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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.
11

Investigation into the pedagogical value of demonstrating deliberate design deficiencies in PCB design instruction

Sunedal, Björn January 2021 (has links)
Universities and other higher education institutions have been struggling with high levels of student dropouts and poor graduation rates for a long time. As a result, there has been an interest in modifying traditional teaching techniques and implementing new ones to improve student learning outcomes. Interactive Lecture Demonstrations (ILD) is one such teaching technique which has shown positive results in terms of improving student learning outcomes. An audio recorder and player application with the addition of a DC/DC converter was developed. Six different PCB versions of the audio application were created, containing different combinations of deliberate design deficiencies. The deliberate design deficiencies came in the form of different configurations of decoupling capacitors and ground planes. The DC/DC converter served as a noise source to expose weaknesses in the design. In order to make certain that design deficiencies were exposed effectively, the conversion frequency of the DC/DC converter was switchable between a "high" and a "low" setting. The "low" conversion frequency setting was chosen to comfortably fall in the frequency range of human hearing. Measurements of voltage (time domain and spectral), current spectrum, audio spectrum and radiated emissions were collected. Audio recordings illustrating the impact of decoupling capacitors and interference from the DC/DC converter were performed. The measurement results and audio recordings were used to produce an ILD in video format. The ILD was structured around a modified version of the PODS (Predict-Observe-Discuss-Synthesize) model, which is a four-step process used in ILDs. The ILD contained four separate demonstrations that covered the impact of decoupling capacitors, ground topology and the DC/DC converter on the audio quality and radiated emissions. The ILDs were presented in such a way that the measurement results and audio recordings were correlated with the underlying design theory. Students who had taken either one of two courses related to PCB and electronics design offered at the Royal Institute of Technology (KTH) in the spring of 2019 and 2020 were invited to view the ILD video. The effectiveness of the ILD presentation in terms of pedagogic value was measured via a survey which the students were asked to fill out after watching the video. The results were overall very positive. The feedback received indicate that the students found the demonstrations to be informative and educational. By being able to see and hear the effects of neglecting good PCB design practices in two key areas, the demonstrations were able to provide a more realistic and real-world view of the consequences of neglecting to adhere to good design practices in these two areas that may not be apparent in the theoretical literature. In addition, since PCB design is such a vast subject, the results motivates further developments and study of the ILD concept related to other PCB design concepts such as transmission lines, layer ordering, signal integrity (crosstalk, timing, noise, etc), and others. / Universitet och andra högre lärosäten har länge kämpat mot höga nivåer av studentavhopp och låg genomströmning. Som en följd av detta har det funnits ett intresse att göra förändringar i de traditionella undervisningsmetoderna samt att implementera nya sådana. Interaktiva föreläsningsdemonstrationer (Interactive Lecture Demonstrations, ILD) är en undervisningsmetod som har visat på positiva resultat gällande studenters förmåga att uppnå läromålen. En ljudinspelnings- och uppspelningstillämpning med en likspänningsomvandlare konstruerades. Sex olika kretskort med en kombination av olika avsiktliga konstruktionsbrister producerades. De avsiktliga konstruktionsbristerna innefattade olika kombinationer av avkopplings-kondensatorer och jordplan. Likspänningsomvandlaren agerade som en störningskälla vars syfte var att blottlägga svagheter i konstruktionen. För att säkerställa att konstruktionsbristerna skulle kunna blottläggas tydligt var omvandlingsfrekvensen på likspänningsomvandlaren ställbar mellan ”hög” och ”låg”. Omvandlingsfrekvensen på inställningen ”låg” valdes så att den med god marginal hamnade inom frekvensområdet för mänsklig hörsel. Matningar av spänning (tids- och frekvensdomän), strömspektrum, ljudspektrum och utstrålad radioenergi genomfördes. Ljudinspelningar som belyste inverkan av avkopplings-kondensatorerna och störningar från likspänningsomvandlaren samlades in. Mätningarna och ljudinspelningarna användes för att producera en ILD i videoformat. ILD:erna konstruerades kring en modifierad version av PODS-modellen (Predict- Observe- Discuss- Synthesize, ung. Förutspå-Observera-Diskutera-Inlärning), vilken är en fyrstegsprocess för ILD:er. ILD:en innehöll fyra separata demonstrationer som belös avkopplingskondensatorernas, jordtopologins och likspänningsomvandlarens inverkan på ljudkvaliteten och den utstrålade radioenergin. ILD:en presenterades på ett sådant sätt att mätresultaten och ljudinspelningarna korrelerades till den bakomliggande konstruktionsteorin. Studenter som hade läst endera av två kurser relaterade till kretskorts- och elektronik-konstruktion vid Kungliga Tekniska högskolan (KTH) under våren 2019 och 2020 mottog en inbjudan att titta på videon. Utvärdering av effektiviteten hos ILD-presentationen gällande dess pedagogiska värde gjordes via en enkät vilka studenterna ombads att fylla i efter att de tittat på videon. Resultatet var övervägande positivt. Återkopplingen tyder på att studenterna tyckte att demonstrationerna var informativa och lärorika. Genom att kunna se effekterna av att försumma god PCB-konstruktionssed inom två nyckelområden så lyckades demonstrationerna ge en mer realistisk syn på konsekvenserna av att inte följa god konstruktionssed på ett sätt som inte är uppenbart i den teoretiska litteraturen. Eftersom att PCB-konstruktion är ett så pass omfattande ämnesområde så motiverar resultaten vidare utveckling och studier av ILD-konceptet inom andra PCB-konstruktionskoncept, t.ex transmissionsledningar, lager-ordning, signalintegritet (¨överhörning, timing, brus, etc), samt andra.
12

