A method for controlling a system, comprising repeatedly monitoring at least one operational characteristic of a system that includes an ultrasonic transducer, wherein the ultrasonic transducer is powered by an ultrasonic generator and is configured to drive a device at predetermined levels of vibration amplitude, and wherein the ultrasonic generator includes a controller configured to monitor operational parameters of the system; detecting a change in an operational characteristic based on a comparison of the monitored characteristic against a predetermined threshold for that characteristic; inferring a system-use criteria based on the detected change in the operational characteristic; and adapting system control by using the controller to alter the operational characteristic based on the inferred use criteria.

An ultrasonic surgical instrument includes a housing, a waveguide extending distally from the housing, an end effector coupled to the distal end of the waveguide, an ultrasonic transducer retained within the housing, and a controller. The ultrasonic transducer is coupled to the proximal end of the waveguide and configured to produce mechanical motion for transmission along the waveguide to the end effector. The controller is configured to control an amplitude of the mechanical motion of the ultrasonic transducer in accordance with at least one amplitude value. The at least one amplitude value is adjusted according to an age of the ultrasonic transducer to compensate for aging of the ultrasonic transducer. Methods for controlling the amplitude of the mechanical motion of an ultrasonic transducer to compensate for aging of the ultrasonic transducer are also provided.

The invention relates to a phaco driver system for controlling operation of an ophthalmic surgical phacoemulsification device. The phaco driver system comprises a resonant output circuit for generating a transducer voltage for driving an ultrasonic transducer of the ophthalmic surgical phacoemulsification device. Further, the phaco driver system includes a bridge unit for generating a bridge output signal for feeding the resonant output circuit, the bridge output signal being based on a composition of the first and second phase signals having a fixed mutual phase difference.

A hookah device (202) which attaches to a hookah (246). The hookah device (202) comprises a plurality of ultrasonic mist generator devices (201) for generating a mist for inhalation by a user. The hookah device (202) comprises a driver device (202) which controls the mist generator devices (201) to maximize the efficiency of mist generation by the mist generator devices (201) and optimize mist output from the hookah device (202).

An H.sub.2S sensor comprising at least one acoustic wave transducer and a film comprising a polymer matrix comprises carboxylate functional groups and lead or zinc cations. Processes for the manufacture of the sensor are also provided.

In one embodiment, a transducer controller is configured to form a drive signal with a first frequency to drive a transducer. The drive signal has a period and a half-period and drives the transducer for a first portion of the half-period. The transducer controller is configured to, for a second portion of the half-period, sense a voltage formed by the transducer, measure portions of the voltage and estimate a phase error between the first frequency and a resonant frequency of the transducer, and to adjust the first frequency to a second frequency that reduces the phase error.

A system for estimating parameters of an electromagnetic load may include an input for receiving an input excitation signal to the electromagnetic load, a broadband content estimator that identifies at least one portion of the input excitation signal having broadband content, and a parameter estimator that uses the at least one portion of the input excitation signal to estimate and output one or more parameters of the electromagnetic load.

A non-transitory computer readable medium may have stored thereon data encoding a waveform signal for playback, wherein the waveform signal is generated by implementing a discrete time model of a physical electromagnetic load that emulates a virtual electromagnetic load and modifying a raw waveform signal to generate a waveform signal for driving the physical electromagnetic load by modifying the virtual electromagnetic load to have a desired characteristic and applying the discrete time model to the raw waveform signal to generate the waveform signal for driving the physical electromagnetic load.

A resonance method for a vibration system for resonant vibration of an excitation unit having a vibrating mass includes detecting a deflection of the vibrating mass, differentiating the deflection to form a velocity of the vibrating mass; generating from the deflection and the velocity a mechanical phase position; forming from the mechanical phase position a corrected phase position by using a correction value; forming, based on the corrected phase position, an electrical angular frequency with a P-regulation; integrating the electrical angular frequency to determine an electrical phase position; forming from the electrical phase position a correction factor by using a trigonometric function; and applying the correction factor to an excitation setpoint value to generate a corrected excitation setpoint value. Also disclosed are a converter, an excitation unit having the converter, and a vibration system having the excitation unit and the vibrating mass.

A device has a piezoelectric or ferroelectric substrate on which ice is deposited. Electrodes are connected to the substrate. A vector network analyzer is connected to the electrodes and configured to determine the resonant frequency of the substrate. An excitation module including a function generator communicates with the vector network analyzer and is connected to an amplifier. The amplifier is connected to the electrodes. The excitation module uses an automatic switch to apply to the electrodes an AC electrical signal having a frequency coinciding with the resonant frequency measured in the vector network analyzer and which changes gradually as the ice melts.