524 results about "Sinusoidal waveform" patented technology

A signal processor generates basis functions and identifies at least one basis function component of a sensor signal in order to calculate a physiological measurement. The signal processor is advantageously applied to pulse oximetry so as to directly calculate oxygen saturation and so as to calculate a robust oxygen saturation measurement. In particular, a signal component transform may be calculated within a window around a derived pulse rate estimate. A signal component transform may also utilize sinusoidal basis functions, and an optimization of a signal component transform may occur at a particular frequency or a set of frequencies. A sinusoidal waveform or waveforms at that frequency or set of frequencies is generated to select associated red and infrared components of the sensor signal, and an oxygen saturation is calculated from a magnitude ratio of these components.

A gastric reduction apparatus that facilitates the creation of a transoral linear passageway through the stomach includes an elongated body including a proximal end and a distal end. The elongated body is generally sinusoidal shaped with at least one tissue engaging surface oriented such that a needle will pass therethrough. The elongated body also includes at least one needle passing channel respectively formed adjacent the at least one tissue engaging surface. The at least one needle passing channel generally passes through the center of the sinusoidal waveforms defined by the at least one tissue engaging surface such that a needle will pass entirely through stomach tissue contacting the tissue engaging surface of the elongated body. The elongated body further includes a suture passing channel.

Distortion modeling produces distortion models for use by a distortion synthesizer to synthesize the harmonic distortion effects of audio distortion devices. A sinusoidal waveform is distorted by an audio distortion device and analyzed using a Fourier transform to produce a distortion model comprising harmonic amplitude and phase parameters. A phase correction process compensates for phase shifts induced by the audio distortion device. The distortion synthesizer uses a distortion function that distorts a digital audio signal according to the distortion model. The distortion model can be modified to alter the distortion effect and can be stored in a data-storage device for later retrieval. A frequency bandsplitter and signal mixer allow the distortion effect to be applied only to the low frequency content of the digital audio signal, thus providing spectral headroom to suppress the production of aliasing noise. Aliasing-noise suppression is provided for a full-bandwidth signal by up-converting the sampling rate of the signal before applying the distortion function and down-converting the sampling rate afterwards. A process is provided to remove the direct-current component that may be induced into the signal by the distortion function.

A high frequency electrosurgical power generator configured to produce electrical power at a frequency of about 1 to about 14 MHz and preferably having an essentially sinusoidal waveform with a voltage level up to 1,000 Vrms, and a current level up to 5 Amps. The output of the high frequency electrosurgical power generator is connected to an electrosurgical tool configured to receive the voltage and current produced by the electrosurgical power generator and deliver the voltage and current to an electrosurgical site. The output of the electrosurgical generator preferably is an essentially sinusoid waveform with a frequency between about 3 MHz and about 8 MHz, up to about 700 volts rms, up to about 2 amps, with a total power of up to 1,000 watts.

An electrosurgical generator is disclosed, which includes an RF output stage connected to a DC power supply and first and second connections. The first connection includes a first switching component and a first parallel inductor-capacitor resonant circuit. The second connection includes a second switching components and a second parallel inductor-capacitor resonant circuit. The first and second switching components are configured to open and close at a predetermined frequency based on a phase-correlated dual drive signal emitted by a driver and are in a 180 degree out-of-phase relationship. The first parallel inductor-capacitor resonant circuit is further configured to produce a first half-sinusoidal waveform and the second parallel inductor-capacitor resonant circuit is configured to produce a second half-sin half-sinusoidal waveform. The RF output stage further includes a transformer having a primary winding and a secondary winding and a series inductor-capacitor resonant circuit, which are configured to generate a sinusoidal waveform.

According to one aspect, embodiments of the invention provide power converter circuitry including an input including a plurality of input lines each configured to be coupled to a phase of a multiphase AC power source having a sinusoidal waveform, a plurality of DC buses including a first positive DC bus having a first nominal DC voltage, a second positive DC bus having a second nominal DC voltage, a first negative DC bus having a third nominal DC voltage and a second negative DC bus having a fourth nominal DC voltage; a first power converter coupled to the input and configured to supply power from the multiphase AC power source to the plurality of DC buses during a first positive region of the sinusoidal waveform and a first negative region of the sinusoidal waveform; and a second power converter coupled to the input and configured to supply power from the multiphase AC power source to at least some of the plurality of DC buses during a second positive region of the sinusoidal waveform and a second negative region of the sinusoidal waveform.