Design and implementation of a high-speed PCI-Express bridge

Börjesson, Mandus, Gerner, Håkan January 2019 (has links)
This master thesis will cover the prestudy, hardware selection, design and implementation of a PCI Express bridge in the M.2 form factor. The thesis subject was proposed by WISI Norden who wished to extend the functionality of their hardware using an M.2 module. The bridge fits an M-Key M.2 slot and has the dimensions 80x22 mm. It is able to communicate at speeds up to 8 Gb/s over PCI Express and 200 Mbit/s on any of the 20 LVDS/CMOS pins. The prestudy determined that an FPGA should be used and a Xilinx Artix-7 device was chosen. A PCB was designed that hosts the FPGA as well as any power, debugging and other required systems. Associated proof-of-concept software was designed to verify that the bridge operated as expected. The software proves that the bridge works but requires improvement before the bridge can be used to translate sophisticated protocols. The bridge works, with minor hardware modifications, as expected. It fulfills all design requirements set in the master thesis and the FPGA firmware uses a well-established protocol, making further development easier.
13

Design of a parallel A/D converter system on PCB : For high-speed sampling and timing error correction / Kretskortskonstruktion av system med parallella A/D omvandlare : För höghastighetssampling och korrigering av tidsfel.

Alfredsson, Jon January 2002 (has links)
The goals for most of today’s receiver system are sampling at high-speed, with high resolution and with as few errors as possible. This master thesis describes the design of a high-speed sampling system with"state-of-the-art"components available on the market. The system is designed with a parallel Analog-to-digital converter (ADC) architecture, also called time interleaving. It aims to increase the sampling speed of the system. The system described in this report uses four 12-bits ADCs in parallel. Each ADC can sample at 125 MHz and the total sampling speed will then theoretically become 500 Ms/s. The system has been implemented and manufactured on a printed circuit board (PCB). Up to four boards can be connected in parallel to get 2 Gs/s theoretically. In an approach to increase the systems performance even further, a timing error estimation algorithm will be used on the sampled data. This algorithm estimates the timing errors that occur when sampling with non-uniform time interval between samples. After the estimations, the sampling clocks can be adjusted to correct the errors. This thesis is concerning some ADC theory, system design and PCB implementation. It also describes how to test and measure the system’s performance. No measurement results are presented in this thesis because measurements will be done after this project. The last part of the thesis discusses future improvementsto achieve even higher performance.
14

Design of a parallel A/D converter system on PCB : For high-speed sampling and timing error correction / Kretskortskonstruktion av system med parallella A/D omvandlare : För höghastighetssampling och korrigering av tidsfel.

