2779 results about "Fundamental frequency" patented technology

A new current loop control system method is proposed for a single-phase grid-tie power conditioning system that can be used under a standalone or a grid-tie mode. This type of inverter utilizes an inductor-capacitor-inductor (LCL) filter as the interface in between inverter and the utility grid. The first set of inductor-capacitor (LC) can be used in the standalone mode, and the complete LCL can be used for the grid-tie mode. A new admittance compensation technique is proposed for the controller design to avoid low stability margin while maintaining sufficient gain at the fundamental frequency. The proposed current loop controller system and admittance compensation technique have been simulated and tested. Simulation results indicate that without the admittance path compensation, the current loop controller output duty cycle is largely offset by an undesired admittance path. At the initial simulation cycle, the power flow may be erratically fed back to the inverter causing catastrophic failure. With admittance path compensation, the output power shows a steady-state offset that matches the design value. Experimental results show that the inverter is capable of both a standalone and a grid-tie connection mode using the LCL filter configuration.

A system and method are provided for detecting emotional states using statistics. First, a speech signal is received. At least one acoustic parameter is extracted from the speech signal. Then statistics or features from samples of the voice are calculated from extracted speech parameters. The features serve as inputs to a classifier, which can be a computer program, a device or both. The classifier assigns at least one emotional state from a finite number of possible emotional states to the speech signal. The classifier also estimates the confidence of its decision. Features that are calculated may include a maximum value of a fundamental frequency, a standard deviation of the fundamental frequency, a range of the fundamental frequency, a mean of the fundamental frequency, and a variety of other statistics.

Natural-sounding synthesized speech is obtained from pieced elemental speech units that have their super-class identities known (e.g. phoneme type), and their line spectral frequencies (LSF) set in accordance with a correlation between the desired fundamental frequency and the LSF vectors that are known for different classes in the super-class. The correlation between a fundamental frequency in a class and the corresponding LSF is obtained by, for example, analyzing the database of recorded speech of a person and, more particularly, by analyzing frames of the speech signal.

A system and method is provided for locating objects using RFID tags. The system and method uses an RFID reader and a distance calculator to efficiently and accurately determine the location of objects that include an RFID tag. The RFID reader transmits a plurality of signals to the RFID tag, with the plurality of signals having different fundamental frequencies. In response, the RFID tag backscatter modulates the plurality of transmitted signals to create a plurality of backscatter modulated signals. The RFID reader receives and demodulates the plurality of backscatter modulated signals. The distance calculator determines the phase of the plurality of backscatter modulated signals and determines a rate of change of the phase in the backscatter modulated signals with respect to the rate of change in the fundamental frequency of the transmitted signals and uses this information to calculate the distance to the RFID tag.

Several embodiments of medical ultrasound handpieces are described each including a medical ultrasound transducer assembly. An embodiment of a medical ultrasound system is described, wherein the medical ultrasound system includes a medical ultrasound handpiece having a medical ultrasound transducer assembly and includes an ultrasonically-vibratable medical-treatment instrument which is attachable to a distal end of the transducer assembly. An embodiment of a medical ultrasound system is described, wherein the medical ultrasound system has a handpiece including a medical ultrasound transducer assembly and including a housing or housing component surrounding the transducer assembly. A method for tuning a medical ultrasound handpiece includes machining at least a distal non-threaded portion of an instrument-attachment stud of the transducer assembly to match a measured fundamental frequency to a desired fundamental frequency to within a predetermined limit. A method for making a medical ultrasound transducer assembly determines acceptable gains for gain stages of the transducer assembly.

A combined matching and harmonic rejection circuit with increased harmonic rejection provided by a split resonance for one or more of the capacitive or inductive elements of the circuit. At a fundamental frequency, the circuit comprises an inductive series arm with capacitive shunt arms. The capacitance of a shunt arm may be provided by two or more parallel paths, each having a capacitor and an inductor in series so that, in addition to providing the effective capacitance necessary for impedance matching at the fundamental frequency, two separate harmonics represented by the series resonances of the parallel paths are rejected. In this manner, an extra null in the circuit's stop-band may be achieved using the same number of shunt elements necessary to achieve impedance matching at the fundamental frequency.

