A system may include a signal generator configured to generate a raw waveform signal and a modeling subsystem configured to implement a discrete time model of an electromagnetic load that emulates a virtual electromagnetic load and further configured to modify the raw waveform signal to generate a waveform signal for driving the electromagnetic load by modifying the virtual electromagnetic load to have a desired characteristic, applying the discrete time model to the raw waveform signal to generate the waveform signal for driving the electromagnetic load, and applying the waveform signal to the electromagnetic load.

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.

An acoustophoretic system is controlled and driven to attain a desired level of performance. An RF controller and a driver provide a frequency and power to an acoustic transducer, which can be implemented as a piezoelectric element, which presents a reactive load or a complex load. A controller implements a control technique for efficient transducer operation. The control technique can locate a frequency for operation that is at a reactance minimum or maximum for the system to produce a modal pattern and to provide efficient operation of the transducer. A method of detecting a minimum or maximum reactance in a acoustophoretic system used to trap, separate, deflect, cluster, fractionate or otherwise process particles or secondary fluids or tertiary fluids in a primary fluid and utilizing the frequency of the detected reactance to operate the acoustophoretic system.

This disclosure relates to systems and methods for ultrasonic lens cleaning. In an example, an ultrasonic lens cleaning system can be configured to apply sequences that include at least one driver signal adapted to drive a transducer adaptively coupled to a top cover. The transducer can be excited based on the sequences to vibrate the top cover to remove a contaminant from a surface of the top cover. The applying of the sequences can include applying a first sequence to the transducer based on a first set of sequence parameters, applying a second sequence to the transducer based on a second set of sequence parameters, and applying a third sequence to the transducer based on a third set of sequence parameters.

A galvanically isolated voltage sensor is provided which includes a mechanically integral piezoelectric transformer assembly coupled to a modulation circuit. The modulation circuit receives a source voltage signal to be measured and modulates that signal at a frequency equal to a resonance frequency of the transformer assembly and transmits the modulated to signal to the transformer assembly. The transformer assembly generates an output signal that is identical to the modulated signal subject to the transformer gain. The output signal is then demodulated and filtered so as to recreate the source voltage signal for analysis.

A measuring device determines a fluid variable with a control device, a measuring tube and a first vibration transducer arranged at the measuring tube. The first vibration transducer contains a vibration element. The vibration element has a vibration body, a first electrode on the measuring tube side and a second electrode averted from the measuring tube. The first electrode extends over a first end face of the vibration body. The second electrode extends to a second end face that lies opposite the first end face. A respective conductive contact element contacts the first electrode at a first end face and the second electrode at a second end face electrically and mechanically such that the vibration element is supported by the contact elements. A voltage between the first and second electrodes can be varied through the vibration element to excite a guided wave in a side wall of the measuring tube.

A method and an apparatus to improve the precision and reproducibility of particle size analysis by laser diffraction is presented. Powder particles are typically prepared for laser diffraction testing using an ultra-sound bath which will disperse particle agglomerates and allow a precise measurement. However, the precision and reproducibility of agglomerate dispersion is affected by ultra-sound probe wear, corrosion and age. Differences in sonication performance can be compensated by voltage adjustments to the ultra-sound probe, leading to substantial improvements in the precision and reproducibility of particle size determination.

For a resonator system such as a (haptic) LRA, a methodology for resonant frequency (F0 tracking/control with continuous resonator drive, based on estimating back-emf, including estimating resonator resistance based at least in part on the sensed resonator drive signals, with back-emf estimated based at least in part on the sensed resonator drive signals and the estimated resonator resistance. A phase difference is detected between the resonator drive signals, and the estimated back-emf signals, generating control for resonator drive frequency, which can be used to iteratively adjust the resonator drive frequency until phase coherent with the estimated back-emf signals (F0 lock), such as for driving the resonator at or near a resonant frequency. An amplitude control loop can be used to iteratively adjust resonator drive amplitude based on a difference between estimated back-emf and a target back-emf derived from a rated back-emf and the resonator frequency resonant frequency.

A linear vibrator includes a shell, a first elastic member, a second elastic member, a weight, a magnet, and a coil. The shell has a receiving space, and first and second internal surfaces. The first elastic member and the second elastic member respectively contact the first internal surface and the second internal surface. The weight is mounted between the first elastic member and the second elastic member and has a receiving chamber. The magnet is mounted in the receiving chamber. The coil is located in the receiving chamber to cover the magnet and mounted on the shell. The linear vibrator is used for amplitude control and is compensated for by a printed circuit on the shell. The linear vibrator is small size, of simple structure, and has better performance.

An electric measurement circuit possesses an electrical reaction leg for forming an oscillator from a resonator, and furthermore possesses a measurement leg the input of which is supplied by the electrical reaction leg. The measurement leg contains an adjustable phase shifter so that an additional excitation force that is applied to the resonator in the measurement leg can be adjusted in phase quadrature with respect to an excitation force that is applied to the resonator in the electrical reaction leg. Such an electrical measurement circuit is particularly suitable for forming a photoacoustic gas detector.