2549 results about "Sine wave" patented technology

A near field RF communicator has: an antenna operable to generate an RF signal to enable inductive coupling via the magnetic field of the RF signal between the antenna and another near field RF communicator or RF transponder in near field range; and a signal generator operable to generate a multi-level digital sine wave drive signal to drive the antenna to generate the RF signal, wherein the signal generator comprises a selector operable to select one or more digital sequences to provide one or more digital signals from which the digital sine wave drive signal is generated.

A rotary sensor that outputs two analog signals, such as one sine wave and one cosine wave and has multiple periods within one period of the electrical angle of a motor is employed. The motor is energized at each position for a specified length of time upon its startup by using multiple electrical angles corresponding to the multiple candidate absolute angles obtained from the rotary sensor signal as the initial position of the motor, and the electrical angle at which the motor acceleration becomes maximum is determined as the absolute angle. While the motor drive is in operation, on the other hand, the phase difference Δθ between the phase of the motor at the counter electromotive voltage and the control phase is directly computed from the parameters of the motor, sensed current, voltage command and angle speed so as to correct the shifted position. A high-efficiency motor drive unit with improved maintainability of rotary sensor and improved accuracy of sensing the magnet pole position of a permanent magnet synchronous motor that accelerates and decelerates very quickly in a wide range of speed is realized.

An implantable medical lead for spinal cord, peripheral nerve or deep brain stimulation comprises a lead body which includes a deformable sigma segment preferably in the shape of a sine wave and a lead paddle coupled to the lead body at the distal end thereof. The lead body at its proximal end may be coupled to an implantable pulse generator, additional, intermediate wiring or other stimulation device. The lead paddle may comprise a plurality of electrode contacts for providing electrical stimulation to targeted human tissue. The lead body, which defines the sigma segment, in a plane, couples the lead paddle and pulse generator. The sigma segment provides flexing and bending of the wire when a patient shifts or moves, and especially provides longitudinal extension between the pulse generator and lead paddle.

In a method and apparatus for controlling power factor correction in mixed operation modes, a frequency of the input voltage is obtained by detecting the zero crossing points of the input voltage. A peak of the input voltage is obtained by detecting input voltage with 90 degree phase. Thus, the present invention predicts the input voltage by its frequency and peak and the characteristic of the sine wave. A digital signal processor computes the duty and frequency of a boost switch, switching the operation mode of the boost converter among continuous mode, critical mode and discontinuous mode according to input voltage or the load. According to another aspect, the operation is switched to critical mode from the average current mode when a zero current is detected before the charging and recharging cycle of the boost switch is finished.

In one embodiment, the present invention includes a test signal generator capable of producing an impedance test signal comprising of a sine wave having a known frequency. The test signal generator may include a crystal oscillator, a counter, and a lookup table. The lookup table output is applied to a digital to analog converter and is then low pass filtered using a conventional analog filter to produce a sine wave of a known frequency and voltage amplitude. The test signal flows through the electrode and combines with an electrophysiological signal to form a combined signal. A signal processor is used to isolate the combined signal into the test signal component and the electrophysiological component. The signal processor digitally low pass filters the combined signal and the output of the low pass filter is the electrophysiological signal. The signal processor then digitally bandpass filters the combined signal using a filter with a center frequency which is the same as the test frequency. The output of this filter is then used to calculate the electrode impedance.

The invention discloses a square wave-sine wave signal transformation method comprising the steps as follows: a square wave signal generates N square wave control signals with the same period; the N square wave control signals arrayed in sequence respectively generate N square wave secondary signals; the amplitude sum of the N square wave secondary signals is a; the amplitude of the square wave signal n is a right type; the N square wave secondary signals are processed through superposition to obtain a false sine wave signal; and the false sine wave signal is processed through filtration to obtain a sine wave signal. A square wave-sine wave signal transformation circuit is also disclosed, and the superposition of the N square wave secondary signals in the method is realized by controlling the superposition of current so as to obtain the sine wave signal. The square wave-sine wave signal transformation method and the square wave-sine wave signal transformation circuit avoid adopting a higher order high-frequency filter directly, greatly save the area and the power consumption of a chip, and reduce the design complexity.