A mode-locked laser with intracavity frequency conversion is disclosed. In one embodiment the conversion frequency is improved by reducing the temporal, spatial, or polarization overlap between pulses at the fundamental frequency and pulses at a frequency-shifted frequency.

A method is disclosed for determining fundamental-frequency repeatable runout (1FRRO) coefficients in a disk drive. The disk drive includes a transducer head, a rotating magnetic disk having a plurality of concentric data tracks defined by embedded servo wedges that provide position information, and an actuator coupled to the head. In the method, the head is caused to move in a substantially constant velocity motion across a selected portion of the tracks of the rotating magnetic disk in response to a control signal. The position information is read from the embedded servo wedges as the head moves across of the selected portion of the tracks. The 1FRRO coefficients are determined based on the position information read as the head moved in a substantially constant velocity motion across the selected portion of the tracks.

A device for converting alternating voltage to direct voltage and, conversely, direct voltage into alternating voltage. A series connection between the poles of a direct voltage side has at least four units each having a semiconductor element of turn-off type and a first diode connected in anti-parallel therewith. A first midpoint of the series connection is connected to an alternating voltage phase line and forms a phase output. Second midpoints of the series connection are connected to a midpoint of the direct voltage side through such units. An apparatus is adapted to control the semiconductor elements with a pulse width modulation frequency of at least one order of magnitude higher than the fundamental frequency of the alternating voltage of the phase line and the rest of the semiconductor elements with a frequency substantially lower and within or close to the frequency range of one or a couple of times of the fundamental frequency.

An active gain region sandwiched between a 100% reflective bottom Bragg mirror and an intermediate partially reflecting Bragg mirror is formed on a lower surface of a supporting substrate, to thereby provide the first (“active”) resonator cavity of a high power coupled cavity surface emitting laser device. The reflectivity of the intermediate mirror is kept low enough so that laser oscillation within the active gain region will not occur. The substrate is entirely outside the active cavity but is contained within a second (“passive”) resonator cavity defined by the intermediate mirror and a partially reflecting output mirror, where it is subjected to only a fraction of the light intensity that is circulating in the gain region. In one embodiment, non-linear optical material inside each passive cavity of an array converts an IR fundamental wavelength of each laser device to a corresponding visible harmonic wavelength, and the external output cavity mirror comprises a Volume Bragg grating (VBG) or other similar optical component that is substantially reflective at the fundamental frequency and substantially transmissive at the harmonic frequency. The VBG used in an array of such devices may be either flat, which simplifies registration and alignment during manufacture, or may be configured to narrow the IR spectrum fed back into the active resonant cavity and to shape the spatial mode distribution inside the cavity, thereby reducing the size of the mode and compensating for any deformations in the semiconductor array.

A single-phase hybrid multilevel inverter is described that combines a 3-level leg and a 2-level leg to reduce the number of overall switching devices for a 5-level inverter. The 2-level inverter leg switches at a fundamental frequency and the 3-level flying capacitor leg uses PWM modulation to switch resulting in a low THD output voltage spectrum. The control method developed for the single-phase inverter is used to build a three-phase inverter comprised of three single-phase hybrid inverters in order to achieve a line-to-neutral voltage having five levels and a line-to-line voltage having nine levels.

The invention concerns a high frequency surgery apparatus for cutting and / or coagulating biological tissue and methods of operating same. The high frequency surgery apparatus includes at least one high frequency generator which in operation forms a high frequency circuit with the tissue to be treated, with the production of an arc, and at least one measuring and calculating device which is connected for signal transmission to the high frequency circuit and which is adapted in operation to ascertain both a DC voltage in the high frequency circuit and also the amplitudes of at least one even and at least one odd harmonic of a fundamental frequency of the high frequency generator and to form a first tissue parameter representative of the kind of tissue to be treated from the relationship of the sum of the amplitudes of the even and the odd harmonics to the DC voltage and to output a tissue signal dependent on the first tissue parameter for subsequent processing.

