Abstract: An ultrasonic transducer device including a substrate, an edge support structure connected to the substrate, and a membrane connected to the edge support structure such that a cavity is defined between the membrane and the substrate, the membrane configured to allow movement at ultrasonic frequencies. The membrane includes a structural layer, a piezoelectric layer having a first surface and a second surface, a first electrode placed on the first surface of the piezoelectric layer, wherein the first electrode is located at the center of the membrane, a second electrode placed on the first surface of the piezoelectric layer, wherein the second electrode is a patterned electrode comprising more than one electrode components that are electrically coupled, and a third electrode coupled to the second surface of the piezoelectric layer and electrically coupled to ground.

Abstract: In accordance with an embodiment, a method of operating a piezoelectric transducer configured to transduce mechanical vibrations into transduced electrical signals at a pair of sensor electrodes includes stimulating a resonant oscillation of the piezoelectric transducer by applying at least one pulse electrical stimulation signal to the pair of sensor electrodes; detecting, at the pair of sensor electrodes, at least one electrical signal resulting from the stimulated resonant oscillation, wherein the at least one electrical signal resulting from the stimulated resonant oscillation oscillates at a resonance frequency of the piezoelectric transducer; measuring a frequency of oscillation of the at least one electrical signal resulting from the stimulated resonant oscillation to obtain a measured resonance frequency of the piezoelectric transducer; and tuning a stopband frequency of a notch filter coupled to the piezoelectric transducer to match the measured resonance frequency of the piezoelectric transducer.

Abstract: A drive control device is provided that drives an ultrasonic motor element including a piezoelectric element. The drive control device includes a voltage divider circuit unit resistor forming a voltage divider circuit unit together with an identification resistor that identifies the ultrasonic motor element; a control circuit unit connected to the voltage divider circuit unit and that sets a drive condition of the ultrasonic motor element according to a voltage of an identification signal for identifying the ultrasonic motor element; and a drive circuit unit that applies a drive voltage to the piezoelectric element based on the drive condition set by the control circuit unit.

Abstract: A structural health monitoring system based on a shape memory polymer includes a plurality of shape memory polymer buckling beam rod components, and a signal processing and structural health state abnormity warning platform. Each shape memory polymer buckling beam rod component includes an outer frame constraint, a shape memory polymer rod, and an electric signal generating element. The electric signal generating element includes piezoelectric material layers, and the signal processing and structural health state abnormity warning platform is electrically connected to the piezoelectric material layers.

Abstract: A control apparatus for a vibration type motor includes a processor or circuit that serves as a driving signal generating unit configured to generate a driving signal of the vibration type motor; and a booster circuit configured to boost the driving signal. The driving signal generating unit changes a duty ratio of the driving signal based on a driving frequency of the vibration type motor or a current flowing through the vibration type motor.

Abstract: The invention relates to a method for determining a set-point voltage for a piezoelectric actuator system to achieve a desired optical response of the piezoelectric actuator system, such as an optical power. The method is based on a mathematical model, OP(V,T,n) describing a relationship between the applied voltage and the optical response. Calibration and use of the model involves determining a transition time count value. During use, e.g. at given intervals, the model is updated based on actual values of the temperature and the transition time count value. The set-point voltage required to achieve a desired optical response is determined based on the updated model and the set-point voltage is applied to the piezoelectric actuator.

Abstract: An ultrasonic transducer array including a substrate, a membrane overlying the substrate, the membrane configured to allow movement at ultrasonic frequencies, and a plurality of anchors connected to the substrate and connected to the membrane. The membrane includes a piezoelectric layer, a plurality of first electrodes, and a plurality of second electrodes, wherein each ultrasonic transducer of a plurality of ultrasonic transducers includes at least a first electrode and at least a second electrode. The plurality of anchors includes a first anchor including a first electrical connection for electrically coupling at least one first electrode to control circuitry and a second anchor including a second electrical connection for electrically coupling at least one second electrode. The ultrasonic transducer array could be either a two-dimensional array or a one-dimensional array of ultrasonic transducers.

Abstract: The present disclosure relates to circuitry for driving a piezoelectric transducer to generate an audio output. The circuitry comprises pre-processor circuitry configured to process an input audio signal to generate a processed signal; driver circuitry coupled to the pre-processor circuitry and configured to generate a drive signal, based on the processed signal, for driving the piezoelectric transducer; and processor circuitry configured to determine a resonant frequency of the piezoelectric transducer. The pre-processor circuitry is configured to process the input audio signal based on the determined resonant frequency so as to generate the processed signal.