Alfredsson, Jon January 2002 (has links)
<p>The goals for most of today’s receiver system are sampling at high-speed, with high resolution and with as few errors as possible. This master thesis describes the design of a high-speed sampling system with"state-of-the-art"components available on the market. The system is designed with a parallel Analog-to-digital converter (ADC) architecture, also called time interleaving. It aims to increase the sampling speed of the system. The system described in this report uses four 12-bits ADCs in parallel. Each ADC can sample at 125 MHz and the total sampling speed will then theoretically become 500 Ms/s. The system has been implemented and manufactured on a printed circuit board (PCB). Up to four boards can be connected in parallel to get 2 Gs/s theoretically. </p><p>In an approach to increase the systems performance even further, a timing error estimation algorithm will be used on the sampled data. This algorithm estimates the timing errors that occur when sampling with non-uniform time interval between samples. After the estimations, the sampling clocks can be adjusted to correct the errors. </p><p>This thesis is concerning some ADC theory, system design and PCB implementation. It also describes how to test and measure the system’s performance. No measurement results are presented in this thesis because measurements will be done after this project. The last part of the thesis discusses future improvementsto achieve even higher performance.</p>
15

Odhad parametrů jezdce na vozítku segway a jejich použití pro optimalizaci řídícího algoritmu / Segway driver parameter estimation and its use for optimizing the control algorithm

Dobossy, Barnabás January 2019 (has links)
Táto práca sa zaoberá vývojom, testovaním a implementáciou adaptívneho riadiaceho systému pre dvojkolesové samobalancujúce vozidlo. Adaptácia parametrov vozidla sa uskutoční na základe parametrov vodiča. Parametre sústavy sa nemerajú priamo, ale sú odhadované na základe priebehu stavových premenných a odozvy sústavy. Medzi odhadované parametre patrí hmotnosť a poloha ťažiska vodiča. Cieľom práce je zabezpečiť adaptáciu jazdných vlastností vozidla k rôznym vodičom s rôznou hmotnosťou, kvôli zlepšeniu stability vozidla. Táto práca je pokračovaním predchádzajúcich projektov z roku 2011 a 2015.
16

Rozvinutí elektroniky a softwaru na robotickém vozidle Car4 / Developement of electronics and software on robotic vehicle Car4

Michal, Mikuláš January 2021 (has links)
Tato diplomová práce se zabývá revizí elektroniky robotického vozidla car4 se zaměřením na měření rychlosti otáčení kol, výkonovou a řídicí elektroniku. Car4 posloužilo jako základ pro již přes 20 diplomových prací od roku 2010. To znamenalo, že některé základní aspekty car4 byly zastaralé. Bylo vytvořeno schéma elektroniky vozidla, které bylo dále využito pro vývoj a výrobu nového hardwaru. Komponenty byly poté otestovány a implementovány na vozidlo. Dále byl vytvořen kinematický model 4WS vozidla za použití Ackermanovy geometrie, který byl implenetován a otestován na car4. Dále by měl sloužit jako základ řídicího algoritmu pro budoucí vývoj car4.
17

Návrh elektroniky pro řízení dvoukolového nestabilního vozidla / Design of control unit for two-wheeled self-balancing vehicle

Bastl, Michal January 2015 (has links)
This diploma thesis is a part of a project of two students. The aim of the project is to design safer electronics for the unstable balancing vehicle HUMMER and implementation of advanced diagnostics and fault detection. In the first part of the project we analysed the original vehicle using the FMEA analyse and created a new concept of the vehicle. The second part of the project describes a new hardware. I designed and tested the power electronics, control unit and supplies. The outputs of the work are prototypes which allow testing a new concept.
18

Comparison Study and Product Development using Wireless Narrowband Low-power Wide-area Network Technologies

