Spelling suggestions: "subject:"pulse wider modulation""
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Digitální nízkofrekvenční zesilovač s univerzálními vstupy / Digital audio amplifier with universal inputsSvadbík, Pavel January 2012 (has links)
This diploma thesis deals with digital audio amplifier with universal inputs and its design. The first part describes modulation and audio formats for audio electronics. The thesis contain design of a block diagram of the digital audio amplifier and describes the requirements for functional blocks. As a basic device for audio signal processing was choosen integrated circuit STA326. The thesis continue with circuits design for each blocks with a description of their principles. The next section describes the construction and firmware for microcontroller. The last part of this diploma thesis is targeted on the presentation of the measured parameters of the amplifier. The conclusion summarizes the results that have been achieved and advantages and disadvantages of the digital audio amplifier prototype.
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Audio výkonový zesilovač ve třídě D s mikroprocesorovým řízením / Class D audio power amplifier with microprocessor controllingNedbal, Jan January 2012 (has links)
The thesis deals with the design and practical realization of class D audio power amplifier with microprocessor controlling. The first part describes the integrated circuits used in a preamplifier and his complete design with a description of the control program for ATmega128 microcontroller. The following part describes an integrated power amplifier TAS5613 and his circuits. The next section describes a switching power supply design using integrated circuit TOP261EN. The last section describes measurements of parameters of individual parts of the amplifier.
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Přechodové děje na výstupu LTI systému druhého řádu se spojitým časem řízeného pulsně šířkovou modulací / Transient effect at the output of a continuous-time LTI second order system controlled pulse-width modulationPetera, Martin January 2016 (has links)
The aim of this thesis is to determine the size of overshoot produced at the output of a linear continuous second order system controlled by pulse width modulation depending on the period and duty cycle of the modulation and system parameters. This thesis contains analytic calculation of the size of overshoot produced at the output of the second order system with damping ratio > 0, except the damping ratio equals to 1 (i.e. both underdamped and damped system) depending on period and duty cycle of the modulation. This thesis also includes a comparison of partial analytic results to numerical simulation in Matlab program and also with measurement at second order system model.
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Impact of Overmodulation Methods on Inverter and Machine Losses in Voltage-Fed Induction Motor DrivesMahlfeld, Hannes, Schuhmann, Thomas, Döbler, Ralf, Cebulski, Bernd 15 August 2023 (has links)
The modulation methods Space Vector PWM (SVPWM), Discontinuous PWM (DPWM1, DPWMMAX) and six-step mode are investigated in the overmodulation range of a voltage-fed induction motor drive. This area enables an increase of inverter output voltage so that drive performance can be enhanced. Though, pulse dropping occurs which results in increased iron losses and current waveform quality
degradation. Due to differences in harmonic distortion the modulation methods cause various torque oscillations and power losses in induction motors and inverter drives. To quantify these effects in a squirrel cage induction motor drive a simulation model containing a finite element machine model and an analytic inverter model is developed, in order to find the PWM scheme offering maximum torque and minimal power losses. Additionally, the holistic investigation of machine and inverter losses allows for making statements concerning total losses of drive systems and the most suitable overmodulation scheme for the application.
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Modeling And Simulation Of All-electric Aircraft Power Generation And ActuationWoodburn, David 01 January 2013 (has links)
Modern aircraft, military and commercial, rely extensively on hydraulic systems. However, there is great interest in the avionics community to replace hydraulic systems with electric systems. There are physical challenges to replacing hydraulic actuators with electromechanical actuators (EMAs), especially for flight control surface actuation. These include dynamic heat generation and power management. Simulation is seen as a powerful tool in making the transition to all-electric aircraft by predicting the dynamic heat generated and the power flow in the EMA. Chapter 2 of this dissertation describes the nonlinear, lumped-element, integrated modeling of a permanent magnet (PM) motor used in an EMA. This model is capable of representing transient dynamics of an EMA, mechanically, electrically, and thermally. Inductance is a primary parameter that links the electrical and mechanical domains and, therefore, is of critical importance to the modeling of the whole EMA. In the dynamic mode of operation of an EMA, the inductances are quite nonlinear. Chapter 3 details the careful analysis of the inductances from finite element software and the mathematical modeling of these inductances for use in the overall EMA model. Chapter 4 covers the design and verification of a nonlinear, transient simulation model of a two-step synchronous generator with three-phase rectifiers. Simulation results are shown
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First Order Self-Oscillating Class-D Circuit with Triangular Wave InjectionCarroll, Matthew J 01 June 2021 (has links) (PDF)
An investigation into performance improvements to the modulator stage of a class-D amplifier is conducted in this thesis. Two of the standard topologies, namely class-D open-loop pulse-width modulation (PWM), and the improved self-oscillating feedback system are benchmarked against a topology which includes both a hysteretic comparator in a feedback loop and triangle wave injection. Circuit performance is analyzed by comparing how the triangle injection circuit handles known issues with open-loop and self-oscillating circuits. Using this analysis, it is shown that the triangle injection topology offers an improved power supply rejection ratio relative to open-loop PWM and reduces distortion generated by frequency modulation characteristic of the self-oscillating topology.
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A Novel Two-Level Inverter Design for Efficient Energy Conversion in a Maglev Train RailZetterström, Oskar, Westholm, Stefan West January 2023 (has links)
This report covers the construction of a prototype inverter system designed to power the rail of a maglev train, from component selection through simulations and power demands to mounting and wiring the components into a cabinet. The inverter is made with insulated gate bipolar transistors controlled with pulse-width modulated signals provided by a custom microcontroller. The output of the inverter is a controllable three-phase square wave. The prototype was tested with a microcontroller designed for a different gate driver, making it necessary to design and create an adapter to be able to test it. The results showed that an inverter of two-level topology, together with capacitors, is a viable option for a 10 kHz switching frequency. / Denna rapporten täcker konstruktionen av en prototyp till en inverter topologi designad för att driva rälsen till ett maglevtåg. Från komponentval genom simulering och kapacitetskrav, till montering och sladdragning av komponenterna in i ett skåp. Invertern är gjort med bipolär-transistorer med isolerat syre (IGBTer) som styrs med en pulsbreddsmodulerad signal försedd av en egendesignad mikrokontroller. Utsignalen från invertern är en styrbar trefas fyrkantsvåg. Prototypen skulle testas med en mikrokontroller designad för en annan gate driver, därför var det nödvändigt att designa och producera ett adapterkort för att kunna köra testerna. Resultated visade att en två-level inverter, tillsammans med kondensatorer, är en genomförbar lösning för 10 kHz switchingfrekvens.
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CONTROL OF MULTILEVEL CONVERTERS FOR VOLTAGE BALANCING AND FAULT-TOLERANT OPERATIONSSaha, Aparna, Saha January 2017 (has links)
No description available.
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A microcontroller-based Electrochemical Impedance Spectroscopy Platform for Health Monitoring SystemsBhatnagar, Purva 16 October 2015 (has links)
No description available.
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Development of an Intelligent Sprayer to Optimize Pesticide Applications in Nurseries and OrchardsChen, Yu 15 December 2010 (has links)
No description available.
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