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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

[en] SIGNALS INTEGRITY IN HIGH SPEED PRINTED CIRCUIT BOARDS / [pt] INTEGRIDADE DE SINAIS EM PLACAS DE CIRCUITO IMPRESSO DE ALTAS TAXAS

VANESSA PRZYBYLSKI RIBEIRO MAGRI 14 February 2008 (has links)
[pt] Este trabalho tem como objetivo avaliar a viabilidade técnica para fabricação de placas de circuito impresso de múltiplas camadas com espessuras reduzidas mantendo a integridade dos sinais que se propagam em conexões inter- chip, nas taxas de transmissão de 1Gb/s e 10Gb/s para aplicações em redes de comunicações nos padrões 1GB Ethernet e 10GB Ethernet. A avaliação inclui o projeto de uma placa de 6 camadas de planos condutores, com espessura total de 1,29mm. A placa desenvolvida contém linhas de transmissão, vias e curvas, microcapacitores , microresistores e conectores I/O adequados para a faixa de freqüência em questão. / [en] The main purpose of this work is to evaluate the technical reliability to fabricate a Printed circuit board (PCB) with reduced thickness multilayer keeping signal Integrity on inter-chip connections in 1Gb/s and 10Gb/s (1GB Ethernet and 10GB Ethernet network communications). This evaluation includes the development of a PCB project with 06 layers and 1,29mm thickness. The PCB contains several transmission lines, vias, bends, microcapacitors, microresistors, connectors (I/O) suitable to this frequency band.
52

Applications of active materials

Edqvist, Erik January 2009 (has links)
Energy efficiency is a vital key component when designing and miniaturizing self sustained microsystems. The smaller the system, the smaller is the possibility to store enough stored energy for a long and continuous operational time. To move such a system in an energy efficient way, a piezoelectrical locomotion module consisting of four resonating cantilevers has been designed, manufactured and evaluated in this work. The combination of a suitable substrate, a multilayered piezoelectric material to reduce the voltage, and a resonating drive mechanism resulted in a low power demand. A manufacturing process for multilayer cantilever actuators made of P(VDF-TrFE) with aluminum electrodes on a substrate of flexible printed circuit board (FPC), has been developed. An important step in this process was the development of an etch recipe for dry etching the multilayer actuators in an inductive plasma equipment. Formulas for the quasi static tip deflection and resonance frequency of a multilayered cantilever, have been derived. Through theses, it was found that the multilayered structures should be deposited on the polymer side of the FPC in order to maximize the tip deflection. Both a large and a miniaturized locomotion module were manufactured and connected by wires to verify that the three legged motion principal worked to move the structures forward and backward, and turn it right and left. By touching and adding load, to a fourth miniaturized cantilever, its ability to act as a contact sensor and carry object was verified. The presented locomotion module is part of a multifunctional microsystem, intended to be energy efficient and powered by a solar panel with a total volume of less than 25 mm3 and weight 65 mg. The whole system, consisting of a solar cell, an infra red communication module, an integrated circuit for control, three capacitors for power regulating, the locomotion module and an FPC connecting the different modules, was surface mounted using a state of the art industrial facility. Two fully assembled systems could be programmed both through a test connector and through optical sensors in the multifunctional solar cell. One of these was folded together to the final configuration of a robot. However, the entire system could not be tested under full autonomous operating conditions. On the other hand, using wires, the locomotion module could be operated and used to move the entire system from a peak-to-peak voltage of 3.0 V.
53

Testing and evaluation of the integratability of the Senior processor / Testning och evaluering av Senior processorns integrerbarhet