The invention relates to a bidirectionally isolating type series resonance DC/DC converter (100) which comprises voltage-stabilizing capacitors (22, 32), high-frequency converters (20, 50), series resonance circuits (30, 40), a high-frequency transformer (28) and an energy storage unit (60), wherein the voltage-stabilizing capacitors (22, 32) are used for enhancing the stability of a DC voltage; the high-frequency converters (20, 50) have the same structure and comprise four switching elements inversely connected in parallel with a rapid diode and can be used for inversion and rectification; the series resonance circuits are used for converting three kinds of discrete levels output by corresponding high-frequency converters into sinusoidal waveforms and can be used for softly switching the switching elements of the corresponding high-frequency converters, at the same time, only one series resonance circuit (30 or 40) acts; and the high-frequency transformer (28) can be used for isolation and transformation. The transformer (100) can be used for greatly converting the DC voltage, has high efficiency, and can be applied to an electric vehicle power supply, standby power supplies of large-scale equipment, and the like.

Fast kV-switching is a dual energy acquisition technique in computed tomography (CT) in which alternating views correspond to the low and high tube voltages. Its high temporal resolution and its suitability to a variety of source trajectories make it an attractive option for dual energy data acquisition. Its disadvantages include a one-view misregistration between the data for high and low voltages, the potentially poor spectrum separation due to the more-like a sine wave rather than the desired square wave in fast kV-switching, and the higher noise in the low voltage data because of the technical difficulty in swinging the tube current to counter the loss of x-ray production efficiency and loss of penetration at lower tube voltages. Despite the disadvantages, symmetric view matching according to the current invention substantially improves streaks and other artifacts due to the view misregistration, sufficient spectrum separation even in a sinusoidal waveform swinging between 80 kV and 135 kV, and contrast-to-noise for the simulated imaging task maximized at monochromatic energy of 75 keV.

A point-to-point communications system (20) for transmitting messages from any location (A) within a power distribution system or network (10) to any other location (B) within the network. A transceiver (12) at the one location includes a transmitter (X) that impresses a waveform (W_R) on a waveform (W_G) propagated by the network to supply power throughout the network. The transmitter is a resonant transmitter that includes a reactive load (13) which is selectively connected to and disconnected from the power distribution network. A controller (16) controls operation of the transmitter to connect and disconnect the reactive load from the network so to impress on the propagated waveform a dampened sinusoidal waveform whose characteristics represent information conveyed over the power distribution system. A receiver (Yn) at the other location receives and demodulates the dampened sinusoidal waveform to extract therefrom the information being conveyed by it.

A method and system for detecting the peak of respective half-cycles of a sinusoidal waveform. The sinusoidal waveform is rectified and only sample points above a first threshold are analyzed. The peaks of each half-cycle are only accepted if they are above a second, greater threshold. Peaks below the second threshold are not accepted. The peaks themselves are detected by starting a counter at the first sample in the rectified waveform which is above the first threshold value. Once the rectified waveform descends below the first threshold, the counter is stopped and the maximum value of the previous k samples is the peak value, where k is the counter value for the successive samples above the first threshold. The peak value so determined is rejected if it is less than the second threshold value. On the other hand, when the peak value is above the second threshold, it is averaged with the last valid peak value (above the second threshold). Thus, the V/Hz value remains the same until a new, valid peak is determined. A preferred embodiment implements such a digital peak detector in a digital relay system for detecting overexcitation of a power system.

