The aim of this thesis is to study the possibilities of controlling high-brightness white LEDs using circuits operating at high voltages. The job itself is a division of existing light sources and mainly focus on semiconductor technology LED. The following describes the voltage of DC / DC and AC / DC. The work contains a description of the three high-voltage inverters are designed for power LEDs. Finally, it created a draft scheme of the PCB. As a control circuit is chosen ATMEGA 162 microcontroller from Atmel and source for LED diode is formed HV9910 and HV9861 circuits.

This diploma thesis is about design and realization of universal control unit of technologic processes in food-processing industry. The main goal of this work is to create a device, which will be able with respect to desired values and using measured data autunomusly regulate output. In this work was done the realization of the control unit both from hardware and software aspect. Designed control unit is able to change the output power according to measured temperature. Furthermore is able to control of 2 relays. To set up the desired values and control of relays is used PC software.

Tento projekt zkoumá vybrané způsoby implementace víceúrovňových měničů do praxe. V předložené práci je do hloubky prezentována tzv. ANPC (Active Neutral Point Clamped) pětiúrovňová topologie. Autor se v práci zaměřuje zejména na návrh technického řešení experimentálního vzorku a implementaci řídicích algoritmů jako jsou aktivní řízení napětí na pomocném kondenzátoru nebo aktivní balancování vstupního kapacitního děliče. Pro aplikaci zmíněných struktur byl vybrán moderní digitální integrovaný obvod, který slučuje mikroprocesor a FPGA do jednoho systému. Výsledný měnič umožňuje autonomní provoz a umožňuje generovat přesné a stabilní výstupní napětí.

Over the past few years, the use of LEDs within the automotive and avionic industries has increased due to their high efficiency, durability and wide range of light brightness. As the use of LEDs within these industries grows, a need for reliable, high performance drivers becomes more relevant. Companies are implementing LEDs for applications involving adaptive lighting or simple dimming features. This thesis shows implementation of various non-isolated analog converters integrated with digital dimmers to achieve these adaptive lighting systems. Adaptive lighting systems involve reading an input from an external source (brake pedal or steering wheel) and changing the brightness and/or pattern of the brake/headlights to convey more information to the driver and their surroundings. The analog converters will implement Linear Technology’s LED driver IC’s, while the digital dimmers comprise of microcontrollers and discrete components. The design, simulation, and hardware verification will showcase the abilities of these analog converters. Results will demonstrate the proposed applications for both adaptive front and brake lighting.

Multifunctional voltage source converters (VSCs) are desired for shipboard power systems. The opportunity to extend the functionality of a particular VSC on demand, combined with power system reconfiguration strategies may provide desired redundancy to back up power electronic converters that might be destroyed as a result of a battle damage or material casualty. The space for power electronics may be downsized if the VSCs are capable of performing multiple functions. In addition, the flexibility of the energy management can be enhanced in shipboard power systems if a single VSC can perform multiple functions. The functionality of a VSC in many cases is restricted to a single task or set of tasks by its control architecture. Despite the great number of different control strategies suggested for VSCs, nearly all use similar methods for generation of the reference signals. These methods generally depend upon the use of filters to extract reference signals for the components that are to be injected into or drawn from the system. These methods of control are not flexible. The main objective of the dissertation is the development of a flexible reference signal generator for VSCs that allows online maximization of its possible functions. Furthermore, the switching frequency of a VSC is generally above 10 kHz for many applications, and carries a significant amount of high frequency noise. This necessitates the use of EMI filters, which carry an extra cost and increase the overall bulk of the power electronics. This may not be acceptable for shipboard power systems, where the space and weight requirements are usually stringent. Thus, in addition to investigation of various reference signal generator (RSG) strategies for VSCs, alternative solutions to attenuate EMI levels in the shipboard power system environment are explored.

No description available.

No description available.

