This project explores the rapidly expanding area of AC direct drive for LED lighting. AC LED driving does not use typical DC-DC converter-based driving but uses semiconductor switches and a linear regulator to activate a number of LEDs proportional to the input voltage at any given time. This allows bulky, expensive magnetics to be eliminated from the system. The goal of this project was to design a scaled-down physical AC LED direct drive system to validate the conclusions of methods for improving efficiency from a previous investigation that found minimizing voltage across the linear regulating MOSFET led to higher efficiency at the cost of increased input current THD. This project found that this conclusion is physically realizable, with a final efficiency of 94.46% and an input current THD of 58.9%. This result was achieved by taking the previous investigation’s final design as a starting point and replacing ideal switches and control signals with discrete components. The final version uses a set of comparators and sense resistors to determine when a given LED stack should be on for a simple, analog control solution. Once the system was simulated this way, the assembled version was used to measure efficiency, power factor, current THD, flicker index, and DC supply power. Additional plots of the stack voltages and control signals were collected to verify proper operation and compare to simulation. The final measurements aligned with trends from simulation and result in a simple AC direct drive solution that requires no specialty ICs.

The main goal of this diploma thesis is to compare two circuits designed for LED powering with output current of units of Amperes. Both circuits are based on step-down converter topology, one with technology of synchronous rectifying and the other one without it. Calculations and selection of used components with real prototypes were made for both selected circuits. All selected components meet automotive qualification requirements for discrete products. Produced prototypes were compared in terms of functionality, efficiency, EMC and thermal radiation.

The paper discusses a design of a matrix LED display for car rear combination lamps and its power supply. It provides basic information about converters, light, and electronics requirements in the automotive industry. The design of individual circuits, printed circuit board, and firmware are analyzed. Predefined animations have safety, practical, and design functions. The innovative solution presents a new level of communication between the vehicle and its environment. The purpose is to increase safety and improve traffic flow.

This master thesis is focused on designing a concept of a biodynamic tunable white luminaire for the interior capable of producing user defined output or simulating the conditions of natural exterior lighting. The thesis describes the physiological basis of human sensitivity to lighting and the consequences, as well as the principles of semiconductor radiation sources. Finally, it deals with methods of sensing the lighting conditions and describing the design and functions of the system elements and final implementation.

Progress in development of modern LEDs, their long lifetime and high luminous efficacy predetermine them for usage in lighting systems. This master's thesis examines possibilities of application of LEDs in luminaires, parameters of diodes and problems, which can appear in construction of luminaire with LED lighting source. In the practical part of this thesis a luminaire is designed, capable of illuminating traffic signs, vertical surfaces, billboards and fasades. By standards required parameters of a lighting system and adaptability of application must be considered in complex predesign. Simulations of lighting scene, created in special computer software, measurements of optical point’s parameters and construction of real luminaire model using high quality CREE LEDs, are included in analysis of the problem. Parameters of the luminaire were proved by measurements of product’s attributes at light laboratory. There are also some suggestions for improvement and further development of the product.

This diploma thesis deals with system for visible light communication (VLC). There are described basic optical elements like a electroluminescence diode and photodiode. In next chapter is described design of transmitter, optical channel and receiver. Attention is also devoted to modulation suitable for optical communication. The last chapter is devoted to program in Matlab language, which's name is Program for calculation of optical intensity distribution. That program was created in this diploma theses.

The aim of this master’s thesis was the design RGB LED display with Ethernet interface. I created a display module, controlled by a microcontroller ATmega 2560-16AU. These modules can be connected via a serial RS485 standard. Ethernet connection is made via plug-in interface that uses the programmable module Rabbit RCM 3200. I documented a proposal. I tested designed device.

This thesis deals with an electronic circuit and a PCB of a modular RGB LED display with the Ehernet interface. Firstly, author describes a RGB colour model, features of RGB LED displays, ways of control them. The next chapter contains a short description of the Ethernet interface, UDP and TCP protocols and a lwIP TCP/IP stack. The last theoretical chapter is an introduction to ARM Cortex-M3 and Cortex-M4 based microcontrollers. The next chaper is deals with a hardware design of the modular RGB LED display. The device is designed to be modular. Individual devices can be combosed together and create a larger display. Data from the Ethernet interface will be displayed on the RGB LED matrix, resolution of the matrix is 32 × 32 (1024 diodes). A refresh frequency is 100 Hz, a color depth is High color (16 bits) and a scanning 1/16 (two rows is driven at the same time). The next chapter describes the firmware for the RGB LED display, all its logical parts including a web page. Author also created the PC application, which sends pictures using UDP protocol to individual modules.

This master thesis is a design study of LED interior light units. Aim of the study is to design set of three luminaire types – office table light, standard lamp and a pendant luminaire. All three lights are following the same design. Curve is the main shape for this light set. LED, called light source of the future, is supposed to be the only light source at all three units. LEDs were chosen as the contemporary most efficient and modern light source. Use of LEDs has many positive economical and social aspects. Use of innovative design, most recent technologies and modern shapes brings new inspiration and variety into current interior light world. Development of light systems study is mapping light units history from the beginning into presence. It brings interesting look into interior light history.

This work deals with modernization of information LED panels. It mainly focuses on utilizing input HDMI interface into FPGA, which controls modular LED displays, but also on ensuring professional functions such as communication with control unit, thermal security and detection of faulty LED.