The invention relates to a dimming control method for lamps, in particular to a digital dimming control method and a digital dimming control system for two-wire fluorescent lamps. In the method, the lamps are controlled by power lines. The digital dimming control method for the two-wire fluorescent lamps comprises a system consisting of a dimming controller 1 and a dimming ballast 2, and a digital protocol. The digital protocol perform addressing on the controlled next-stage lamps through a control instruction and/or a data set to combine a group of control signals and/or address codes through different waveforms, and the control signals and/or the address codes are transmitted to the ballast directly through a power line of the ballast, so that the turn-on, turn-off and/or luminance of each next-stage lamp are controlled. By the method of the invention, after a group of waveforms are transmitted, a power supply signal restores to the original integral sinusoidal waveform, so additional electromagnetic interference is not generated; and digital quantity is used rather than analog quantity in the process of transmission, so the fluctuation of voltage does not influence the dimming performance.

A massage machine using a small size and high torque brushless DC motor includes a driving unit moved up and down along guide rails of a chair and a first motor for moving the driving unit up and down. A pair of treatment head bases are driven reciprocally in opposite directions to each other; and a second motor reciprocally drives the treatment head bases in opposite directions to each other. Treatment heads are respectively supported by the treatment head bases; and a third motor drives the treatment heads in a plane substantially perpendicular to a backrest. A control circuit drives the respective motors respectively independently of one another. Each motor is a brushless motor. A control circuit corrects, corresponding to a load imposed on the brushless DC motor, a waveform of a drive signal applied to a winding of the brushless DC motor so as to allow a current flowing through the winding of the brushless DC motor to have a substantially sinusoidal waveform making it possible to reduce discomfort due to motor noise, and to accurately control the motor rotation speed.

The invention discloses a method for rolling a high-strength metal composite plate. The method is characterized in that a metal substrate and a cladding plate are selected, it is required that the deformation resistance of the metal substrate is larger than that of the cladding plate, the composite faces of the substrate and the cladding plate are cleaned, the substrate with the large deformation resistance is machined to obtain the substrate with a corrugated face on the composite face, the section of each corrugation is in an arc shape or a sinusoidal wave shape or an oval shape, and the height s of the corrugations, the width t of the corrugations and the thickness h0 of a metal layer with the large deformation resistance satisfy the conditions that s/h0 ranges from 0.1 to 0.8, 2s/t is equal to tan alpha, and alpha ranges from 10 degrees to 40 degrees; the substrate and the cladding plate are stacked and pressed in sequence, and a double-layer composite plate blank is obtained; and a composite plate strip is obtained after rolling is conducted according to the warm-rolling process or the hot-rolling process. By the adoption of the method, the problem of difference of metal plastic deformation caused by different degrees of deformation resistance of dissimilar metals is solved, and the curved surface of the substrate makes compensation for the difference, so that the rolled cladding layer and the rolled substrate layer are matched in length without buckling, and meanwhile the binding force between the substrate and the cladding plate is increased through traction on the cladding plate of the corrugations of the substrate.

A frequency multiplier and amplification circuit are disclosed. One embodiment of the present invention comprises: a multiplier operably coupled to multiply a first sinusoidal waveform having a first frequency with a second sinusoidal waveform having a second frequency to produce a third sinusoidal waveform, having a frequency representative of a difference between the first frequency and the second frequency, and a fourth sinusoidal waveform having a frequency representative of a sum of the first and second frequencies; and a frequency-tuned load operably coupled to substantially attenuate the third sinusoidal waveform and to substantially pass the fourth sinusoidal waveform as an output of the frequency-tuned multiplier circuit. The frequency-tuned multiplier circuit can be a single-ended multiplier circuit or a differential multiplier circuit with corresponding single-ended or differential first and second sinusoidal waveforms.

A method for generating a compound signal wave with one or more substantially sinusoidal waveform(s) containing an encoded digital information combined with a variable phase changing waveform(s) producing a compound notched sinusoid waveform that includes at least a sine wave that is amplitude-time modulated and at least one phase modulated wave(s). The encoded digital information can be 1 to n bits per cycle limited only by hardware clock speeds. The phase shifting modulation can be implemented as data or control function(s) with real-time adjustment (within a cycle) of data control, data management, and data security. The compound signal wave is transmitted through existing communication channels or a program controlled modulator with 0 to n degrees (levels) of phase modulation. On the receive end of the communications channel the received signal containing the amplitude-time modulated wave and the phase modulated wave(s) are interrupted by either a decoding of amplitude-time modulation distortions by existing hardware or a program controlled demodulator with 1 to n degrees (levels) of phase modulation. Data values can be directly encoded or contained in a look up table or list. Presence or absence of change to a wave's sinusoidal amplitude within a phase indicates a data value. These data values can be changed within a data cycle or packet. Reduced modulation distortion is exhibited by amplitude-time modulation techniques when compared to classical amplitude modulation techniques. This reduced distortion in a communications signal results in increased effective transmission lengths, reduced error rates, higher data rates, and improved data security (real-time control of values, phase, and control exacerbate snooping attempts).

