scholarly journals Design and Development of Non-Linearly Controlled Class-D Audio Amplifier

Electronics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 77
Author(s):  
Sridhar Joshi ◽  
Ravi Tripathi ◽  
Manoj Badoni ◽  
Rajeev Kumar ◽  
Pawan Khetrapal

A systematic and simple approach to develop a 20 W audio frequency range switch mode amplifier is presented in this paper. A non-linear sliding mode (SM) technique-based low cost analog controller enables the realized amplifier to deliver highly linear and efficient operation throughout the audio frequency spectrum. The theoretical aspects and practical limitations in the design and realization of subsystems, such as the signal conditioning stage, power stage and sliding mode controller, are considered, while the viable solution is also stated and justified. The hardware realization scheme is also elaborated, based on which the laboratory prototype is fabricated. Hardware results with a 4 Ω resistive load are given on which the performance of the amplifier is evaluated. The total harmonic distortion (THD) below 1% and 73% efficiency at peak load make the amplifier well suited for high quality audio application.

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 232 ◽  
Author(s):  
Intissar Moussa ◽  
Adel Khedher ◽  
Adel Bouallegue

Applied tests on a real photovoltaic panel for a consolidated analysis require complex experiment setup and permanent availability of climatic conditions. This method is ineffective and can damage the PV system. As a result, PV emulators are highly requested in solar energy conversion and generation research, which rests essentially on a maximum power point tracking control algorithm (MPPT) and an adapting power stage as the DC-DC converter and PV inverter. The PV emulator guarantees a controllable light source environment to act as a real PV system in the laboratory. This paper deals with the study and development of an experimental PV emulator based on logarithmic approximation of the ideal single diode model (ISDM), which is implemented using analog electronic components. Mainly, the PV model, the controller, and the power stages, forming the PV emulator, are described. This simple, low-cost, and efficient device is considered as a nonlinear power supply template replacing the real PV system for any operating point irrespective of the environmental condition changes. The emulated current-voltage and power-voltage curves are validated via resistive load and batteries. Then, the performance of the proposed PV emulator is evaluated by its ability to recharge properly two 12V 7 Ah batteries.


Author(s):  
Akram Qashou ◽  
Sufian Yousef ◽  
Abdallah A. Smadi ◽  
Amani A. AlOmari

AbstractThe purpose of this paper is to describe the design of a Hybrid Series Active Power Filter (HSeAPF) system to improve the quality of power on three-phase power distribution grids. The system controls are comprise of Pulse Width Modulation (PWM) based on the Synchronous Reference Frame (SRF) theory, and supported by Phase Locked Loop (PLL) for generating the switching pulses to control a Voltage Source Converter (VSC). The DC link voltage is controlled by Non-Linear Sliding Mode Control (SMC) for faster response and to ensure that it is maintained at a constant value. When this voltage is compared with Proportional Integral (PI), then the improvements made can be shown. The function of HSeAPF control is to eliminate voltage fluctuations, voltage swell/sag, and prevent voltage/current harmonics are produced by both non-linear loads and small inverters connected to the distribution network. A digital Phase Locked Loop that generates frequencies and an oscillating phase-locked output signal controls the voltage. The results from the simulation indicate that the HSeAPF can effectively suppress the dynamic and harmonic reactive power compensation system. Also, the distribution network has a low Total Harmonic Distortion (< 5%), demonstrating that the designed system is efficient, which is an essential requirement when it comes to the IEEE-519 and IEC 61,000–3-6 standards.


Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6041
Author(s):  
Fredy A. Valenzuela ◽  
Reymundo Ramírez ◽  
Fermín Martínez ◽  
Onofre A. Morfín ◽  
Carlos E. Castañeda

A DC motor velocity control in feedback systems usually requires a velocity sensor, which increases the controller cost. Additionally, the velocity sensor used in industrial applications presents several disadvantages such as maintenance requirements and signal conditioning. In this work, we propose a robust velocity control scheme applied to a DC motor based on estimation strategies using a sliding-mode observer. This means that measurements with mechanical sensors are not required in the controller design. The proposed observer estimates the rotational velocity and load torque of the motor. The controller design applies the exact-linearization technique combined with the super-twisting algorithm to achieve robust performance in the closed-loop system. The controller validation was carried out by experimental tests using a workbench, which is composed of a control and data acquisition Digital Signal Proccessor board, a DC-DC electronic converter, an interface board for signals conditioning, and a DC electric generator connected to an adjustable resistive load. The simulation and experimental results show a significant performance of the proposed control scheme. During tests, the accuracy, robustness, and speed response on the controller were evaluated and the experimental results were compared with a classic proportional-integral controller, which uses a conventional encoder.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4239
Author(s):  
Salam J. Yaqoob ◽  
Adel Obed ◽  
Rana Zubo ◽  
Yasir I. A. Al-Yasir ◽  
Hussein Fadhel ◽  
...  

The single-stage flyback Photovoltaic (PV) micro-inverter is considered as a simple and small in size topology but requires expensive digital microcontrollers such as Field-Programmable Gate Array (FPGA) or Digital Signal Processor (DSP) to increase the system efficiency, this would increase the cost of the overall system. To solve this problem, based on a single-stage flyback structure, this paper proposed a low cost and simple analog-digital control scheme. This control scheme is implemented using a low cost ATMega microcontroller built in the Arduino Uno board and some analog operational amplifiers. First, the single-stage flyback topology is analyzed theoretically and then the design consideration is obtained. Second, a 120 W prototype was developed in the laboratory to validate the proposed control. To prove the effectiveness of this control, we compared the cost price, overall system efficiency, and THD values of the proposed results with the results obtained by the literature. So, a low system component, single power stage, cheap control scheme, and decent efficiency are achieved by the proposed system. Finally, the experimental results present that the proposed system has a maximum efficiency of 91%, with good values of the total harmonic distortion (THD) compared to the results of other authors.