Abstract: A blade seal for sealing a gap between a first aircraft component and a second aircraft component, including a flexible seal member having a first end for attaching to the first aircraft component and a second end for extending towards the second aircraft component, a sensor and an actuator directly coupled to the flexible seal member. The sensor is configured to detect deformation of the flexible seal member and send a signal to the actuator in response to the deformation, and the actuator is configured to impart a load on the flexible seal member and to activate only in response to the signal received directly from the sensor by the actuator to counter the detected deformation of the flexible seal member.

Abstract: Aspects of the subject technology relate to electronic devices having speakers and airflow sensors for the speakers. In one or more implementations, the airflow sensor may be formed, in part, by a mesh structure that spans a port in a housing of the electronic device. In one or more implementations, the airflow sensor may be formed, in part, by an exposed portion of a conductive trace of the speaker.

Abstract: A piezoelectric element device includes: a substrate including a plurality of vibrating portions having a first vibrating portion and a second vibrating portion; a piezoelectric element group in which a plurality of piezoelectric elements having a first piezoelectric element and a second piezoelectric element provided in the plurality of vibrating portions are coupled in parallel to each other; a plurality of load detectors having a first load detector including the first vibrating portion and the first piezoelectric element provided in the first vibrating portion and a second load detector including the second vibrating portion and the second piezoelectric element provided in the second vibrating portion; and a resin layer covering the piezoelectric element group.

Abstract: A first power supply member and a second power supply member are arranged on the same side of a first member in a thickness direction of an actuator. The first power supply member includes a first external connection terminal. The second power supply member includes a second external connection terminal. The first external connection terminal and the second external connection terminal are arranged on the same positions in the thickness direction. A second insulating layer is arranged between the second power supply member and a frame body. A far end side portion on an opposite side to a side, on which the first external connection terminal protrudes, in the first power supply member is bent toward the frame body to be electrically connected with the frame body.

Abstract: A head chip, a liquid jet head, and a liquid jet recording device each capable of increasing pressure generated while achieving power saving are provided. The head chip according to an aspect of the present disclosure includes a flow channel member having a pressure chamber containing liquid, an actuator plate which is stacked on the flow channel member in a state of being opposed to the pressure chamber in a first direction, a drive electrode which is formed on a surface facing to the first direction in the actuator plate, and which is configured to deform the actuator plate in the first direction to change a volume of the pressure chamber, and a non-drive member which is stacked at an opposite side to the flow channel member across the actuator plate in the first direction, and which is configured to limit a displacement of the actuator plate toward an opposite side to the flow channel member in the first direction.

Abstract: A method is provided for transmitting transmission data from a sensor controller that detects a pen to the pen through a sensor electrode group. The pen includes a pen tip electrode arranged near a pen tip, and an analog circuit that detects edges of a signal led to the pen tip electrode. The pen also includes a digital circuit that performs a correlation operation of an output signal of the analog circuit and known patterns to detect the transmission data. The sensor controller is configured to generate a pulse signal representing the transmission data. The sensor controller is configured to transmit the pulse signal, by using a main signal and a sub signal of the pulse signal so as to enhance the edges, thereby transmitting the transmission data through the sensor electrode group.

Abstract: A handheld controller includes a housing and a first vibration source disposed in the housing and characterized by a first phase. The handheld controller also includes a second vibration source disposed in the housing and characterized by a second phase different than the first phase and a controller disposed in the housing, coupled to the first vibration source and the second vibration source, and configured to vary at least one of the first phase or the second phase.

Abstract: Examples of portable electronic devices including a piezo actuated vibrator for providing tactile feedback to the user are described. Portable electronic devices according to the present disclosure may include tactile feedback devices, which may be driven by a piezoelectric actuator/vibrator that is operatively coupled to or embedded into the housing of a portable electronic device. In some examples, the housing of the electronic device itself can be made of piezoelectric ceramic material. The piezoelectric element may be coupled to the housing of the product to cause the housing to deflect and/or vibrate. In some examples, the housing of the portable electronic device, which may be a portable media player device, may be configured for placement directly or indirectly in contact with the user's skin such that vibrations of the housing may be felt directly (without audible feedback) by the user.

