Sine wave

About: Sine wave is a research topic. Over the lifetime, 12183 publications have been published within this topic receiving 93013 citations. The topic is also known as: sinusoid.

Processing of acoustic waveforms

Abstract: A sinusoidal model for acoustic waveforms is applied to develop a new analysis/synthesis technique which characterizes a waveform by the amplitudes, frequencies, and phases of component sine waves. These parameters are estimated from a short-time Fourier transform. Rapid changes in the highly-resolved spectral components are tracked using the concept of "birth" and "death" of the underlying sine waves. The component values are interpolated from one frame to the next to yield a representation that is applied to a sine wave generator. The resulting synthetic waveform preserves the general waveform shape and is perceptually indistinguishable from the original. Furthermore, in the presence of noise the perceptual characteristics of the waveform as well as the noise are maintained. The method and devices disclosed herein are particularly useful in speech coding, time-scale modification, frequency scale modification and pitch modification.

Biosensor apparatus and method with sample type and volume detection

Abstract: A biosensor apparatus and method with sample type and cell volume detection. The apparatus includes a sine wave generator to apply an AC signal to a biosensor cell containing a sample, a current-to-voltage converter, a phase shifter, a square wave generator, a synchronous demodulator, and a low pass filter which yields a signal proportional to the effective capacitance across the biosensor cell, which is proportional to the volume of the sample. In addition, the current-to-voltage converter yields a signal indicative of the type of sample contained within the biosensor cell. The method includes applying a sine wave to the biosensor cell, shifting the phase of the resultant signal, generating a square wave synchronous with the sine wave, demodulating the resultant signal with the square wave, and filtering the demodulated signal to produce a signal proportional to the effective capacitance across the biosensor cell. The biosensor apparatus and method are capable of determining sample type and measuring glucose levels over a wide range of sample volumes.

Metal detection method, metal detection device, metal detection method for wireless power supply device, and wireless power supply device

Abstract: Provided are a metal detection method, a metal detection device, a metal detection method for a wireless power supply device, and a wireless power supply device which are capable of accurately detecting whether an object is a metal or a nonmetal. An oscillation circuit (10) oscillates and produces a sine wave having a single fundamental frequency, and excites a metal detection coil (Ls) by the oscillation current (It) of the sine wave. An electromagnetic wave of the sine wave having the single fundamental frequency is radiated from the metal detection coil (Ls). A high-pass filter circuit (11a) receives the oscillation current (It), removes the fundamental frequency component from the oscillation current (It), and extracts a high-harmonic component of the fundamental frequency. A comparison circuit (12) determines the presence or absence of a metal.

A new impedance spectrometer for the investigation of electrochemical systems

Abstract: The development of a computer‐controlled electrochemical impedance spectrometer, based on a Fourier transform algorithm is described. Together with a fast potentiostat the system can be used in the frequency range 1 mHz to 100 kHz. The perturbation signal is a superposition of sine waves with properly chosen frequencies. The overall measurement time is limited only by the lowest frequency in the spectrum and by the data transfer to the computer, thus, time‐resolved impedance spectra measurements can be performed. The principle of operation and technical details are presented and discussed.

PWM technique for power MOSFET inverter

Abstract: A sinusoidal PWM (pulsewidth-modulated) inverter suitable for use with power MOSFETs is described. The output waveforms in the proposed PWM inverter are investigated both theoretically and experimentally. A modulating signal for the three-phase PWM inverter is obtained by adding the harmonic components of integer multiples of three to the three-phase sine waves. By using the proposed modulating signal, the amplitude of the fundamental component is increased about 15% more than that of a conventional sine-wave inverter and the commutation number of the inverter is decreased to two-thirds of a conventional one. >