A method may include measuring an electrical parameter of an electromagnetic load having a moving mass during the absence of a driving signal actively driving the electromagnetic load, measuring a mechanical parameter of mechanical motion of a host device comprising the electromagnetic load, correlating a relationship between the mechanical parameter and the electrical parameter, and calibrating the electromagnetic load across a plurality of mechanical motion conditions based on the relationship.

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).

A robotic cleaning appliance includes a housing to which is coupled a surface treatment item and a sensor assembly with first and second transducers and an acoustic interface. The first sonic transducer transmits sonic signals through an acoustic interface and out of a first acoustic opening toward a surface beneath the robotic cleaning appliance. The sonic signals reflect from the surface as corresponding returned signals received by the second sonic transducer via a second acoustic opening port of the acoustic interface. A first annular ring is defined around the first acoustic opening port and a second annular rings is defined around the second acoustic opening port. The annular ring attenuate direct path echoes between the acoustic opening ports. The first and second acoustic opening ports are coupled the first and sonic transducers, respectively, via first and second horns; and the horns are tilted from orthogonal with the surface.

The present disclosure relates to circuitry for driving a piezoelectric transducer. The circuitry comprises amplifier circuitry configured to receive a drive signal and to output an output signal, based on the drive signal, to the piezoelectric transducer, a variable capacitor configured to be coupled in series with the piezoelectric transducer, and control circuitry. The control circuitry is configured to control a capacitance of the variable capacitor to compensate for hysteresis in the piezoelectric transducer and to control a gain of the amplifier circuitry to compensate for signal attenuation caused by the variable capacitor.

The present invention relates to a haptic feedback system, and in particular to a device and method for rapidly removing residual vibration in a linear resonant actuator, the method driving the linear resonant actuator by applying a resonant frequency thereto to implement a haptic function and applying a braking signal for removing the residual vibration after the driving of the linear resonant actuator, wherein the braking signal is

a driving wave for generating the same vibration waveform as a residual vibration waveform of the linear resonant actuator, and is applied to the linear resonant actuator at a point of time when a BEMF signal of the linear resonant actuator crosses a zero point, the braking signal being applied in an opposite direction in which it is possible to cancel the residual vibration waveform of the linear resonant actuator.

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).

Embodiments described herein relate to methods and apparatuses for controlling an operation of a vibrational output system and/or an operation of an input sensor system, wherein the controller is for use in a device comprising the vibrational output system and the input sensor system. A controller comprises an input configured to receive an indication of activation or de-activation of an output of the vibrational output system; and an adjustment module configured to adjust the operation of the vibrational output system and/or the operation of the input sensor system based on the indication to reduce an interference expected to be caused by the output of the vibrational output system on the input sensory system.

Systems and methods for non-invasive fat reduction can include targeting a region of interest below a surface of skin, which contains fat and delivering ultrasound energy to the region of interest. The ultrasound energy generates a thermal lesion with said ultrasound energy on a fat cell. The lesion can create an opening in the surface of the fat cell, which allows the draining of a fluid out of the fat cell and through the opening. In addition, by applying ultrasound energy to fat cells to increase the temperature to between 43 degrees and 49 degrees, cell apoptosis can be realized, thereby resulting in reduction of fat.

A circuit for driving ultrasound transducers uses a sample-and-hold circuit to sample multiple sample periods of a transducer driving waveform, and uses the samples to modify drive parameters. Use of multiple sample periods enables independent measurement and adjustment of different portions of the transducer driving waveform to ensure mirror symmetry.

A switched resonant power amplifier system for ultrasonic transducers is disclosed. The system includes an amplifier that receives and processes a driver output signal for generating a drive signal that is provided to an ultrasonic device for controlling output of the ultrasonic device. An output control circuit receives and processes a signal related to a feedback signal generated by the ultrasonic device and a divider reference signal, and generates a compensated clock signal that is adjusted for at least one of phase and frequency differences between the received feedback signal and the divider reference signal. A compensated drive circuit receives and processes the compensated clock signal for generating the divider reference signal, and for generating the driver output signal.