Abstract: A control console for a powered surgical tool. The console includes a transformer that supplies the drive signal to the surgical tool. A linear amplifier with active resistors selectively ties the ends of the transformer primary winding between ground and the open circuit state. Feedback voltages from the transformer windings regulate the resistances of the active resistors.

Abstract: A device includes an electrical circuit and a mutual-capacitance sensing circuit coupled to the electrical circuit. The mutual-capacitance sensing circuit includes mutual-capacitance sensing electrodes including a transmitter electrode and receiver electrode. The device also includes a conductive overlay over the mutual-capacitance sensing electrodes. The mutual-capacitance sensing circuit is configured to detect deflection of a portion of the conductive overlay relative to the mutual-capacitance sensing electrodes. The receiver electrode has a shape with an inner edge, and the transmitter electrode has a shape with an outer edge that is at least partially surrounded by the inner edge of the receiver electrode.

Abstract: There is presented a method for driving a piezoelectric device and an atomizer for atomizing a fluid, and an atomization method for a fluid using a piezoelectric device; the atomizer employs a piezoelectric device and circuitry that uses a switching voltage across the piezoelectric device at an operating frequency; sensing a sensed voltage corresponding to a phase of the piezoelectric device; and responsive to whether the sensed voltage is in phase or out of phase relative to the switching voltage, changing the operating frequency provided to the piezoelectric device, and the changing is one of: increasing the operating frequency by a first value, or decreasing the operating frequency by a second value.

Abstract: A resonant frequency tracker for driving an electromagnetic load with a driving signal may include a signal generator configured to generate a waveform signal at a driving frequency for driving an electromagnetic load and control circuitry. The control circuitry may be configured to, during driving of the electromagnetic load by the waveform signal or a signal derived therefrom, receive a current signal representative of a current associated with the electromagnetic load and a second signal representative of a second quantity associated with the electromagnetic load, the second quantity comprising one of a voltage associated with the electromagnetic load or a back electromotive force of the electromagnetic load. The control circuitry may be further configured to calculate a phase difference between the current signal and the second signal, determine a frequency error of the waveform signal based on the phase difference, and control the driving frequency based on the frequency error.

Abstract: An apparatus and a method for inspecting a semiconductor includes a water tank which includes a housing, an interior of which is filled with a liquid, and a support block which provides a settling surface for an inspection object inside the housing. A plurality of signal generators are installed on a bottom surface of the housing, and output a frequency signal in a direction in which the inspection object is located. A power supply operates the signal generators. A probe is placed above the inspection object, and a receiver which operates with the probe and is attached to a bottom surface of the support block. Foreign matter remaining on the inspection object are removed, using a plurality of frequency signals which are output by the plurality of signal generating units.

Abstract: Control consoles and methods for supplying a drive signal to a surgical tool are provided. The control console comprises a transformer with primary and secondary windings. The primary winding receives an input signal from a power source and induces the drive signal in the secondary winding to supply the drive signal to the surgical tool. A first current source comprising a leakage control winding is coupled to a path of the drive signal. The primary winding induces a first cancellation current in the leakage control winding to inject into the path of the drive signal to cancel leakage current. A sensor coupled to the path of the drive signal outputs a sensed signal to provide feedback related to leakage current. The sensor may connect to a second leakage current cancellation source and/or a fault detection stage. The power source may be variable and may also energize the second current source.

Abstract: A piezoelectric motor includes: a stator having an elastic body, a piezoelectric element and a sliding member adhesively attached to the elastic body; a rotor having an annular member, which includes a disc spring portion and a basic body portion in contact with the sliding member, and a fixture portion to which the annular member is fixed; and a shaft that rotates with the rotor, wherein the disc spring portion of the annular member is fixed to the fixture portion which is fixed to the shaft.

Abstract: The present disclosure relates to driver circuitry for driving a piezoelectric transducer. The circuitry comprises: a power supply; a reservoir capacitance; switch network circuitry; and control circuitry. The control circuitry is configured to control operation of the switch network circuitry so as to charge the reservoir capacitance from the power supply and to transfer charge between the reservoir capacitance and the piezoelectric transducer.

