This application relates to methods and apparatus for driving a transducer with switching drivers where the switching driver has an output bridge stage for switching an output node between switching voltages and a modulator for controlling the duty cycle of the output bridge stage based on an input signal. The switching driver also includes a voltage controller for providing the switching voltages which is operable to provide different switching voltages in different driver modes. A controller is provided to control the driver mode of operation and the duty cycle of the switching driver based on the input signal, and the controller is configured to transition from a present driver mode to a new driver mode by controlling the voltage controller to provide the switching voltages for the new mode and controlling the modulator to vary the duty cycle of the output bridge stage. The change in duty cycle is controlled such that there is no substantial discontinuity in switching ripple due to the mode transition.

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.

Apparatus, systems, and methods for acoustic transmission via tubular are provided. A transceiver comprises a piezoelectric transducer; a switch coupled to the piezoelectric transducer; a charge mode receiver coupled to the switch; and a transmitter coupled to the switch.

A wearable device that is capable of harvesting kinetic energy from wrist motions using piezoelectric and/or electromagnetic energy harvesters is disclosed. A first part of the device is worn on the user and second part of the device is movable against the second part to accentuate the frequency of movements.

A method for sensing an abnormality of a piezoelectric drive device is a method for sensing a vibration abnormality of the piezoelectric drive device having a substrate and thin-film piezoelectric elements placed on the substrate and controlling amplitude of the piezoelectric elements using a drive control signal, and the method includes sensing the vibration abnormality by a drive voltage corresponding to the drive control signal.

A vibration device includes a cylindrical body including an opening, a light-transmissive cover joined to the cylindrical body, a piezoelectric element directly or indirectly joined to the cylindrical body and including first and second main surfaces, and a power feeder joined to the piezoelectric element. The power feeder includes a substrate including first and second surfaces, first and second power feeding electrodes on the first surface or the second surface, and first and second external connection electrodes. The power feeder sandwiches the piezoelectric element in a thickness direction, and the first and second power feeding electrodes are joined to the first main surface or the second main surface of the piezoelectric element. Portions of the substrate, which are not located on the first and second main surfaces of the piezoelectric element, are bent to sandwich the piezoelectric element.

Illustrative embodiments provide an electrostatic actuator and methods of making and operating an electrostatic actuator. The electrostatic actuator comprises a framework and a plurality of electrodes. The framework comprises walls defining a plurality of cells forming an array of cells. The plurality of electrodes comprise an electrode in each cell in the plurality of cells. A gap separates the electrode in each cell from the walls of the cell. The framework is configured to contract in response to an electrical signal applied between the framework and the plurality of electrodes.

A tactile reproduction device, a method for driving the same, and a tactile reproduction apparatus. Tactile reproduction device may simulate textures to implement tactile reproduction. tactile reproduction device includes a plurality of piezoelectric units, includes: first electrode, piezoelectric section, and second electrode which are laminated, wherein the second electrode includes: first comb electrode and second comb electrode; the first comb electrode includes: a plurality of first comb-teeth electrodes and a first comb-shank electrode connecting the plurality of first comb-teeth electrodes; the second comb electrode includes: a plurality of second comb-teeth electrodes and a second comb-shank electrode connecting the plurality of second comb-teeth electrodes; the plurality of first comb-teeth electrodes and the plurality of second comb-teeth electrodes are mutually intersected; the first electrode includes a plurality of electrode units which are not connected to each other. The present disclosure is applicable to the production of tactile reproduction devices.

A method may include controlling commutation of a plurality of switches of an output stage comprising the plurality of switches in order to transfer charge between an energy storage device and a load to generate an output voltage across the load as an amplified version of an input signal, wherein the load comprises capacitive energy storage and controlling the power converter in order to regulate a cumulative electrical energy present in the system at an energy target, wherein the power converter is configured to transfer electrical energy from a source of electrical energy coupled to an input of the power converter to the energy storage device coupled to the output of the power converter and configured to store the electrical energy transferred from the source of electrical energy.

A light scanning apparatus includes a light source configured to intermittently emit light based on an irradiation timing signal; a mirror configured to reflect the light emitted by the light source; an actuator configured to cause the mirror to be deflected based on drive signals; a sensor configured to output a signal according to deflection of the mirror; an irradiation timing adjusting-unit configured to adjust the irradiation timing signal based on the output signal of the sensor; and an irradiation timing storage configured to store the adjusted irradiation timing signal.