Single Sine Wave Research Articles

Utilization of Single Phase Pure Sine Wave Inverters in Electrical Energy Conversion Systems for Solar Panels with Variable Loads

The inverter built in this research is used to convert direct current into alternating current with a size of 3000 watts, which has a DC input voltage of 24 volts. This inverter has a large capacity and can generate enough electricity to run different huge electrical devices or several units at once. It's made utilizing energy-efficient technology to cut down on energy waste during conversion. Furthermore, safeguards such voltage surge and overcurrent prevention guarantee the operational safety of the inverter. The inverter was built using the PWM method and variable loads (resistive load, inductive load and capacitive load), with the aim of evaluating the inverter's ability to handle resistive, inductive and capacitive loads and to see how the inverter responds to load changes dynamically. Based on observations and calculations, higher loads are positively correlated with higher inverter power and efficiency. The inverter has a max output of 664.62 watts and 229 Volt is the output voltage attained. This demonstrates that the EGS002 PSW inverter produces AC voltage of high quality with precise and steady characteristics.

Active vibration control of flexible beam system based on cuckoo search algorithm

<p>A flexible beam is recognized as a lightweight structure that is prone to excessive vibration, resulting in poor performance. Thus, controlling unwanted vibration is necessary to maintain the system’s performance. Therefore, this study presents a technique to suppress undesired vibration in a flexible beam structure by introducing active vibration control (AVC). However, to develop an effective controller, an appropriate flexible beam model must first be obtained. In recent times, one of the best methods employed to model a flexible beam structure is system identification via a swarm intelligence algorithm. In this study, an intelligent algorithm acknowledged as cuckoo search (CS) was acquainted. The capability of the proposed algorithm was verified using three robustness techniques which were correlation test, pole-zero diagrams and mean square error (MSE). The simulation result showed that the CS algorithm achieved superior performance by achieving the lowest MSE of 6.1547x10<sup>-9</sup>, a correlation test between a 95% confidence level and high stability. Next, a proportional-integral-derivative (PID) controller tuned by the Ziegler-Nichols method was developed using the transfer function accomplished from the CS model. Two types of interference, namely single and multiple sine waves were introduced to validate the effectiveness of the controller. The controller successfully achieved a 30.2 dB of attenuation level for both disturbances.</p>

A time-interleaved ADC calibration technique for spectrum monitoring applications

A fully background estimation and calibration technique to reduce the spur powers caused by time-interleaved ADC architecture is presented. The estimations of mismatches are succeeded using easily generated calibration signals. The implementation details for the mismatch estimations and calibrations are provided using a 2.8 GSPS ADC and a FPGA device. Continuous operation of the spectrum monitoring applications is allowed while the mismatch estimation and the calibration process in progress. The offset mismatch calibration is realized using an adder circuit at the background and more than 10 dB spur power reduction is obtained from the proposed method. A digital multiplier circuit is used to realize the gain calibration. The timing skew calibration is fulfilled by the addition of a small offset to the DDS (Direct Digital Synthesizer) phase offset of DDC (Digital Down Converter). It is possible to get more than 6 dB power reduction at some critical spur signals after the application of proposed timing mismatch calibration technique when a single tone sine wave input is applied.

The Effect of Pore-Scale Two-Phase Flow on Mineral Reaction Rates

In various natural and engineered systems, mineral–fluid interactions take place in the presence of multiple fluid phases. While there is evidence that the interplay between multiphase flow processes and reactions controls the evolution of these systems, investigation of the dynamics that shape this interplay at the pore scale has received little attention. Specifically, continuum scale models rarely consider the effect of multiphase flow parameters on mineral reaction rates or apply simple corrections as a function of the reactive surface area or saturation of the aqueous phase, without developing a mechanistic understanding of the pore-scale dynamics. In this study, we developed a framework that couples the two-phase flow simulator of OpenFOAM (open field operation and manipulation) with the geochemical reaction capability of CrunchTope to examine pore-scale dynamics of two phase flow and their impacts on mineral reaction rates. For our investigations, flat 2D channels and single sine wave channels were used to represent smooth and rough geometries. Calcite dissolution in these channels was quantified with single phase flow and two phase flow at a range of velocities. We observed that the bulk calcite dissolution rates were not only affected by the loss of reactive surface area as it becomes occupied by the non-reactive non-aqueous phase, but also largely influenced by the changes in local velocity profiles, e.g., recirculation zones, due to the presence of the non-aqueous phase. The extent of the changes in reaction rates in the two-phase systems compared to the corresponding single phase system is dependent on the flow rate (i.e., capillary number) and channel geometry, and follows a non-monotonic relationship with respect to aqueous saturation. The pore-scale simulation results highlight the importance of interfacial dynamics in controlling mineral reactions and can be used to better constrain reaction rate descriptions in multiphase continuum scale models. These results also emphasize the need for experimental studies that underpin the development of mechanistic models for multiphase flow in reactive systems.