Embodiments of the present invention provide an apparatus and method of generating electrical stimulation waveforms using Direct Digital Synthesis (DDS). The waveform generation substantially reduces intensive processor calculations and commands required for the generation of waveforms via Pulse Width Modulation (PWM). DDS technology is integrated into single-integrated circuit components, capable of generating waveforms based on singular digital word commands. The use of DDS integrated circuits allows for rapid changes in frequencies, automatically sweeps frequencies between user defined limits, and are capable of a wide range of frequencies. Further, utilization of DDS in waveform generation allows for software updatable functionality. Additionally, because DDS technology outputs a smooth sine wave, the need for extensive filtering is drastically reduced. Further, DDS technology can be utilized in an amplitude modulation stage beyond the DDS waveform generator, further reducing the burden on processor systems.

A low-cost sine-wave drive for a 3-phase permanent magnet synchronous AC machines (PMSM) in open-loop control is based on the measurements of two linear Hall sensors. The two Hall sensors are excited by a magnetic ring with the same pole number as the PMSM rotor magnet and sinusoidal flux distributions. The output signals of the Hall sensors are unified through a two-phase-type phase-lock-loop in order to reduce the impact of the sensor mounting non-uniformity during mass production. The peak torque and speed of motor is simply controlled by adjusting the amplitude of pulse-width-modulation carrier. Smooth torque control is achieved due to sinusoidal 3-phase currents. Such a simple sine-wave drive can be achieved with or without the assistance of a micro-controller unit (MCU). No current sensor is required for the motor phase current detection. This motor can be used in industrial applications where there is no strict requirement on torque response and constant speed control of PMSM machines.

In an operation range of an actuator subjected to quick acceleration and deceleration, a motor drive apparatus, an electric actuator and an electric power steering apparatus capable of continuous torque control up to the high drive speed and high torque area. A controller comprises a voltage saturation detecting means for detecting the voltage saturation of the output voltage of an inverter circuit, based on the battery voltage, and a waveform controller that converts the drive waveform of the inverter circuit into the waveform created by superimposing harmonics of high odd-numbered order on a sinusoidal wave as a fundamental wave of the modulated wave modulated by a PWN carrier wave; and continuously changes the ratio of superimposing the high-order harmonics in response to the voltage saturation detected by a voltage saturation detecting means. This arrangement allows the controller to continuously change the drive waveform of the inverter circuit.

A lower substrate including a first electrode and an upper substrate including a second electrode are opposed to each other. Partitioned spaces between the two substrates correspond to pixels, each including negatively charged black particles and positively charged white particles. In the lower substrate, a piezoelectric material is sandwiched between a third electrode and the first electrode, thereby forming a vibration-generating portion. In a display operation, a signal voltage corresponding to an image signal is applied between the first and second electrodes, and thus, the black particles and the white particles travel between the electrodes and adhere to the respective electrode surfaces to perform the display operation. Before rewriting the display, a sine wave voltage is applied between the first electrode and the third electrode to cause the vibration-generating portion to generate vibration. Aggregated particles are dissociated, and particles adhering to the electrode are detached, by the vibration.

Apparatus for conditioning power generated by an energy source includes an inverter for converting a DC input voltage from the energy source to a square wave AC output voltage, and a converter for converting the AC output voltage from the inverter to a sine wave AC output voltage.

The present invention relates to an electronic ballast that energizes fluorescent lamps connected in a parallel configuration. The ballast employs a power factor correcting boost converter that can be used over a wide range of AC line voltages to provide regulated power to a self-oscillating sine wave inverter that drives the fluorescent lighting load at high frequencies. The inverter employs special networks that limit a certain type of shoot-through current, and thus improve the efficiency of the unit. Also included is a restart circuit that limits power losses during the zero lamp condition, by periodically interrupting the inverter operation when the zero lamp state is detected. To improve operation of the power factor correcting circuitry over the wide range of AC line voltages, a DC offset is added to the sampled AC voltage at the higher AC line voltages by Zener diode based coupling circuit.