Abstract: A driving circuit and a driving method are provided. The driving circuit includes a charging circuit and a discharging circuit. The charging circuit is configured to receive an input voltage to charge the piezoelectric load. The piezoelectric load discharges electricity through the discharging circuit. Operation states of the charging circuit and the discharging circuit are controlled. During a first operation interval of an operation period, the charging circuit charges the piezoelectric load so that a power supply voltage signal provided to the piezoelectric load corresponds to the reference voltage in a first interval. During a second operation interval of the operation period, the piezoelectric load discharges electricity through the discharging circuit so that the power supply voltage signal corresponds to the reference voltage in a second interval. The driving circuit according to the present disclosure requires a few switches, thereby facilitating circuit integration.

Abstract: There is provided a vibration damping material capable of exhibiting excellent vibration damping performance and of reducing its own weight while having high rigidity. The vibration damping material of the present invention used so as to be installed on a panel of a vehicle includes a viscoelastic layer and a constraining layer provided on one surface of the viscoelastic layer, wherein a relationship between a strain ?a and a strain ?b is 0<?a/?b<1, the strain ?a being a strain on a surface of the constraining layer on the opposite side to the viscoelastic layer, and the strain ?b being a strain on a surface of the constraining layer on a side in contact with the viscoelastic layer.

Abstract: Systems, devices and methods for the management of glucose levels in the body of patient featuring user interface input mechanisms configured to provide haptic feedback to the user are provided.

Abstract: The present disclosure relates to circuitry for driving a piezoelectric transducer. The circuitry comprises pre-processor circuitry configured to process an input signal to generate a processed signal; driver circuitry coupled to the pre-processor circuitry and configured to generate a drive signal, based on the processed signal, for driving the piezoelectric transducer; and processor circuitry configured to determine a resonant frequency of the piezoelectric transducer. The pre-processor circuitry is configured to process the input signal based on the determined resonant frequency so as to generate the processed signal.

Abstract: There are provided a characteristic table generation system and so on capable of enhancing the convenience of the user.

Abstract: Operating a bi-directional double-base bipolar junction transistor (B-TRAN). One example is a method comprising: conducting a first load current from an upper terminal of the power module to an upper-main lead of the transistor, through the transistor, and from a lower-main lead of the transistor to a lower terminal of the power module; and then responsive assertion of a first interrupt signal, interrupting the first load current from the lower-main lead to the lower terminal by opening a lower-main FET and commutating a first shutoff current through a lower-control lead the transistor to the lower terminal; and blocking current from the upper terminal to the lower terminal by the transistor.

Abstract: An optical element driving mechanism has an optical axis and includes a fixed portion, a movable portion, and a driving assembly. The movable portion is movable relative to the fixed portion. The driving assembly drives the movable portion to move relative to the fixed portion. The driving assembly moves in a first direction to move the movable portion in a second direction, wherein the first direction is different from the second direction.

Abstract: The invention relates to a method and an actuator system for determining and applying a voltage to a piezoelectric actuator (PEA) to achieve a given setpoint displacement. The method involves determining a relation dcal(V) between a PEA displacement measure (d) and voltage (V) and a relation ttcal(V) between transition time (tt) and voltage and combining the determined relations to calculate a relation d(tt) between the displacement measure and transition time during an initial calibration procedure. This relation is characteristic for the PEA, and by determining a new relation ttnew(V) after repeated biasing of the PEA, a compensated relation dc(V) can be calculated by substituting ttnew(V) in the calculated d(tt). The compensated relation dc(V) compensates for piezo creep effects due to the wear and can be used to determine the voltage to be applied directly, or be used in other compensation algorithms.

Abstract: A humidifier includes a first housing removably connected to a second housing that includes the majority of the electrical components of the humidifier. The first housing includes a first air inlet for accepting air; a first air outlet; a central chamber for holding water; a piezoelectric transducer installed in the central chamber for atomizing water; and a first electrical connector electrically connected to the piezoelectric transducer. The first housing is configured to discharge humidified air from the first air outlet.

Abstract: A hearing system is disclosed comprising a support unit, and at least one abutment unit, wherein the support unit supports the at least one abutment unit. The at least one abutment unit has a contact surface. The support unit is configured to be placed at a user's head such that the contact surface of the at least one abutment unit contacts the user's head in an area surrounding one of the user's ears, in particular, in an area of one of the user's mastoid bones. The at least one abutment unit comprises a contact element, the contact element being configured to transmit vibrations generated by a vibration generating unit towards the contact surface. The contact element is made of a fiber-reinforced plastic material.