2021 ◽  
Author(s):  
Yang Yang ◽  
Xilu Zhao ◽  
Ichiro Hagiwara

Abstract In the crash collision, the vehicle energy absorbers play an important role in the energy absorbed performance. Current vehicle energy absorbers have two defects during collision, such as only 70 % collapsed in its length and high initial peak load. It is because present energy absorbed column is the most primitive from the point of Origami structure. We developed the column so called Reversed Spiral Origami Structure; RSO which solves these 2 defects. However, for RSO, the manufacturing cost of hydroforming in the existing technology is too expensive to be applied in real vehicle structure. To address the problems, we have developed a new molding method called “Partial-heating torsion molding method”. And we have developed RTO (Reversed Torsion Origami Structure) by this new molding method at a very low cost. We show this RTO also solves the two defects of the present vehicle absorbers by not only simulation but also experiments. This structure is possible to replace conventional energy absorbers and it is expected to be widely used such as not only in automobile structures but also in building ones.


2021 ◽  
pp. 0309524X2110605
Author(s):  
Mohamed Bendaoud

This paper presents an approach to design the sliding mode control for an AC-DC converter, consisting of a diode rectifier in series with a boost converter. The results obtained show that this converter with the proposed control law can be used to control the extraction of mechanical power when connecting the permanent magnet synchronous generator (PMSG) to a wind turbine. The boost converter operates in discontinuous conduction mode (DCM) in order to reduce the total harmonic distortion (THD) of the currents in the PMSG. To verify the performance of the proposed method, a simulation study is performed.


Author(s):  
Akashdeep Bhardwaj

This article describes how the rise of fog computing to improve cloud computing performance and the acceptance of smart devices is slowly but surely changing our future and shaping the computing environment around us. IoT integrated with advances in low cost computing, storage and power, along with high speed networks and big data, supports distributed computing. However, much like cloud computing, which are under constant security attacks and issues, distributed computing also faces similar challenges and security threats. This can be mitigated to a great extent using fog computing, which extends the limits of Cloud services to the last mile edge near to the nodes and networks, thereby increasing the performance and security levels. Fog computing also helps increase the reach and comes across as a viable solution for distributed computing. This article presents a review of the academic literature research work on the Fog Computing. The authors discuss the challenges in Fog environment and propose a new taxonomy.


Proceedings ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 25
Author(s):  
Paulo Afonso Ferreira Junior ◽  
Fernando de Souza Campos ◽  
Bruno Albuquerque de Castro ◽  
José Alfredo Covolan Ulson ◽  
Fabrício Guimarães Baptista ◽  
...  

Energy harvesting engineering fields constitutes a promising area to provide electrical power for low-power electric applications obtained from other sources of energy available in the environment such as thermal, electromagnetic, vibrational and acoustic by using transducers. Vibrational sources stand out as a main alternative to be used for generating electric power in sensor nodes in microelectronic devices due to the greater energy conversion efficiency and the use of a simple structure. The cantilever is the main system implemented in studies of obtaining electric energy from vibrations using piezoelectric transducers. Most of piezoelectric transducers in the literature are not yet commercially available and/or are difficult to access for purchase and use. This paper proposes the characterization of low-cost piezoelectric transducers, configured as sensors, for Energy Harvesting applications using three different sizes of circular piezoelectric transducers (PZTs.) with diameters of 3.4 cm, 2.6 cm and 1.5 cm. For all three different PZTs, it was found that the maximum power transfer occurs for a resistive load of 82 kΏ. The maximum power generated in the load for the three PZTs was 40 uW, 14 uW and 1.4 W; with RMS voltages of 2.8 V, 2.10 V and 0.6 V; an acceleration of 1.3 g and a vibration frequency approximate of 7 Hz.


2013 ◽  
Vol 284-287 ◽  
pp. 1841-1845
Author(s):  
Shiuh Jer Huang ◽  
Wei Han Chang ◽  
Janq Yann Lin

Here a low cost embedded robotic gripper with force control function is designed for frangible fruit manipulation. This embedded control gripper is integrated with a Mitsubishi robot based on FPGA control structure. The model-free intelligent fuzzy sliding mode control strategy is employed to design the position controller of each joint and gripper force controller, respectively. Experimental results of pick-and-place frangible small tomato and banana fruit are shown by pictures to evaluate this embedded position/force hybrid control system performance.


2016 ◽  
Vol 62 (2) ◽  
pp. 187-196
Author(s):  
Karim El khadiri ◽  
Hassan Qjidaa

Abstract A class-D audio amplifier with analog volume control (AVC) for portable applications is proposed in this paper. The proposed class-D consist of two sections. First section is an analog volume control which consists of an integrator, an analog MUX and a programmable gain amplifier (PGA). The AVC is implemented with three analog inputs (Audio, Voice, FM). Second section is a driver which consists of a ramp generator, a comparator, a level shifter and a gate driver. The driver is designed to obtain a low distortion and a high efficiency. Designed with 0.18 um 1P6M CMOS technology, the class-D audio amplifier with AVC achieves a total root-mean-square (RMS) output power of 0.5W, a total harmonic distortion plus noise (THD+N) at the 8-Ω load less than 0.06% and a power efficiency of 90% with a total area of 1.74 mm2.


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