Analytical Optimal Load Calculation of RF Energy Rectifiers Based on a Simplified Rectifying Model.

Wireless power transfer (WPT) is an essential enabler for novel sensor networks such as the wireless powered communication network (WPCN). The efficiency of an energy rectifier is dependent on both input power and loading condition. In this work, to maximize the rectifier efficiency, we present a low-complexity numerical method based on an analytical rectifier model to calculate the optimal load for different rectifier topologies, including half-wave and voltage-multipliers, without needing time-consuming simulations. The method is based on a simplified analytical rectifier model based on the diode equivalent circuit including parasitic parameters. Furthermore, by using Lambert-W function and the perturbation method, closed-form solutions are given for low-input power cases. The method is validated by means of both simulations and measurements. Extensive transient simulation results using different diodes (Skyworks SMS7630 and Avago HSMS285x) and frequency bands (400 MHz, 900 MHz, and GHz) are provided for validation of the method. A 400 MHz 1- and 2-stage voltage multiplier are designed and fabricated, and measurements are conducted. Different input signals are used when validating the proposed methods, including the single sinewave signal and the multisine signal. The proposed numerical method shows excellent accuracy with both signal types, as long as the output voltage ripple is sufficiently low.

Simulation Research on Acoustic Detection Technology of Buried PE Pipes

Polyethylene (PE) pipe has been widely used in gas transportation pipeline system because it overcomes the shortcomings of non-corrosion resistance of metal pipelines. However, the stiffness and strength of PE pipe are small, and it is easy to be destroyed in the third-party construction process. Moreover, PE pipe is not electrically or magnetically conductive, and it is unable to use the developed metal pipe detection method, which has brought great security risks. Urban gas pipeline accidents occur frequently, and the situation during the production is complex and severe. Therefore, it is of great significance to study how to effectively realize the detection of underground PE pipe. This paper verifies the feasibility of the acoustic method from the perspective of simulation. Firstly, it studies the influence of buried pipe depth on the received signal of geophone. Secondly, it studies the influence of buried pipe size on the received signal of PE geophone with a certain depth Finally, it studies the received signal of geophone when PE pipe is in mixed soil. The simulation results show that the method based on acoustic wave is suitable, the signal source emits a sweeping frequency single tone sine wave, which propagates to the target and is reflected. A string of geophones on the ground measure the velocity of the surface vibration. Given the propagation rate of wave in the material, time delay can be used between signal sent and received on the ground to obtain the estimated distance to the target.

Design a Half Bridge Inverter and a Full Bridge Inverter with Overload Protection Circuit Using IC555

Inverter is a power electronic circuit that converts the direct voltage (DC) to an alternating voltage (AC). Inverters are used in a range of applications from consumer electronics and industrial to renewable energy. The flexible capability to create an AC signal from a DC voltage, frequency and speed control are all accomplished from the use of Inverter. Inverter takes the voltage and passes it through switching elements which turn the DC signal into an AC square wave signal. This wave is then passes through filter which turns it into a sine wave signal of the required voltage. This paper presents design an inverter with overcurrent protection circuit without microcontroller, where the MOSFET gate driver is controlled by pulses generated from 555 timer, and with using a low pass filter and setup transformer, a low cost sine wave inverter has been obtained. The heart of the design is 555 timer. The design is achieved in Proteus 8. Simulation results demonstrated that a single phase sine wave (50 Hz) has been generated by a half bridge inverter and a full bridge inverter and protection circuit from current higher than 4.5A has been built. The reliability and accuracy of the system are verified through an experiment.