Hedin, Alexander January 2011 (has links)
The first version of the Senior processor was created as part of a thesis projectin 2007. This processor was completed and used for educational purposes atLinköpings University. In 2008 several parts of the processor were optimized andthe processor expanded with additional functionality as part of another thesisproject. In 2009 an EU funded project called MULTI-BASE started, in which theComputer Division at the Department of Electrical Engineering participated in.For their part of the MULTI-BASE project, the Senior processor was selected tobe used. After continuous revision and development, this processor was sent formanufacturing. The assignment of this thesis project was to test and verify the different func-tions implemted in the Senior processor. To do this a PCB was developed fortesting the Senior processor together with a Virtex-4 FPGA. Extensive testingwas done on the most important functions of the Senior processor. These testsshowed that the manufactured Senior processor works as designed and that it alonecan perform larger calculations and use external hardware accelerators with thehelp of its various interfaces. / Den första versionen av Senior processorn skapades som en del i ett examensarbe-te under 2007, denna processor färdigställdes och användes i utbildningssyfte påLinköping Universitet. 2008 optimerades flera delar av processorn och utökadesmed extra funktionalitet som del av ytterligare ett examensarbete. 2009 startadeett EU finansierat projekt vid namn MULTI-BASE, som ISYs Datortekniks avdel-ning deltar i. Till deras del av MULTI-BASE projektet valdes Senior processorn attanvändas, efter ytterligare utveckling skickades denna processor för tillverkning. Detta examensarbete hade i uppgift att testa och verifiera de olika funktionernasom Senior processorn har implementerats med. För att göra detta tillverkades ettkretskort som ska användas för att testa Senior processorn tillsammans med enVirtex-4 FPGA. Utförliga tester gjordes på de viktigaste funktionerna hos Seniorprocessorn, dessa tester visade att den tillverkade Senior processorn fungerar somplanerat. Den kan på egen hand utföra större beräkningar och använda sig avexterna hårdvare acceleratorer med hjälp av sina olika gränssnitt.
54

Design of an Autonomous Underwater Vehicle with Vision Capabilities

Jebelli, Ali January 2016 (has links)
In the past decade, the design and manufacturing of intelligent multipurpose underwater vehicles has increased significantly. In the wide range of studies conducted in this field, the flexibility and autonomy of these devices with respect to their intended performance had been widely investigated. This work is related to the design and manufacturing of a small and lightweight autonomous underwater vehicle (AUV) with vision capabilities allowing detecting and contouring obstacles. It is indeed an exciting challenge to build a small and light submarine AUV, while making tradeoffs between performance and minimum available space as well as energy consumption. In fact, due to the ever-increasing in equipment complexity and performance, designers of AUVs are facing the issues of limited size and energy consumption. By using a pair of thrusters capable to rotate 360o on their axis and implementing a mass shifter with a control loop inside the vehicle, this later can efficiently adapt its depth and direction with minimal energy consumption. A prototype was fabricated and successfully tested in real operating conditions (in both pool and ocean). It includes the design and embedding of accurate custom multi-purpose sensors for multi-task operation as well as an enhanced coordinated system between a high-speed processor and accustomed electrical/mechanical parts of the vehicle, to allow automatic controlling its movements. Furthermore, an efficient tracking system was implemented to automatically detect and bypass obstacles. Then, fuzzy-based controllers were coupled to the main AUV processor system to provide the best commands to safely get around obstacles with minimum energy consumption. The fabricated prototype was able to work for a period of three hours with object tracking options and five hours in a safe environment, at a speed of 0.6 m/s at a depth of 8 m.
55

Tratamento a plasma para melhoria na metalização de placas de circuito impresso / Plasma treatment for improved metallization of printed circuit boards