The effect of flexible panels on a spacecraft during attitude movement may induce problems if not correctly accounted for in the control system for the spacecraft. The aim of this thesis is to find and evaluate, control algorithms that could be suitable for the Kinesthetic Node and Autonomous Table-Top Emulator (KNATTE) with two flexible mock-up solar panels during an attitude movement of 20 degrees. A simulation model of KNATTE was derived in a previous thesis where a Linear– quadratic–Gaussian (LQG) controller was also found, after a literature review the secondary controller was selected to be a Sliding mode control (SMC) and to accurately simulated the environment of KNATTE the continuous control signal would need to be converted to a pulse due to the thrusters on KNATTE either being on or off. The thesis found that the Pulse-width pulse-frequency (PWPF) modulation is necessary for both controllers to have the best performance as the Pulse-width modulation (PWM) is not able to generate a thrust output that gives a desired result. It is also found that the SMC will provide the shortest settling time for the attitude manoeuvre while also displacing the panels the least amount compared to that of the LQG controller.

Cement has a large climate footprint through the release of carbon dioxide in the manufacturing process. Rheometers, that measure the flow resistance in concrete, are available on the market today. They have very high accuracy but are also complex and expensive. There is a need for a simpler and cheaper measurement tool that complements existing, manual methods. Against this background, two research questions were created: • RQ1: How can a measuring paddle be rotated and the flow resistance be measured in a cost-effective way? • RQ2 - How can one build a machine without too expensive components with results similar to commercial rheometers? A prototype for measuring device, measuring electrical power, was designed and built based on the above research questions. The prototype was evaluated with two different liquids with known viscosity and two different concrete mixtures with different types of sand. The result is positive and shows a relation between flow resistance and used electrical power. However, additional tests and also calibration are needed.

La resolución temporal es uno de los principales factores que limitan el rendimiento de los sistemas digitales. Debido a ello, la incorporación de módulos que poseen alta resolución en el dominio del tiempo dentro de estructuras estándar ha despertado gran interés en los últimos años. Estos bloques pueden ser usados para mejorar la codificación de las señales binarias (al aumentar los niveles de cuantización) o reducir la distorsión en determinadas modulaciones digitales, entre otras aplicaciones. En esta tesis se aborda la temática desde distintos enfoques. Dos circuitos integrados fueron fabricados para evaluar un novedoso esquema circuital, el cual permite obtener un retardo temporal programable en el orden de los picosegundos, ajustable en un cierto rango para brindar mayor versatilidad ante distintas condiciones de operación. Su control y calibración se realizan mediante palabras binarias, lo que permite su integración en sistemas más complejos totalmente digitales. Ambos circuitos integrados fueron utilizados en distintas variantes de moduladores por ancho de pulso, alcanzando un desempeño superior al de las arquitecturas convencionales debido a la mayor precisión en el posicionamiento de los flancos de las señales. Asimismo, se presenta una nueva técnica de modulación apta para la implementación de un transmisor de radiofrecuencia totalmente digital. La arquitectura propuesta presenta un desempeño comparable con otras técnicas usadas en la actualidad, demostrado con un análisis completo que incluye simulaciones y resultados experimentales. En este caso las implementaciones se realizaron sobre dispositivos de lógica programable. / Time resolution is one of the main factors limiting the performance of digital systems. Due to this, the addition of modules that have high resolution in the time domain within standard structures has awakened great interest in recent years. These blocks can be used to improve the coding of binary signals (by increasing quantization levels) or to reduce distortion in some digital modulations, among other applications. In this thesis, the subject is addressed from different approaches. Two integrated circuits were manufactured to evaluate a novel circuit diagram, which allows obtaining a programmable time delay in the order of picoseconds, adjustable in a given range to provide greater versatility under different operating conditions. Its control and calibration are done using binary words, which allows its integration in more complex fully-digital systems. Both integrated circuits were used in different variants of pulse width modulators, achieving a better performance than conventional architectures due to the greater precision in the positioning of the signal edges. Likewise, a new modulation technique suitable for the implementation of a fully digital radio frequency transmitter is presented. The proposed architecture displays a performance comparable to other techniques used nowadays, demonstrated with a complete analysis that includes simulations and experimental results. In this case, implementations were carried out on programmable logic devices.