An inductive power transfer system (10) for roadways includes at least one drive unit arrangement (50) coupled to at least one drive coil arrangement (40) disposed along a roadway (20) for generating a magnetic field extending upwardly from the roadway (20), and at least one vehicle (30) including a corresponding pickup coil arrangement (60) coupled to a power conditioning circuit arrangement (80, 200) for receiving the extending magnetic field for providing power to operate the at least one vehicle (30). The at least one drive unit arrangement (50) is operable to excite, for example at resonance, the at least one drive coil arrangement (40) at a fundamental frequency (f0) of at least 30 kHz, preferably at least 50 kHz, more preferably at least 100 kHz, and most preferably at least 140 kHz. The at least one drive coil arrangement (40) is implemented to be substantially devoid of ferromagnetic components for providing a path for the extending magnetic field. Optionally, the at least one drive unit arrangement (50) is operable to employ a balanced class-E amplifier arrangement for exciting the at least one drive coil arrangement (40) at the fundamental frequency (f0). Optionally, the at least one drive unit arrangement (50) is operable to employ one or more Silicon Carbide semiconductor devices for switching the currents provided to the corresponding at least one drive coil arrangement (40). Optionally, there is further included a passive and / or active suppression arrangement (100, 110, 120, 130, 140) for suppressing harmonic magnetic field components generated by the system (10) at multiples of the fundamental frequency (f0) when in operation.

Circuitry and techniques designed to allow stable and continuous delivery of alternating power to a plasma with switch-mode power supply (16) include a variety of embodiments. Parallel, series, and other circuit elements connected across switching element (7) are tuned so that energy at other than the fundamental frequency is absorbed and dissipated. This energy may be only at the second harmonic or it may be across broad frequency ranges through selecting high impedance at the fundamental frequency and relatively low impedance at other frequencies. In overcoming instabilities, oscillations, and even changing class of operation of the switch-mode power supply, the stabilizing element absorbs the energy to avoid allowing it to affect switch (7) of power supply (16).

An implantable medical device evaluates ventricular synchrony by determining a phase angle between at least two sensor signals that reflect mechanical contraction of the ventricles. In exemplary embodiments, two intracardiac impedance signals associated with the right and left ventricles, respectively, with two points within either of the left and right ventricles, or with both the left and right ventricles relative to a reference point, are processed. In such embodiments, fundamental frequency phases of each of the impedance signals may be compared to determine the phase angle between the signals. In some embodiments, the signals are used to dynamically adjust one or more timing intervals, such as a V-V timing interval, for delivery of cardiac resynchronization therapy (CRT) pacing. In such embodiments, the one or more timing intervals are periodically adjusted to reduce or possibly eliminate ventricular dysynchrony as indicated by the phase angle between the sensor signals.

The invention relates to a cable-overhead joint line failure travelling wave range count method, particularly performing the effective fusion based on the failure range count method of the fundamental frequency and the travelling wave aiming at the particularity and the complexity of the cable joint line, belonging to the technical field of the power system relay protection. The invention judges the failure generating places firstly based on the cable-overhead junction derivated through the electric quantity at the two ends of the system attached with the negative sequence net after the failure, then performs the correct range count by the range count method of the single end; on the basis of considering the line zero modulus component couple, through comparing the performance of the current travelling wave line zero modulus component, the performance of each reflected wave is judged, to find out the fault point reflected wave, and then perform the correct range count.

A loudspeaker system with a transducer and an enclosure with at least one resonant chamber, including a resonant-chamber resonance frequency, at which a displacement characteristic of a vibratile diaphragm of the transducer has a minimum. The loudspeaker system further includes a multi-mode signal processor with a set of signal processes wherein in one example, a variable gain, frequency selective dynamic filter reduces the gain in a high displacement frequency range upon an output in the frequency range exceeding an overload amplitude threshold. The gain reduction is compensated for by complimentary frequency generating signal processes, including at least one of a harmonics generator and a transpositional gain controller, with the signal processor adapted to match the resonant chamber enclosure by substantially maintaining or increasing acoustic output at the resonant chamber resonance and generating harmonics associated with fundamental frequencies in the gain reduced frequency range to maintain a perception of tonal quality and physical bass impact, increasing low frequency capability while minimizing audible overload distortion.