Laraia, André Bianchi 31 July 2018 (has links)
Submitted by André Bianchi Laraia (andreblaraia@yahoo.com.br) on 2018-08-29T22:49:26Z No. of bitstreams: 1 Dissertacao-Andre-Bianchi-Laraia.pdf: 2142300 bytes, checksum: 9264414d38ac4ce5ec3be46acb98ca44 (MD5) / Rejected by Pamella Benevides Gonçalves null (pamella@feg.unesp.br), reason: Solicitamos que realize correções na submissão seguindo as orientações abaixo: • Necessário fazer ajuste no sumario na lateral direita nas numerações. • A palavra APÊNDICE A deve ser centralizada A palavra APÊNDICE A deve ser centralizada • Referências. A palavra Referências deve ser centralizada, As referencias devem ser justificadas, espaço simples com um espaço simples(enter) entre elas. • Sobre a elaboração das referencias e citações favor solicitar orientação para ajuste com a bibliotecária Pâmella - pamella.benevides@unesp.br • A palavra APÊNDICE A deve ser centralizada Mais informações acesse o link: http://www2.feg.unesp.br/Home/Biblioteca21/diretrizes-2016.pdf Agradecemos a compreensão. on 2018-08-30T12:07:55Z (GMT) / Submitted by André Bianchi Laraia (andreblaraia@yahoo.com.br) on 2018-09-12T01:58:28Z No. of bitstreams: 1 Tese-Andre-Bianchi-Laraia-v20-converted.pdf: 2144718 bytes, checksum: eef37a1c04c8a387ddbff2e31f67db35 (MD5) / Approved for entry into archive by Pamella Benevides Gonçalves null (pamella@feg.unesp.br) on 2018-09-12T17:38:03Z (GMT) No. of bitstreams: 1 laraia_ab_me_guara.pdf: 2144718 bytes, checksum: eef37a1c04c8a387ddbff2e31f67db35 (MD5) / Made available in DSpace on 2018-09-12T17:38:03Z (GMT). No. of bitstreams: 1 laraia_ab_me_guara.pdf: 2144718 bytes, checksum: eef37a1c04c8a387ddbff2e31f67db35 (MD5) Previous issue date: 2018-07-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho apresenta o desenvolvimento de um processo de tratamento com plasma para melhorar ametalização química de placas de circuito impresso (PCI). A pluma de plasma é gerada em argônio a partir da descarga de barreira dielétrica (DBD) promovida entre uma agulha cirúrgica e um cilindro usando capilar de borosilicato como dielétrico. A tensão picoa-pico aplicada foi de 5 kV, com forma de onda senoidal na frequência de 37 kHz e potência de descarga em torno de 765 mW. O substrato é um composto de fibra de vidro e resina epóxi. Com incidência perpendicular da pluma de plasma na superfície, o diâmetro da área tratada circular é de 10 mm. Desta forma, o ângulo de contato reduz de 75 ° a 45 ° com 3 s de interação entre superfície da amostra e a ponta do plasma e o ângulo atinge o mínimo de 33 ° após 180 s de tempo de tratamento. A metalização química foi feita com banhos seqüenciais de solução de paládio e finalizada com banho de solução aquosa de cobre. Testes de adesão padrão mostraram uma forte adesão das camadas de metal nas superfícies previamente tratadas com as plumas de plasma. Esta adesão melhora com o tempo de tratamento. A melhoria na metalização foi observada em superfície plana e também em furos usados para conectar diferentes camadas em PCIs. A área metalizada na superfície dos buracos é maior nos orifícios tratados. Quanto maior o tempo de tratamento, maior é essa área. Todos os resultados indicaram que a técnica de tratamento por plasma de placas de fibra de vidro melhora a sua metalização química pelo cobre, levando a uma adesão mais uniforme e eficaz do metal à superfície com um método ambientalmente amigável / This work reports the development of a plasma treatment process to improve the chemical metallization of printed circuit boards (PCB). The plasma plume is generated in argon from a dielectric barrier discharge (DBD) promoted between a surgical needle and a cylinder using a borosilicate capillary as dielectric. The applied peak-to-peak voltage was 5 kV, with sinusoidal waveform at 37 kHz frequency and power in the discharge around 765 mW. The substrate was a composite of fiberglass and epoxy resin. With perpendicular incidence of the plasma plume on the surface the diameter of the circular treated area was 10 mm. In this area the contact angle reduces from 75° to 45° with 3 s of the plasma-surface interaction and the angle reaches the minimum of 33° after 180 s of treatment time. Chemical metallization was made with sequential baths of solution of palladium and finished with bath of aqueous solution of copper. Standard adhesion tests showed a strong adhesion of the metal layer on surfaces previously treated with the plasma plumes. This adhesion improves with the treatment time. The improvement in the metallization was observed on flat surface and also in holes used to connect different layers in PCB’s. The metallized area on the surface of the holes is larger in treated holes. The longer the treatment time the larger is this area. All these results indicated that the technique of plasma treatment of fiberglass boards improves its chemical metallization by copper leading to a more uniform and effective adhesion of the metal to the surface with an environmental friendly method
56