Abstract: Circuitry for estimating a displacement of a piezoelectric transducer in response to a drive signal applied to the piezoelectric transducer, the circuitry comprising: monitoring circuitry configured to be coupled to the piezoelectric transducer and to output a sense signal indicative of an electrical signal associated with the piezoelectric transducer as a result of the drive signal; wherein the circuitry is configured to generate a difference signal based on the drive signal and the sense signal; and wherein the circuitry further comprises processing circuitry configured to apply at least one transfer function to the difference signal to generate a signal indicative of the displacement of the piezoelectric transducer.

Abstract: An ultrasonic apparatus includes a transmitting circuit, an ultrasonic transducer, a receiving circuit, and a capacitance measuring circuit. The ultrasonic transducer is a three-terminal ultrasonic transducer that includes a transmitting electrode, a receiving electrode, and a common electrode. The transmitting circuit outputs a driving signal to the transmitting electrode to cause the ultrasonic transducer to transmit ultrasonic waves. The receiving circuit receives a receive signal from the receiving electrode. The capacitance measuring circuit is electrically connected to the receiving electrode to measure the electrostatic capacitance of the ultrasonic transducer.

Abstract: Systems and methods for the ultrasonic disruption of biofilm and algae growth on underwater structures utilize an ultrasonic actuator that produces a natural frequency in the ultrasonic range. In some embodiments, the ultrasonic actuator includes one or more piezoelectric transducers.

Abstract: A driving control apparatus controls an actuator that relatively moves a vibrator and a contact body contacting the vibrator, the vibrator being made to generate vibration by applying a first signal and a second signal having a phase difference. The driving control apparatus includes at least one processor or circuit configured to execute a plurality of tasks including a first determining task configured to determine the phase difference, and a second determining task configured to determine a voltage amplitude of power supplied to the actuator so that the voltage amplitude decreases as an absolute value of the phase difference decreases.

Abstract: A device includes a superconductor layer and a piezoelectric layer positioned adjacent to the superconductor layer. The piezoelectric layer is configured to apply a first strain to the superconductor layer in response to receiving a first voltage that is below a predefined voltage threshold and to apply a second strain to the superconductor layer in response to receiving a second voltage that is above the predefined voltage threshold. While the device is maintained below a superconducting threshold temperature for the superconductor layer and is supplied with current below a superconducting threshold current for the superconductor layer, the superconductor layer is configured to 1) operate in a superconducting state when the piezoelectric layer applies the first strain to the superconductor layer and 2) operate in an insulating state when the piezoelectric layer applies the second strain to the superconductor layer.

Abstract: An electronic component package includes a lid, a first layer, a second layer disposed between the first layer and the lid and configuring a first frame, a third layer disposed between the second layer and the lid and configuring a second frame, a bonding member bonding the third layer to the lid, and a via wire electrically coupled to the lid and penetrating the second frame, in which, when an inner diameter of a first corner portion of the first frame is denoted by R1 and an inner diameter of a second corner portion of the second frame overlapping the first corner portion in a plan view is denoted by R2, R1<R2, and an inner surface of the second corner portion protrudes more than an inner surface of the first corner portion in a cross-sectional view.

Abstract: An electromechanical actuator for electrical flight controls of an aircraft, the actuator comprising a transmission shaft, four electromechanical conversion members, each having a respective stator and rotor secured to the transmission shaft, and four control systems, each dedicated to respective ones of the electromechanical conversion members. The stator has teeth and windings surrounding at least one tooth, whereas the rotor is provided with permanent magnets. Each electromechanical conversion member is a flux-concentrating member and each winding is concentric and has a single layer. The electromechanical actuator is intended in particularly for controlling a hydraulic actuator via a mechanical transmission within an electrical flight control device of an aircraft.

Abstract: An inertia drive motor is disclosed which includes an element to be driven, and a stator, the stator having: an elastic frame, at least one friction element arranged on the elastic frame and configured to be brought into frictional contact with the element to be driven, and a first electromechanical actuator and a second electromechanical actuator, which are configured to cause, by interaction, a deformation of the elastic frame, upon excitation with different excitation voltages having a sawtooth signal, so as to displace the at least one friction element for driving the element to be driven by stick-slip contact with the friction element.

