6029 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.

A regulated power factor corrected power supply apparatus is provided. The apparatus includes an input rectifier circuit for receiving an input AC voltage and outputting a full-wave rectified DC voltage. A single-stage isolated buck-type converter is coupled with the input circuit. The converter circuit comprises an isolated buck-type converter circuit including an isolation transformer. An output rectifier and semiconductor tap switch are coupled to a secondary winding of the isolation transformer. The tap switch couples a larger portion of the secondary winding to an output bulk capacitor during the portions of the input sinewave half-cycle, which are low in amplitude. The tap switch enables the single-stage isolation buck-type converter to operate over a much larger portion of the input sinewave, but also allows the converter to operate at high-efficiency over the majority of the input sinewave.

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.

A low-noise laser diode module comprises a laser diode for emitting light with a wavelength in the range from UV to IR, a drive circuit for injecting electrical current into said diode, and an automatic power control circuit for monitoring and adjusting laser output power using front-facet photodiode external to the laser assembly and a feedback loop. Said drive circuit produces injection current modulated by an RF signal with variable degrees, depending on the wavelength to be stabilized, the desired spectral bandwidths of the laser output, and/or other applications. Said RF signal can be a sine wave, a distorted sine wave, a rectified sine wave, a non-sine wave, a series of narrow pulses, or repetitive shunt. The present invention encompasses a method for producing stable, broadband, and low-coherent laser. The present invention also encompasses a method for producing stable narrowband or single longitudinal mode laser. The present invention further encompasses a compact light source applicable to DPSS lasers, fiber lasers, optical parametric oscillators, low-speckle laser display systems, and seeders, with or without nonlinear frequency conversion processes.

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.