Étude multicritère pour l'enfouissement partiel ou total de convertisseurs d'électronique de puissance dans un circuit imprimé / Multi-criteria study for partial or complete Printed Circuit Board embedding of power electronic converters

Pascal, Yoann 22 October 2019 (has links)
Les travaux présentés dans ce manuscrit traitent de l’enfouissement dans un circuit imprimé de convertisseurs de puissance, paradigme visant l’insertion de composants électroniques au sein du circuit imprimé.Une structure simple et économique de composant inductif enfoui, pouvant être employé comme inductance, coupleur, ou résonateur monolithique, est tout d’abord décrite. Un modèle analytique complet est développé. Des prototypes sont réalisés, validant le modèle et démontrant l’intérêt de la topologie.L’agencement des composants de puissance constituant une cellule de commutation est ensuite étudié. En particulier, un modèle analytique permettant une compréhension intuitive des mécanismes oscillatoires dans le cadre de l’emploi de transistors rapides est décrit.Une technique de reprise de contact de face avant pour puce enfouie, basée sur un morceau de mousse pressée, est proposée. Une étude préliminaire, à forte composante expérimentale, est présentée. Elle démontre que certains prototypes enfouis présentent des caractéristiques électriques et une fiabilité similaires à celles obtenus avec des fils de bonding.Enfin, les résultats de l’étude sur l’agencement des composants d’une cellule de commutation sont appliqués pour concevoir et réaliser un hacheur basé sur des transistors SiC connectés par mousse pressée. La structure délivre 3 kW sous 600 V en continu, démontrant la viabilité du procédé de reprise de contact proposé. / This thesis deals with Printed-Circuit Board (PCB) embedding of power converters, paradigm according to which electronic components are placed within the substrate itself.First, a simple and economical structure of inductive component, which can be used either as an inductor, a coupler, or a monolithic resonator, is described. A comprehensive analytical model is developed. Prototypes are manufactured, validating the analytical model and highlighting the value of the topology.The arrangement of the power components of a switching cell is then studied. In particular, an analytical model offering an intuitive understanding of the oscillation mechanisms in cells using fast transistors is proposed.A simple and economical top-side connection technic for PCB-embedded power dies using a pressed piece of metal foam is described. A preliminary study, with strong experimental component, is proposed. It shows that the embedded prototypes have electrical performances and a reliability close to that of wire-bonded dies.Finally, the results from the study on the arrangement of the components of a switching cell are used to design and manufacture a chopper based on SiC transistors connected using a piece of pressed metal foam. This chopper proved to be able to continuously deliver 3 kW under 600 V to a load, thereby validating the proposed top-side connection technic.
57

Integration of a 3.3 kW, AC/DC bidirectional converter using printed circuit board embedding technology / Intégration d'un convertisseur 3.3 kW, AC/DC, bidirectionnel en utilisant la technologie d'enfouissement PCB

