This application relates to methods and apparatus for driving a transducer with switching drivers. A driver circuit has first and second switching drivers for driving the transducer in a bridge-tied-load configuration, each of the switching drivers having a respective output stage for controllably switching the respective driver output node between high and low switching voltages with a controlled duty cycle. Each of switching drivers is operable in a plurality of different driver modes, wherein the switching voltages are different in said different driver modes. A controller controls the driver mode of operation and the duty cycle of the switching drivers based on the input signal. The controller is configured to control the duty cycles of the first and second switching drivers within defined minimum and maximum limits of duty cycles; and to transition between driver modes of operation when the duty cycle of one of the switching drivers reaches a duty cycle limit.

The use of power-efficient transmitters to establish acoustic wave energy having low undesirable harmonics is achieved by adjusting the transmitter output waveform to minimize the undesirable harmonics. In one embodiment, both the timing and slope of the waveform edges are adjusted to produce the desired output waveform having little or no second harmonics. In the embodiment, output waveform timing adjustments on the order of fractions of the system clock interval are provided. This then allows for very fine control of a coarsely produced waveform. In one embodiment, the user can select the fine tuning to match the transmitter output signal to a particular load transducer.

An electronic device (1) includes a touch panel display (2), a speaker (3), and a piezo actuator (4). The speaker (3) outputs a sound based on a first sound signal corresponding to a range of a prescribed frequency or more. The piezo actuator (4) is provided on the touch panel display (2), and is deformed in response to at least one of a second sound signal corresponding to a range of less than the prescribed frequency and a control signal for haptics feedback based on a predetermined vibration pattern to vibrate the touch panel display (2).

A dielectric elastomer vibration system includes a dielectric elastomer vibrator with a dielectric elastomer layer and a pair of electrode layers, and a power supply device producing a potential difference across the electrode layers. The vibrator exhibits various modes or regions of relationship between potential difference and deformation induced by the potential difference: a high-response region in which a relatively large deformation is induced; a low-response region of lower-potential difference in which a relatively small deformation is induced; and a low-response region of higher-potential difference in which a relatively small deformation is induced or in which a break point of the dielectric elastomer layer is included. The power supply device produces the potential difference by applying across the electrode layers a vibration signal voltage, which is generated by combining an AC voltage with a bias DC voltage corresponding to a potential difference falling in the high-response region.

The invention relates to the field of transducers, in particular linear vibration generators. It concerns a vibration generator, devices comprising such a vibration generator and a related treatment method.

A vibration generator comprising a mass, a coil, a permanent magnet and a housing, wherein the mass can be set in an oscillatory motion with respect to the housing by applying a current to the coil, and the vibration generator further comprising an axle, wherein the oscillatory motion is along the axle, and in that the mass comprises the permanent magnet and the coil is fixed to the housing.

An acoustic-electric transducer includes a connection part that has a first connection point able to contact a first contact in a terminal for processing the electrical signal, and a second connection point able to contact a second contact having a potential lower than the potential of the first contact, a microphone that transduces a sound inputted from an external source into an electrical signal, a changeover switch that switches between a non-mute state where the electrical signal is outputted to the terminal and a mute state where the electrical signal is not outputted to the terminal, and a current control circuit that makes a current flow between the first contact and the second contact until a predetermined time passes from the time when the connection part is connected to the terminal and reduces the current flowing between the first contact and the second contact after the predetermined time passes, the current control circuit being provided between the changeover switch and the connection part.

A phased array of ultrasonic transducers may create arbitrary fields that can be utilized to manipulate fluids. This includes the translation of drops on smooth surfaces as well speeding the evaporation of fluids on wetted hands. Proposed herein is the use airborne ultrasound focused to the surface of the hand. The risk is that coupling directly into the bulk of the hand may cause damage to the cellular material through heating, mechanical stress, or cavitation. Using a phased array, the focus may be moved around, thus preventing acoustic energy from lingering too long on one particular position of the hand. While some signaling may penetrate into the hand, most of the energy (99.9%) is reflected. Also disclosed are methods to couple just to the wetted surface of the hand.

Provided is a probe which transmits an ultrasonic wave to a diagnostic site and receives a reception signal which is a reflected wave. The probe includes: a plurality of transducers; a plurality of low-noise amplifying circuits respectively corresponding to the plurality of transducers; and a single differential converter which converts a control signal rising with the elapse of time to a first bias signal rising with the elapse of time and a second bias signal falling with the elapse of time to control the plurality of low-noise amplifying circuits, and the low-noise amplifying circuit includes an attenuator which attenuates: an electric signal from the transducer; a first amplifying circuit which sets the first bias signal as a bias and amplifies an output signal of the attenuator to be gradually increased with the elapse of time; a second amplifying circuit which sets the second bias signal as a bias and amplifies the output signal of the attenuator to be gradually reduced with the elapse of time; and a subtractor which subtracts an output of the first amplifying circuit and an output of the second amplifying circuit.

An system, and method are disclosed for harmonic modulation of standing wavefields for spatial focusing, manipulation, and patterning of particles, cells, powders, aerosols, colloids, and solids using a multifrequency wave source, a chamber a control module and an analysis module to generate standard wavefields useful for tissue engineering, micro fabrication, therapeutic treatment, and diagnostic tests.

A phased array of ultrasonic transducers may create arbitrary fields that can be utilized to manipulate fluids. This includes the translation of drops on smooth surfaces as well speeding the evaporation of fluids on wetted hands. Proposed herein is the use airborne ultrasound focused to the surface of the hand. The risk is that coupling directly into the bulk of the hand may cause damage to the cellular material through heating, mechanical stress, or cavitation. Using a phased array, the focus may be moved around, thus preventing acoustic energy from lingering too long on one particular position of the hand. While some signaling may penetrate into the hand, most of the energy (99.9%) is reflected. Also disclosed are methods to couple just to the wetted surface of the hand.