The invention discloses a conversion method for sound of a speaker. The method comprises a training stage and a conversion stage, wherein the training stage comprises the steps of respectively extracting a fundamental frequency characteristic, a speaker characteristic and a content characteristic from training voice signals of a source speaker and a target speaker, constructing a fundamental frequency conversion function according to the fundamental frequency characteristic, and constructing a speaker conversion function according to the speaker characteristic. The conversion stage comprises the steps of extracting a fundamental frequency characteristic and a spectrum characteristic from a voice signal to be converted of the source speaker, using the fundamental frequency conversion function and the speaker conversion function obtained in the training stage to convert the fundamental frequency characteristic and the speaker characteristic extracted from the voice signal to be converted, obtaining the converted fundamental frequency characteristic and the speaker characteristic, and synthesizing voices of the target speaker according to the obtained converted fundamental frequency characteristic, the speaker characteristic and the content characteristic in the voice signal to be converted. The method is easy to realize, and the converted sound quality and similarity are higher.

The invention provides techniques for reducing or altering the magnetic noise of an AC rotary electric machine. A magnetic noise reducing harmonic current of order n, whose frequency is n times the frequency of the fundamental frequency component of a polyphase AC current fed to an armature of a polyphase AC rotary electric machine, is superimposed on the polyphase AC current, thereby reducing or altering a harmonic component having a frequency (n−1) times the frequency of the fundamental frequency component and occurring due to a radial magnetic excitation force acting radially on an iron core of the AC rotary electric machine. Magnetic noise is caused by a vibration whose energy is the sum of the circumferential and radial vibrations of the iron core occurring due to the magnetomotive force of the rotor, and altering the radial vibration is particularly effective in altering the magnetic noise; as the harmonic component of the radially acting magnetic excitation force, occurring due to harmonic components having frequencies 3, 5, 7, and 13 times the fundamental frequency, has a frequency 6 or 12 times the fundamental frequency, the magnetomotive force of the rotor can be effectively reduced or altered when a current having a frequency 7 or 13 times the fundamental frequency is superimposed on the stator current.

A nano electromechanical integrated circuit filter and method of making. The filter comprises a silicon substrate; a sacrificial layer; a device layer including at least one resonator, wherein the resonator includes sub-micron excitable elements and wherein the at least one resonator possess a fundamental mode frequency as well as a collective mode frequency and wherein the collective mode frequency of the at least one resonator is determined by the fundamental frequency of the sub-micron elements.

A Doppler radar signal processing system and method and a Doppler radar employing the system or the method. In one embodiment, the system includes: (1) an input configured to receive at least one radar output signal representing a reflected Doppler radar signal, (2) signal processing circuitry coupled to the input and configured to produce an arc-length cardiopulmonary signal from the at least one radar output signal and employ a respiration fundamental frequency estimate to extract a heart rate signal from the arc-length cardiopulmonary signal and (3) an output coupled to the signal processing circuitry and configured to provide the heart rate signal.

Several embodiments of medical ultrasound handpieces are described each including a medical ultrasound transducer assembly. An embodiment of a medical ultrasound system is described, wherein the medical ultrasound system includes a medical ultrasound handpiece having a medical ultrasound transducer assembly and includes an ultrasonically-vibratable medical-treatment instrument which is attachable to a distal end of the transducer assembly. An embodiment of a medical ultrasound system is described, wherein the medical ultrasound system has a handpiece including a medical ultrasound transducer assembly and including a housing or housing component surrounding the transducer assembly. A method for tuning a medical ultrasound handpiece includes machining at least a distal non-threaded portion of an instrument-attachment stud of the transducer assembly to match a measured fundamental frequency to a desired fundamental frequency to within a predetermined limit. A method for making a medical ultrasound transducer assembly determines acceptable gains for gain stages of the transducer assembly.

A system and method for reducing leakage current in an electrosurgical generator are disclosed. The system includes an electrosurgical generator configured to provide high frequency electrosurgical energy at a fundamental frequency. The generator includes one or more circuit boards having a board ground. The generator further includes a inductor-capacitor filter connected in series with the board ground and an earth ground. The inductor capacitor filter includes a capacitor connected in parallel with an inductor and is tuned to be at an operational frequency which is resonant at or near the fundamental frequency.

Circuits and methods of LED dimming are disclosed. Frequency modulation using controlled modulation depth generates deterministic sidebands of both the fundamental frequency and its harmonics. Various filters including low-pass, band-pass, high-pass and combinations of those are used to selectively filter the deterministic frequency components generated by the frequency modulation to achieve LED dimming.