A bias generation method or apparatus defined by any one or any practical combination of numerous features that contribute to low noise and/or high efficiency biasing, including: having a charge pump control clock output with a waveform having limited harmonic content or distortion compared to a sine wave; having a ring oscillator to generating a charge pump clock that includes inverters current limited by cascode devices and achieves substantially rail-to-rail output amplitude; having a differential ring oscillator with optional startup and/or phase locking features to produce two phase outputs suitably matched and in adequate phase opposition; having a ring oscillator of less than five stages generating a charge pump clock; capacitively coupling the clock output(s) to some or all of the charge transfer capacitor switches; biasing an FET, which is capacitively coupled to a drive signal, to a bias voltage via an “active bias resistor” circuit that conducts between output terminals only during portions of a waveform appearing between the terminals, and/or wherein the bias voltage is generated by switching a small capacitance at cycles of said waveform. A charge pump for the bias generation may include a regulating feed back loop including an OTA that is also suitable for other uses, the OTA having a ratio-control input that controls a current mirror ratio in a differential amplifier over a continuous range, and optionally has differential outputs including an inverting output produced by a second differential amplifier that optionally includes a variable ratio current mirror controlled by the same ratio-control input. The ratio-control input may therefore control a common mode voltage of the differential outputs of the OTA. A control loop around the OTA may be configured to control the ratio of one or more variable ratio current mirrors, which may particularly control the output common mode voltage, and may control it such that the inverting output level tracks the non-inverting output level to cause the amplifier to function as a high-gain integrator.

A method for treating a soft tissue wound is provided and includes the steps of providing a signal generator in electrical communication with first and second electrodes, disposing the first and second electrodes on a skin surface on opposing sides of the soft tissue wound and applying an electric field in the soft tissue wound by generating a voltage at a frequency within a range of 20 to 100 kHz and having a symmetrical waveform with an amplitude within a range of 0.1 to 20 volts peak to peak through said first and second electrodes. In accordance with a first preferred embodiment the signal generator is an AC generator generating a sine wave voltage and in accordance with second and third preferred embodiments, the signal generator is a bipolar DC generator, all generating a symmetrical waveform at a frequency of 60 kHz, with an amplitude of about 5 volts peak to peak.

The invention discloses a charging-discharging system for a V2G bilateral power conversion electric automobile and a control method thereof, which belong to the technical field of intelligent power grids. In the charging-discharging system, a single-phase or three-phase voltage PWM (Pulse Width Modulation) converter (VSC) is taken as a first-grade power conversion circuit, so that energy conversion between an alternating-current power grid and a first direct-current bus is realized; and a symmetric half-bridge LLC (Logical Link Control) resonant bilateral direct current-direct current (DC/DC) converter is taken as a second-grade power conversion circuit, so that energy conversion between a direct-current bus and a power battery pack is realized. The charging-discharging system has the beneficial effects that: the current of the converter power grid side of the first-grade power conversion circuit is approximate to sine wave, so that the harmonic content is small; and the converting efficiency, dynamic performance and power density of the second-grade power conversion circuit are increased, the volume and weight of a charging-discharging device of the electric automobile are reduced, and the safety, reliability and economic efficiency of the system are improved effectively.

A combined AC/DC monitoring system simultaneously monitors an AC power supply and a DC power supply in a mobile unit. The monitoring system is electrically isolated from an AC input source through an AC isolation transformer. A microcontroller digitally provides various computed variables from various digitized input signals. The monitoring system simultaneously displays a plurality of the computed variables while the system monitors for various user-selected high/low conditions of the computed variables. The system monitors AC power surges and can alternately displays a high voltage level for a predetermined time and a low voltage level for a predetermined time. An algorithm determines whether the AC voltage is a true sine wave or otherwise. The system monitors DC current on the high side, or positive terminal, of a battery. User selectable DC shunts are provided to measure a range of DC currents.

Cross-component measurements made at a plurality of toolface angles are processed to remove bias. The amplitude of the resulting sinusoid is used to estimate a distance to an interface in an earth formation.

A photovoltaic (PV) inverter system operates continuously in a buck converter mode to generate a sum of full wave rectified sine wave currents at a current node common to a plurality of buck converters in response to a plurality of full wave rectified sine wave currents generated via the plurality of buck converters. The PV inverter system increases the level of the voltage sourcing each buck converter when a corresponding DC power source voltage is lower than the instantaneous voltage of a utility grid connected to the PV inverter system.