Caillaud, Rémy 17 January 2019 (has links)
Les énergies fossiles (Pétrole, Charbon, …) représentent 80 % des énergies consommés. Malheureusement pour l’environnement, elles sont les plus polluantes. Le remplacement actuel des énergies fossiles permet au marché de l’électronique de puissance de grandir d’année en année. L’électronique de puissance permet d’adapter l’énergie électrique à son utilisation finale. Dans la pratique, l’adaptation de l’énergie électrique utilise des convertisseurs. En plus de respecter le volume, l’efficacité et la fiabilité imposés par le cahier des charges pour chaque application, l’électronique de puissance doit aussi permettre de réduire sensiblement les coûts. Le convertisseur doit assurer le fonctionnement électrique du circuit, le support mécanique des composants et la gestion thermique. Le package utilisé par les nouveaux composants à grand gap limite leurs performances. L’intégration des convertisseurs doit développer des méthodes d’interconnexion permettant d’éliminer ce package. L’objectif de la recherche sur l’intégration des convertisseurs est de repousser les limites imposées par un cahier des charges standard tout en assurant ces 3 fonctions principales. Parmi les nombreuses techniques d’intégration, le circuit imprimé (PCB) est mature industriellement, permet la fabrication collective et un assemblage automatisé. L’intégration utilisant le PCB a développé la technique d’enfouissement de puce avec laquelle la puce est directement enfouie dans le PCB sans son package. Cette thèse va étudier la méthode d’enfouissement pour les autres composants nécessaires à la réalisation d’un convertisseur (Condensateurs, Composants Magnétiques). Une optimisation du convertisseur qui doit être réalisé permet de prendre en compte les avantages de cette nouvelle technologie. Un prototype de convertisseur intégré a été réalisé avec des composants utilisant cette technologie. / With the endangering of the environment due to the use of fossil fuels, the power electronics market is growing through the years. The number of applications is increasing in numerous field as, for example, transport (electric car, "more electric" aircraft) or energy (photovoltaic, smart grid). Beyond meeting the volume, efficiency and reliability specifications for each application, power electronics should also reduce substantially costs. Today, the managing of the electric energy uses power electronic converters. The conception of a converter is a multiphysic problem. The converter has to ensure electrical functionality, mechanical support and proper thermal management.The new wide-band gap components are limited in performance by their package. The integration of a converter should use new interconnection methods to avoid the use of packaged components. The trend is to integrate the maximum of components into a single system. This integration can offer benefits such as size and weight reduction, cost saving and reliability improvement by managing the complexity and the high density of interconnection. Among many integration technologies available, Printed Circuit Board (PCB) is well known in the industry, allowing mass production with automated manufacturing and assembly. The PCB integration was developed with the “Die Embedding” technology in which a bare die in embedded directly in the PCB to not use package. This thesis studied the embedding technology on others components necessary to the realization of a converter (Capacitors, Magnetics, …). An optimization of the converter is done taking into account the advantages of this new technology. A prototype of an AC/DC bidirectional converter fully integrated using this technology was realized.
58

Využití termochromních systémů pro testování distribuce tepla / Using thermochromic systems for testing heat distribution

Klimeš, Jan January 2017 (has links)
This thesis deals with principles of thermochromism and its possible applications in heat distribution testing. Theoretical part describes mechanisms which allow the thermochromic properties of the substances. Particular attention is paid to cholesteric liquid crystals. Ability to measure the heat for this type of liquid crystals was varified. Also long service life in high humidity environment, enviroment with intense UV radiation, cyclic changes in temperature or immersion in water was tested. A possibility of their practical use in diagnosis was verified as well. Specifically mapping of heat distribution on an assembled PCB. Conclusion contains comparison and evaluation of this method in terms of accuracy, user comfort and economic advantages compared to conventional infrared sensors.
59

Zařízení pro automatické měření voltampérových charakteristik / Device for automatic measurement of volt-ampere characteristics

Ondráček, Petr January 2020 (has links)
The Master's thesis discusses the design and realization of electronic meter of volt-ampere characteristics using Wifi module ESP32. The device is designed to be able to measure the characteristic in the voltage range of +/- 20 V and current range of +/- 200 mA. The device is controlled by web interface. The user is able to connect to it with for example his or her smartphone. This interface enables the user to configure various parameters, including the range of measurement and the power restriction. Furthermore, it is possible to graphically display the measured characteristic and export the data. To be independent on the outer network, the ESP32 is operated as an access point, which is creating a new simple network without the internet connection. In the Master's thesis, the principle of voltage and current measurement is explained theoretically, the circuit connection of device and the printed circuit board are designed and the cover of the device is modeled. Also the process of creating the device according to the design is described and the cover of the device is printed on 3D printer. After that, the control program is designed, described and uploaded into the resulting device. Finally, the functionality of the device is tested by measuring the volt-ampere characteristics of a few components.
60

Vestavěná řídicí jednotka pro ovládání laboratorního zařízení / Embedded Control Unit for Instrumentation of Laboratory Appliance

Voda, Zbyšek January 2020 (has links)
Aim of this thesis is modular design of control system for Golem device, which is used for drug research. Several modules with specified controlled area were designed. They communicate using CAN bus and are controlled by Raspberry Pi computer. The thesis includes PCB design and control firmware for modules, backend application for Raspberry Pi, which provides application interface, and simple protocol used for communication between modules. Designed system was tested in simulated environment.

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