Abstract: A motion control system and method for controlling a stick-slip piezo motor includes an electronic controller and an analog driver for moving a mechanical device. When operating in a digital circuit mode, an electronic controller controls a digital-to-analog converter for moving the stick-slip piezo motor at a low speed. When operating in a faster analog circuit mode, the electronic controller, via an analog driver, operates to control an analog hardware circuit to move the stick-slip piezo motor at a high speed. The electronic controller operates in the digital circuit mode at start-up of the piezo motor.

Abstract: According to one embodiment, a magnetic disk device including a disk, a head that writes data to the disk and reads data from the disk, an actuator that is rotationally driven and controls movement of the head mounted above the disk, a microactuator that is mounted on the actuator and finely swings the head in a radial direction of the disk by a piezoelectric element that extends and contracts when a drive voltage based on a bias voltage is applied to the piezoelectric element, and a controller that switches the bias voltage according to an operation state during an access process.

Abstract: An ultrasonic apparatus includes an ultrasonic transducer, a transmitting circuit, a receiving circuit, a Q-factor measuring circuit, and a frequency measuring circuit. The ultrasonic transducer is a three-terminal ultrasonic transducer that includes a transmitting electrode, a receiving electrode, and a common electrode. The transmitting circuit outputs a driving signal to the transmitting electrode to cause the ultrasonic transducer to transmit ultrasonic waves. The receiving circuit receives a receive signal from the receiving electrode. The frequency measuring circuit measures a resonant frequency of the ultrasonic transducer from a reverberation signal in the receive signal. The Q-factor measuring circuit measures a Q factor of the ultrasonic transducer from the reverberation signal in the receive signal.

Abstract: Provided are a fluid control device capable of operating a piezoelectric pump even in a case where a low discharge pressure or a slow pressurization speed is required and a sphygmomanometer including the fluid control device. A fluid control device includes a piezoelectric pump that includes a piezoelectric element, a self-excited circuit that performs, upon application of a driving power source voltage thereto, self-excited oscillation to drive the piezoelectric element, a switch that interrupts the driving power source voltage for the self-excited circuit, and a control circuit that changes an on duty ratio of the self-excited circuit by switching between states of the switch at a predetermined switching frequency and a predetermined on duty ratio.

Abstract: A vibration device is provided that includes a vibration element with a piezoelectric vibrator and a driving device that causes the vibration element to vibrate. The vibration element includes a translucent body and the piezoelectric vibrator is electrically coupled to the driving device. The driving device includes a first circuit that applies an electric signal to the piezoelectric vibrator to render the vibration element in a resonant state, a second circuit that applies an electric signal to the piezoelectric vibrator according to a feedback signal output from the piezoelectric vibrator, and a switch that switches coupling between the first circuit and the piezoelectric vibrator and coupling between the second circuit and the piezoelectric vibrator at a certain timing.

Abstract: A vehicle system includes: an olfaction sensor comprising: a blower configured to draw air from a passenger cabin through an inlet; a sensor located downstream of the inlet and including one or more proteins configured to measure an amount of a chemical in the air passing the sensor; and a purge source configured to selectively flows a purge gas into the sensor; and a control module configured to selectively take one or more remedial actions based on the amount of the chemical in the air.

Abstract: A piezoelectric motor includes a driven member rotating around a rotation axis, and a plurality of piezoelectric vibrators rotating the driven member by transmitting drive forces to the driven member. The plurality of piezoelectric vibrators includes a first piezoelectric vibrator and a second piezoelectric vibrator at a larger distance from the rotation axis than the first piezoelectric vibrator. The control method for the driven member includes, for acceleration of the driven member, rotating the driven member by the drive force of the second piezoelectric vibrator when a rotation velocity of the driven member is lower than a first velocity, and rotating the driven member by the drive force of the first piezoelectric vibrator when the rotation velocity of the driven member is equal to or higher than the first velocity.

Abstract: The present disclosure relates to circuitry for driving a piezoelectric transducer based on an input signal. The circuitry comprises: primary driver circuitry configured to receive the input signal and to output a primary driving signal to the piezoelectric transducer based on the input signal; and secondary driver circuitry configured to receive an error signal indicative of an error between the input signal and the primary driving signal and to output a secondary driving signal to the piezoelectric transducer based on the error signal, wherein the primary driver circuitry and the secondary driver circuitry both comprise switching converter circuitry.