Ortis Pasamontes, Enrique January 2017 (has links)
Nowadays it is more clear that the Internet of things (IoT) is not a transient trend but a completely new industry. The internet of things has the capability to enhance current industries (Industry 4.0), as well as to help protecting the environment and people. The latter is the case with the system developed and described in this thesis. The possibilities that IoT brings are due to the interconnection of heterogeneous embedded devices to the internet. This thesis focus on LPWANs (Low Power Wide Area Networks), which is a new set of technologies specifically design for the needs of IoT devices.Due to the recent deploy of NB-IoT (Narrow Band IoT) networks it has become more difficult to know what LPWAN is best for a certain application. Thus, the first half of this thesis involves the comparative study of NB-IoT and LoRaWAN LPWANs. This comparison required an in depth study of each technology, specially on the physical and datalink layers. The comparison briefly displays the main characteristics of each technology and explain the main conclusions in a concise manner. The second part of the thesis describes the development of a GNSS tracker. This tracker will be used on train wagons carrying goods that are dangerous for people and the environment. This thesis report describes the different steps taken, from the requirement specification to the partial development of the software.
19

Cost Optimized Radio-over-Fiber System

Damas, Jacqueline 06 February 2024 (has links)
The demand of smaller and portable electronic devices has contributed to the realisation of compact embedded systems using PCB miniaturization techniques. The commercial market is faced with competition of handheld users’ devices in medical, communication and automotive industries which are smaller and lighter electronic devices. The possibilities of higher degree of integration in planar technology using cost effective electronic components has lead to different art of design and fabrication of compact units. In this work, a central station and a base station front-end with small form factor have been realized using commercial components on PCBs. These electronic compacts units were integrated in the IF-over-Fiber system architecture. The IF-over-Fiber architecture comprised of miniaturized electronic components for quadrature modulation and upconversion. The central station supports multi-Gbps data rate modulation formats in order to increase the spectral efficiency of the transmitted information. Multilevel modulation formats are considered spectrally efficient and can double the transmission capacity by transmitting more information in the amplitude, phase, polarization or a combination of all. The BS front-end comprises of the 60 GHz upconverter and a 60 GHz planar 2×2 microstrip antenna. The 10 GHz IF carrier allows an optical transmission with higher spectral efficiency in optical domain, as well as it is less susceptible to dispersion induced power fading inherent in optical fiber. Characterization of the designed central station and base station front-end through measurements are presented and discussed. The IF-over-Fiber system analysis is made for the 2 Gbps QPSK transmission with respect to error vector magnitude (EVM), eye and constellation diagrams.
20

Design of Resonant Converters using Silicon Carbide Power

Moozhikkal, Rahul January 2016 (has links)
The design of series-loaded resonant converters using the state of the art SiC power transistorsis investigated in the thesis. SiC devices are chosen as they offer lower switching losses comparedto conventional Si based devices A very detailed study about the working and differentmodes of operation of the resonant converter is carried out. The thesis further explains how thehigh speed switching capabilities of the SiC devices remain untapped owing to the presence ofstray inductances in the switch-snubber layout. A comparison of all the commercially availableSiC devices are carried out to find the most suitable switch for the resonant converter. Thethesis also carries out a very detailed step by step design of the circuit and the PCB layout forthe resonant converter. Two different layouts are proposed and then compared for their strayinductance and power losses. Finally, based on the experiments the thesis validates the suitabilityof using discrete SiC power transistors in place of power modules. / Utformningen av serie-belastade resonansomvandlare med hjälp av toppmoderna SiC högeffekttransistorernaundersöks i denna avhandlingen. SiC-enheter väljs eftersom de erbjuderlägre switch-förluster jämfört med konventionella Si-baserade enheter.En mycket detaljeradstudie om funktionen och de olika operationella tillstånden hos resonansomvandlare utförs.Avhandlingen förklarar vidare hur förmågan till högfrekvent switchning hos SiC-enheterförblir ofullständigt utnyttjad på grund av förekomsten av ströinduktanser i switch-snubberlayouten.En jämförelse av alla kommersiellt tillgängliga SiC-enheter genomförs för att hittaden mest lämpliga switchen för resonansomvandlaren. Avhandlingen utförs också en mycketdetaljerad steg-för-steg-utformning av resonansomvandlaren kretsschema och kretskortlayout.Två olika layouter föreslås och jämförs därefter utifrån deras ströinduktanser ocheffektförluster. Slutligen, baserat på experimentella resultat bekräftar avhandlingen.Lämpligheten att använda diskreta SiC-effekttransistorer istället för effektmoduler medintegrerade drivarsteg för styrelektroderna.

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