A device for producing a non-thermal atmospheric pressure plasma and an active space including such a device are disclosed. 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 first housing comprises a coating configured to eradicate irritant gases.

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.

There is provided a piezoelectric transformer including a first output terminal, a first piezoelectric element connected to the first output terminal, a second output terminal, a second piezoelectric element connected to the second output terminal, an input terminal, and a third piezoelectric element connected to the input terminal, wherein each of the first and second output terminals is formed to be individually connectable to a corresponding external load and outputs a voltage at a different frequency.

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.

A first rectification circuit is connected to an output side of a first piezoelectric transformer and outputs a voltage of a first polarity. A second rectification circuit is connected to an output side of the second piezoelectric transformer and outputs a voltage of a second polarity. A frequency adjustment unit is connected between the second rectification circuit and an output of the second piezoelectric transformer, and adjusts a relationship between an output voltage and a drive frequency of the second piezoelectric transformer. A driving circuit supplies a drive signal to both the first piezoelectric transformer and the second piezoelectric transformer.

The present disclosure relates to circuitry for driving a piezoelectric transducer. The circuitry may be implemented as an integrated circuit and comprises driver circuitry configured to supply a drive signal to cause the transducer to generate an output signal and active inductor circuitry configured to be coupled with the piezoelectric transducer. The active inductor circuitry may be tuneable to adjust a frequency characteristic of the output signal.

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 drive signal generating apparatus includes a transducer configured to convert electromagnetic energy of a signal received through a first port into a different type of energy, convert the different type of energy into electromagnetic energy, and transfer the converted electromagnetic energy to a second port, and a switching circuit configured to perform a gate switching operation, upon receiving a signal from the second port, to generate a drive signal.

An apparatus for generating an atmospheric pressure plasma is disclosed. In an embodiment an apparatus includes a first support element and a piezoelectric transformer supported by the first support element, wherein the piezoelectric transformer is supported at a position at which an oscillation node is formed when the piezoelectric transformer is operated at an operating frequency that is lower than its parallel resonant frequency, and wherein the piezoelectric transformer is configured to generate a non-thermal atmospheric pressure plasma.

Embodiments described herein include a resonant process monitor and methods of forming such a resonant process monitor. In an embodiment, the resonant process monitor includes a frame that has a first opening and a second opening. In an embodiment, a resonant body seals the first opening of the frame. In an embodiment, a first electrode on a first surface of the resonant body contacts the frame and a second electrode is on a second surface of the resonant body. Embodiments also include a back plate that seals the second opening of the frame. In an embodiment the back plate is mechanically coupled to the frame, and the resonant body, the back plate, and interior surfaces of the frame define a cavity.