The invention relates to a square wave three phase brushless permanent magnet dc motor. In order to solve the problems existed in the prior square wave permanent magnet motor and sine wave permanent magnet motor, a magnetic pole number 2P is equal to 8 on a rotor iron core; a slot number Z is equal to 12 of a stator iron core, twelve teeth comprises three big teeth, three middle teeth and six small teeth;a mechanical angle ratio of the big teeth is 50 degree +/- 5 degree, the mechanical angle ratio of the middle teeth is 40 degree +/- 5 degree,the mechanical angle ratio of the small teeth is 15 degree +/- 5 degree,and a total mechanical angle ratio of one big tooth plus one middle tooth plus two small teeth is equal to 120 degree.The three phase concentrated windings respectively wind on the big teeth and middle teeth, each phase only has two concentrated windings and the three phase motor only has six concentrated windings. The motor can generate a stable torque when driven by a three phase square wave current and a torque fluctuation index is equivalent to that of the sine wave permanent magnet. The motor of the invention has a series of advantages of minimum winding end, minimum air gap, minimum material, minimum locating torque and minimum loss or the like.

Coding of an audio signal is provided where an indicator of the frequency variation of sinusoidal components of the signal is used in the tracking algorithm of a sinusoidal coder where sinusoidal parameters from appropriate sinusoids from consecutive segments are linked. By applying an indicator such as a warp factor or polynomial fitting, more accurate tracks are obtained. As a result, the sinusoids can be encoded more efficiently. Furthermore, a better audio quality can be obtained by improved phase continuation.

A drive circuit (18) produces a drive signal for a pump (10) having a piezoelectric actuator (14), with the piezoelectric actuator (14) forming a part of the drive circuit (18) and serving to shape a waveform of the drive signal. The drive circuit (18) comprises a pulse generator (100) which generates pulses; a converter circuit (102) which receives the pulses and produces charge packets at a rate which equals a desired drive frequency; and, the piezoelectric actuator (14). The piezoelectric actuator (14) receives the charge packets and, by its capacitive nature, integrates the charge packets to shape the waveform of the drive signal. Preferably, the piezoelectric actuator (14) integrates the charge packets to yield a drive field that approximates a sine wave. In one non-limiting example embodiment, the pulse generator (100) comprises a microcontroller-based pulsed width modulator (PWM) circuit (116) and the converter circuit (102) comprises a flyback circuit.

A power supply for a Light Emitting Diode (LED) traffic signal that controls the light intensity. The light intensity conforms to a predetermined pattern based on the input voltage root mean square value (V_rms). The input voltage is changed by acting on the amplitude of the sine wave or by using a triac and controlling the angle of fire. The power supply comprises a fuse module, an electromagnetic compatibility filter module, a power supply module, a LED load module, a current monitor module, a RMS-DC conversion module and a fuse blow out module.

A small-sized, low-profile fluid pump having high pumping capabilities includes an actuator and a planar section including a metal plate. The actuator includes a disk-shaped piezoelectric element attached to a disk-shaped diaphragm. As a result of application of a square-wave or sine-wave drive voltage, the actuator performs a bending vibration from the central portion to the peripheral portion. The peripheral portion of the actuator is not restrained. The actuator performs a bending vibration in the state in which it is in proximity to the planar section while facing the planar section. A center vent is provided at or in an area adjacent to the center of an actuator facing area of the planar section that faces the actuator.

A frequency detecting circuit estimates the frequency fp of a propeller shaft based on the frequency fc of vehicle speed pulses, and calculates a control frequency fp′ which is a harmonic of the frequency fp. A basic signal generator generates a basic cosine wave signal xp1 and a basic sine wave signal xp2 of the control frequency fp′. Adaptive filters and an adder generate a control signal Scp for canceling a driveline noise produced in a passenger compartment by the propeller shaft. A speaker outputs a canceling sound based on the control signal Scp into the passenger compartment.