Consideration on Input Signal for ADC Histogram Test in Short Time

This paper describes two algorithms for generating test signals to efficiently test the linearity of ADCs. Linearity is an important testing item for ADCs, and it takes a long time (hence is costly) to test especially low-sampling-rate, high-resolution ADCs. We have proposed to generate a test signal consisting of multiple-sine waves, to precisely test the linearity for specific important codes (such as around the center of the output codes), using an arbitrary waveform generator (AWG) and an analog filter in our previous studies. Here, we formulate them for general use. Their verification is performed on a single sine wave, and good results are obtained to show the validity of the derivation algorithm.

Spectral Variability of VHS J1256–1257b from 1 to 5 μm

Abstract Multiwavelength time-resolved observations of rotationally modulated variability from brown dwarfs and giant exoplanets are the most effective method for constraining their heterogeneous atmospheric structures. In a companion paper, we reported the discovery of strong near-infrared variability in HST/WFC3/G141 light curves of the very red L-dwarf companion VHS J1256–1257b. In this paper, we present a follow-up 36 hr Spitzer/IRAC Channel 2 light curve together with an in-depth analysis of the Hubble space telescope (HST) and the Spitzer data. The combined data set provides time-resolved light curves of VHS1256b sampling 1.1 to 4.5 μm. The Spitzer light curve is best fit with a single sine wave with a period of 22.04 ± 0.05 hr and a peak-to-peak amplitude of 5.76 ± 0.04%. Combining the period with a previously measured projected rotational velocity ( ), we find that VHS1256b is most consistent with equatorial viewing geometry. The HST/G141+Spitzer spectral energy distribution favors a model with a of 1000 K and low surface gravity with disequilibrium chemistry. The spectral variability of VHS1256b is consistent with predictions from partly cloudy models, suggesting that heterogeneous clouds are the dominant source of the observed modulations. We find evidence at the 3.3σ level for amplitude variations within the 1.67 μm CH4 band, which is the first such detection for a variable L-dwarf. We compare the HST/G141 time-resolved spectra of three red L-dwarfs with high-amplitude near-infrared rotational modulations and find that although their time-averaged spectra are similar, their spectroscopic variabilities exhibit notable differences. This diversity reinforces the advantage of time-resolved spectroscopic observations for understanding the atmospheres of brown dwarfs and directly imaged exoplanets.

A Method on Detecting the Positional Deviation of the Light Beam by using a Single Sine Wave

A Method on Detecting the Positional Deviation of the Light Beam by using a Single Sine Wave

Sound quality degradation of audio equipment by hum noise induced by non-audible high frequency electrical noise

In recent audio equipment, induction and inflow of non-audible high frequency (HF) electrical noise to audio equipment is increasing more and more due to implementation of personal computer / network connectivity and high-resolution capability in digital audio equipment. In this study, in order to investigate another causes of influence of non-audible HF electric noise on playback sound, we measured a loudspeaker output of an audio amplifier by the audio analyser with inputting single HF sine wave from a function generator to analog input of the audio amplifier. From measured results, it was found that the power of harmonics of 60 Hz (hum noise) on the loudspeaker output of some audio amplifiers increased when single HF sine wave was inputted. Tendency of the increasing of the hum noise component depended on the frequency of the inputted sine wave and model of audio amplifier. These results show the importance of consideration of HF characteristic and countermeasure to the HF noise also in circuit design and tuning of audio equipment.

Synchronous radio-frequency FM signal generator using direct digital synthesizers.

A novel Radio-Frequency Frequency-Modulated (RF-FM) signal generation method is introduced and a prototype circuit developed to evaluate its functionality and performance. The RF-FM signal generator uses a modulated, voltage-controlled time delay to correspondingly modulate the phase of a 10 MHz sinusoidal reference signal. This modulated reference signal is, in turn, used to clock a Direct Digital Synthesizer (DDS) circuit resulting in an FM signal at its output. The modulating signal that is input to the voltage-controlled time delay circuit is generated by another DDS that is synchronously clocked by the same 10 MHz sine wave signal before modulation. As a consequence, all of the digital components are timed from a single sine wave oscillator that forms the basis of all timing. The resultant output signal comprises a center, or carrier, frequency plus a series of phase-synchronized sidebands having exact integer harmonic frequency separation. In this study, carrier frequencies ranging from 10 MHz to 70 MHz are generated with modulation frequencies ranging from 10 kHz to 300 kHz. The captured spectra show that the FM signal characteristics, amplitude and phase, of the sidebands and the modulation depth are consistent with the Jacobi-Anger expansion for modulated harmonic signals.

