adapt the activating frequency based on the measurement results of the field probe such that a field strength is maximized.

A plasma generator capable of adjusting the amount of plasma generation in a simple configuration includes a control circuit controlling a frequency of an AC power supplied to a piezoelectric transformer and a control signal generation circuit providing a control signal to the control circuit. The plasma generator is configured so that the control signal output from the control signal generation circuit is appropriately adjusted. The control circuit controls the frequency of the AC power so as to bring a target value, which is set based on the control signal provided from the control signal generation circuit.