A method and a system is disclosed for providing access in a centralized manner to a communications medium that is suitable for allowing use of a plurality of Home Phoneline Network Association (HPNA) v2 frames. A plurality of messages are transmitted between a first enhanced station and a second enhanced station. Each transmitted message is transmitted in an enhanced frame that has timing to allow an Inter-Frame Gap (IFG). A blocking signal, such as a sine wave signal and a cosine wave signal, is transmitted during at least one IFG between enhanced frames to mask the presence of the IFG to a non-enhanced STA. Alternatively, the blocking signal can be transmitted during at least one reply message. Contention-free access to the communications medium is also provided by transmitting messages in a highest priority level available in an HPNA v2 frame.

In a method and apparatus for controlling power factor correction (PFC) in mixed operation modes, a frequency of the input voltage is obtained by detecting the zero crossing points of the input voltage. A peak of the input voltage is obtained by detecting input voltage with 90 degree phase. Thus, the present invention predicts the input voltage by its frequency and peak and the characteristic of the sine wave. A digital signal processor computes the duty and frequency of a boost switch, switching the operation mode of the boost converter among continuous mode, critical mode and discontinuous mode according to input voltage or the load. According to another aspect, the operation is switched to critical mode from the average current mode when a zero current is detected before the charging and recharging cycle of the boost switch is finished. Overcurrent protection may be achieved by controlling current in response to detected voltage to provide a substantially constant power level. The overcurrent protection may be adaptive in nature. In this aspect, an adaptive driver for a PFC controller reduces the slew rate of signals over the boost switch of the PFC controller. The adaptive driver may have a group of transistors which may be divided into a plurality of branches. The charging current through the boost switch may be increased by turning on an increasing number of branches until the voltage over the switch exceeds a reference voltage, and this may determine the number of branches to drive the boost switch during normal operation.

An apparatus and method for high-resolution reflectometry that operates simultaneously in both the time and frequency domains, utilizing time-frequency signal analysis and a chirp signal multiplied by a Gaussian time envelope. The Gaussian envelope provides time localization, while the chirp allows one to excite the system under test with a swept sinewave covering a frequency band of interest. High resolution in detection of the reflected signal is provided by a time-frequency cross correlation function. The high-accuracy localization of faults in a wire/cable can be achieved by measurement of time delay offset obtained from the frequency offset of the reflected signal. The apparatus enables one to execute an automated diagnostic procedure of a wire/cable under test by control of peripheral devices.

A permanently mounted AC powered control/display unit and a remote sensor for use in measuring ground resistance. The sensor is permanently mounted around the earth grounding cable. The control display unit generates a 1953 Hz, 5 Vac sine wave which is sent via a cable to a 100:1 ratio drive transformer in the remote sensor. The transformer induces a 0.05 Vac sine wave in the ground cable. The resulting current is detected by a 100:1 turns ratio sense transformer. The current is returned via the cable to the control display unit and converted to a voltage, filtered, amplified and rectified by a synchronous rectifier. The rectified voltage is again filtered and presented to an analog to digital converter. A microprocessor reads the output of the analog to digital converter and the ground resistance is computed by using Ohm's Law (R=E/I), the result being shown on a display.

A control device has a unit for preparing a pattern having first and second periods by comparing a triangular wave and a sine wave having an amplitude ratio set at each value of a modulation factor, and selecting one pattern corresponding to an instructed modulation factor, and a unit for applying a controlled voltage, set at low and high levels in response to first and second periods of the selected pattern, to a generator. The triangular wave has a cycle duration obtained by dividing the cycle duration of the generator by product of 3 and odd number, a crest having a level higher than the sine wave at a timing of each first period, and a trough having a level lower than the sine wave at a timing of each second period.

A medical device includes a pattern of electrically conductive material. The pattern of electrically conductive material has an anti-antenna geometrical shape such that the anti-antenna geometrical shape substantially prevents the medical device from creating an imaging artifact and/or substantially allows imaging of a volume within the medical device. The pattern may be formed by multiple “figure-8” shaped electrical conductors, multiple “figure-8” emulating electrical conductors, multiple sine-wave-like shaped electrical conductors, multiple zig-zag patterned electrical conductors, by multiple electrical conductors, each having sequential conductive loops, and/or a single conductor weaved into a loop mesh. The electrically conductive material may be titanium, tantalum, nitinol, stainless steel, and/or NbZr.