PID controller design to generate pulsatile flow rate for in vitro experimental studies of physiological flows.

Producing accurate pulsatile flow rates is essential for many in vitro experimental studies in biofluid dynamics research. A controller system was developed to control a flow loop to produce easily adjustable pulsatile flow rates with sufficient accuracy. An Arduino board is used as a micro-controller to control a pump to produce various pulsatile flow rates, and an open-source proportional-integral-derivative (PID) control algorithm is developed for this purpose. Four non-trivial pulsatile waveforms were produced by the PID controller, as well as an iterative controller, and the performance of both controllers was evaluated. Both the PID and iterative controllers were able to successfully produce slowly-varying signals (single and multi-harmonic low frequency sine waves), but for high frequency signals where the flow has strong acceleration/deceleration (e.g. for physiological waveforms) the iterative controller exhibited significant undershoot. The comparison of PID and iterative controllers suggests that if the desired flow rate is a low frequency, simple waveform then the iterative controller is preferred due to simplicity of implementation. However, if the desired signal is rapidly changing and more complicated then the PID controller achieves better results. This system can be implemented in many flow loops due to its simplicity and low cost, and does not require a mathematical model of the system.

Light-responsive organic flashing electron ratchet

Ratchets are nonequilibrium devices that produce directional motion of particles from nondirectional forces without using a bias, and are responsible for many types of biological transport, which occur with high yield despite strongly damped and noisy environments. Ratchets operate by breaking time-reversal and spatial symmetries in the direction of transport through application of a time-dependent potential with repeating, asymmetric features. This work demonstrates the ratcheting of electrons within a highly scattering organic bulk-heterojunction layer, and within a device architecture that enables the application of arbitrarily shaped oscillating electric potentials. Light is used to modulate the carrier density, which modifies the current with a nonmonotonic response predicted by theory. This system is driven with a single unbiased sine wave source, enabling the future use of natural oscillation sources such as electromagnetic radiation.

Modelling ac voltammetry with MECSim: facilitating simulation–experiment comparisons

Summary Here we introduce the Monash Electrochemistry Simulator (MECSim) software package that allows most aspects of ac voltammetry to be simulated when a single sine wave or a combination of sine waves are superimposed onto a dc ramp. The MECSim software and companion tool kits can be downloaded free of charge from http://www.garethkennedy.net/MECSim.html where there is also instructional documentation. Features accommodated in the simulation model include non-linear background capacitance, uncompensated resistance, Butler–Volmer and Marcus–Hush electron transfer, chemical reactions involving surface confined and solution phase species and stationary or rotating disc electrode mass transport with linear diffusion. Companion tool kits are also provided that allow Fourier transformed ac voltammograms with harmonic analysis to be generated along with other forms of data presentation. The MECSim format in combination with parameter optimisation tool kit also facilitates the implementation of sophisticated forms of experiment-theory comparisons needed to estimate the electrode kinetic and other parameters. MECSim software is computationally efficient and based on flexible code that can be used in cluster computing as well as on a single machine. Typical simulations take seconds to run on a laptop and parameter searches needed to tackle the inverse problem can be achieved efficiently. Capabilities of MECSim are illustrated in this article by comparing simulated results with those obtained experimentally.

Finite volume numerical solution to a blood flow problem in human artery

In this paper, we solve a one dimensional blood flow model in human artery. This model is of a non-linear hyperbolic partial differential equation system which can generate either continuous or discontinuous solution. We use the Lax–Friedrichs finite volume method to solve this model. Particularly, we investigate how a pulse propagates in human artery. For this simulation, we give a single sine wave with a small time period as an impluse input on the left boundary. The finite volume method is successful in simulating how the pulse propagates in the artery. It detects the positions of the pulse for the whole time period.