The invention discloses an electric bicycle control method based on a permanent magnet brushless direct current motor. According to the method, subdivided rotor position information is used for directly starting the motor, and the switching procedure from square wave starting to sine wave starting in a traditional control method is omitted. The electric bicycle control method relates to a rotor section calculation module, a speed calculation module, an angle subdivision module, a phasing adjustment module, a speed control module, a current-limiting control module, a waveform modulation module, a three-phase inverter and a motor starting module. By the adoption of the method, control efficiency and control performance are improved, and currents passing through a motor winding are in a sine wave mode when the motor operates; compared with a traditional square wave control method, torque pulsation is small, motor running noise is low, and the service life of the motor can be prolonged; compared with a traditional space vector control method, the algorithm is simple, implementation is easy, the requirement for a microprocessor is low, and high cost performance is achieved.

A method for generating a substantially sinusoidal waveform containing encoded digital data having one of a first value and a second value at selected phase angles θ_n comprises generating the waveform having an amplitude Y defined by a first function at phase angles lying outside of regions having a range Δθ beginning at each phase angle θ_n, said first function being Y=sin θ; generating the waveform having an amplitude Y defined by the first function at phase angles lying inside the regions having a range of Δθ beginning at each phase angle θ_n where data of the first value is to be encoded; and generating the waveform having an amplitude Y defined by a second function at phase angles lying inside the regions having a range of Δθ associated with each phase angle θ_n where data of the second value is to be encoded, the second function being different from Y=sin θ.

In the transformer, line side windings connected in star type continuous form is adopted in inner side. Structure of outer side is three groups divided, N groups phase shifted cake typed line side windings. The invented transformer solves issues of harmonic polluting on power grid and harmonic wastage, possessing advantages: reliable operation, simple maintenance, small harmonic current at power grid side, low noise, low heat generated, high power factor. When being applied to high voltage frequency control, the invention solves issues: heating of motor, torque ripple, influence of dv/dr and common mode voltage on insulation of motor. The invention can reaches ideal effect of harmonic elimination even if out of balanced currents occurred, providing advantages of approximate to sinusoidal waveform output, high conversion efficiency etc.

A method for generating a substantially sinusoidal waveform containing encoded digital data having one of a first value and a second value at selected phase angles θ_n comprises generating the waveform having an amplitude Y defined by a first function at phase angles lying outside of regions having a range Δθ beginning at each phase angle θ_n, said first function being Y=sin θ; generating the waveform having an amplitude Y defined by the first function at phase angles lying inside the regions having a range of Δθ beginning at each phase angle θ_n where data of the first value is to be encoded; and generating the waveform having an amplitude Y defined by a second function at phase angles lying inside the regions having a range of Δθ associated with each phase angle θ_n where data of the second value is to be encoded, the second function being different from Y=sin θ.

In a laser printer, methods and apparatus include commutating a brushless dc motor having three windings. A controller receives discrete motor position signals, such as from hall-effect or FG sensors, and extrapolates motor position between the signals. It commutates the motor based on the extrapolated motor position and updates motor position whenever an actual discrete signal is received. Drive signals from the controller to the motor are such that a current flowing in any of the three windings follows a generally sinusoidal waveform. High and low switches are provided per each winding of the three windings and are cumulatively switched according to an extrapolated motor position based multiplier applied to a pulse width modulation duty cycle. In this regard, lookup tables, counters, registers and the like are provided. An engine card of the printer includes an ASIC with a power driver for use with generally off-the-shelf brushless dc motors.