Binocular combination of stimulus orientation.

When two sine waves that differ slightly in orientation are presented to the two eyes separately, a single cyclopean sine wave is perceived. However, it is unclear how the brain calculates its orientation. Here, we used a signal detection rating method to estimate the perceived orientation when the two eyes were presented with Gabor patches that differed in both orientation and contrast. We found a nearly linear combination of orientation when both targets had the same contrast. However, the binocular percept shifted away from the linear prediction towards the orientation with the higher contrast, depending on both the base contrast and the contrast ratio. We found that stimuli that differ slightly in orientation are combined into a single percept, similarly for monocular and binocular presentation, with a bias that depends on the interocular contrast ratio. Our results are well fitted by gain-control models, and are consistent with a previous study that favoured the DSKL model that successfully predicts binocular phase and contrast combination and binocular contrast discrimination. In this model, the departures from linearity may be explained on the basis of mutual suppression and mutual enhancement, both of which are stronger under dichoptic than monocular conditions.

A novel sine wave modulation method of pulse current during double wire MIG welding

As a highly efficient welding method that guarantees good weld quality, double wire pulse welding has broken the neck bottle of single wire welding in terms of weld speed and tackled such problems as undercut and hump during single wire high-speed welding. During double wire welding, double current waveform modulation is a key that affects weld quality and efficiency. Based on single wire sine wave modulation, this paper proposes a new double wire sine wave modulation method. Front and back wire pulse currents with the same peak value and basic current variation amplitude were obtained by performing sine wave modulation on ordinary double current pulse waveform. An in-depth analysis was made in terms of the energy distribution coefficient m, amplitude coefficient k, and the negative half-cycle sine wave pulse number Nn to discuss how double wire sine wave modulation affects weld seam imaging quality. Experimental results show that with the application of sine wave modulation, double wire pulse welding can effectively enhance instantaneous energy density and broaden the energy variation range between pulse current base value and peak value. Also, enhancing weld speed appropriately helps to improve weld quality and efficiency to a great extent.

Modulation of Auditory Spatial Attention by Angry Prosody: An fMRI Auditory Dot-Probe Study

Emotional stimuli have been shown to modulate attentional orienting through signals sent by subcortical brain regions that modulate visual perception at early stages of processing. Fewer studies, however, have investigated a similar effect of emotional stimuli on attentional orienting in the auditory domain together with an investigation of brain regions underlying such attentional modulation, which is the general aim of the present study. Therefore, we used an original auditory dot-probe paradigm involving simultaneously presented neutral and angry non-speech vocal utterances lateralized to either the left or the right auditory space, immediately followed by a short and lateralized single sine wave tone presented in the same (valid trial) or in the opposite space as the preceding angry voice (invalid trial). Behavioral results showed an expected facilitation effect for target detection during valid trials while functional data showed greater activation in the middle and posterior superior temporal sulci (STS) and in the medial frontal cortex for valid vs. invalid trials. The use of reaction time facilitation [absolute value of the Z-score of valid-(invalid+neutral)] as a group covariate extended enhanced activity in the amygdalae, auditory thalamus, and visual cortex. Taken together, our results suggest the involvement of a large and distributed network of regions among which the STS, thalamus, and amygdala are crucial for the decoding of angry prosody, as well as for orienting and maintaining attention within an auditory space that was previously primed by a vocal emotional event.

Effects of Geometric Imperfections on Flexural Buckling Resistance of Laterally Braced Columns

AbstractThis paper deals with the effects of geometric imperfections on flexural inelastic buckling resistance of axially loaded columns with equally spaced lateral braces and presents a simplified way of forming the critical geometric imperfection for finite-element analyses, which leads to rational results for buckling resistances. First, laterally braced columns with geometric imperfections formed by the traditional single half sine wave or the eigenbuckling modes were analyzed by FEM to illustrate the effect of different imperfection shapes. Second, geometric imperfections of columns acquired from measurements in laboratory tests were adopted, and the statistical characteristic and probability distribution of initial deflections along the column length were obtained; then, extensive numerical results from finite-element analyses were obtained through random imperfection simulations. Last, the comparison was made between statistical results based on the random imperfections and those based on eigenbuck...