Power Supplies for LED Driving


Book Description

Power Supplies for LED Driving, Second Edition explores the wide use of light-emitting diodes due to their efficient use of power. The applications for power LEDs include traffic lights, street lamps, automotive lighting, architectural lights, theatre lighting, household light replacements, signage lighting (replacing neon strip lights and fluorescent tubes), LCD display backlighting, and many more. Powering (driving) these LED's is not always simple. Linear driving is inefficient and generates far too much heat. With a switching supply, the main issues are EMI, efficiency, and of course cost. This book covers the design trade-offs involved in LED driving applications, from low-power, to UB-LEDs and beyond. - Provides a practical, hands-on approach to power supply design for LED drivers - Contains detailed examples of what works throughout the design process - Presents commentary on how the calculated component value compares with the actual value used, including a description of why the choice was made




Led Lighting and Drivers


Book Description

The book is organized in four chapters. Chapter 1 deals with an introduction to light and lighting. As a power electronics engineer working on LEDs and lighting systems in general, I think it is important for the reader to have the basic knowledge about lighting systems, which I have tried to summarize in this chapter. Because of the extremely interesting possibilities of LEDs to generate different light colors, Chapter 1 includes a section related to the understanding of color quantification and measurement in different color spaces. The Chapter also includes several examples on light and color calculations.In order to develop and implement a suitable LED driver, it is necessary to have a good knowledge about LED behavior and characteristics. Thus, Chapter 2 aims at providing the reader with the most important issues related to LED operation and modeling from a practical point of view. The most common LED structures and materials are presented in this chapter together with the most relevant electrical, thermal and optical characteristics, making special emphasis on those characteristics provided by LED manufacturers in their datasheets. Special sections are dedicated to light dimming and color mixing. The chapter is closed with a brief review of organic LED (OLED) technology, which is another promising LED technology nowadays.Chapter 3 is devoted to DC LED drivers, which are those LED drivers intended to supply the LED from a DC voltage source, like a battery or a DC bus. This chapter covers the three most relevant technologies that are being used to implement DC LED drivers at the present time, which are those based on linear regulators, switched capacitor regulators and switching regulators. The most relevant solutions to implement DC LED drivers are reviewed from a practical point of view. The chapter also reviews the most common control methods applied to DC LED drivers. Examples are included by means of computer simulations based on LTspice, which is a free but powerful SPICE-based simulation software developed by former Linear Technologies Company, now part of Analog Devices. The chapter ends with a section devoted to LED configurations, namely, series, parallel and matrix configurations, which are employed to implement high-power LED lamps.Finally, Chapter 4 is dedicated to off-line LED drivers. This is the denomination given to LED drivers that are intended to operate from an AC grid voltage. These are the most complicated LED drivers since they usually require the implementation of a front-end power-factor-correction (PFC) stage followed by a downstream DC-DC converter to adapt voltage levels and provide regulated current to the LED lamp. The most important standards and regulations related to this type of LED drivers are presented at the beginning of the chapter. Then, single-stage LED drivers are studied, which can be used as a stand-alone off-line LED driver or as a first stage in a two-stage off-line LED driver. The highly-relevant problem of requiring a large storage capacitance in single-stage off-line LED drivers to cope with the double-line-frequency pulsating power originated from line voltage rectification is addressed in this chapter. Finally, integrated two-stage off-line LED drivers are presented and studied as a solution to reduce the storage capacitance of off-line LED drivers, aiming at using high-reliability film-capacitors instead of less reliable electrolytic capacitors. LTspice simulation examples are also provided in this chapter to allow the reader to have a better idea about the design and operation of this type of LED drivers.




LED Lighting


Book Description

We’re on the brink of a lighting revolution with light-emitting diodes—the tiny LEDs you’ve seen in electronic devices for years. With this practical guide, you’ll go behind the scenes to see how and why manufacturers are now designing LED devices to light everything from homes and offices to streets and warehouses. Author Sal Cangeloso shows you the working parts of a “simple” LED bulb and explains the challenges electronics companies face as they push LED lighting into the mainstream. You’ll learn how you can use LEDs now, and why solid state lighting will bring dramatic changes in the near future. Explore the drivers, phosphors, and integrated circuits in a typical LED bulb Understand the challenges in producing LED bulbs with acceptable brightness, color temperature, and power consumption Learn about non-bulb LED applications, including lamps, street lights, and signage Discover the market forces driving—and impeding—the adoption of LED lighting Compare LEDs to compact fluorescent lamps (CFLs) and electron-stimulated luminescence (ESL) bulbs Gaze into the future of intelligent lighting, including networked lighting systems




LED Lighting


Book Description

Promoting the design, application and evaluation of visually and electrically effective LED light sources and luminaires for general indoor lighting as well as outdoor and vehicle lighting, this book combines the knowledge of LED lighting technology with human perceptual aspects for lighting scientists and engineers. After an introduction to the human visual system and current radiometry, photometry and color science, the basics of LED chip and phosphor technology are described followed by specific issues of LED radiometry and the optical, thermal and electric modeling of LEDs. This is supplemented by the relevant practical issues of pulsed LEDs, remote phosphor LEDs and the aging of LED light sources. Relevant human visual aspects closely related to LED technology are described in detail for the photopic and the mesopic range of vision, including color rendering, binning, whiteness, Circadian issues, as well as flicker perception, brightness, visual performance, conspicuity and disability glare. The topic of LED luminaires is discussed in a separate chapter, including retrofit LED lamps, LED-based road and street luminaires and LED luminaires for museum and school lighting. Specific sections are devoted to the modularity of LED luminaires, their aging and the planning and evaluation methods of new LED installations. The whole is rounded off by a summary and a look towards future developments.




Analog Circuit Design Volume Three


Book Description

Design Note Collection, the third book in the Analog Circuit Design series, is a comprehensive volume of applied circuit design solutions, providing elegant and practical design techniques. Design Notes in this volume are focused circuit explanations, easily applied in your own designs. This book includes an extensive power management section, covering switching regulator design, linear regulator design, microprocessor power design, battery management, powering LED lighting, automotive and industrial power design. Other sections span a range of analog design topics, including data conversion, data acquisition, communications interface design, operational amplifier design techniques, filter design, and wireless, RF, communications and network design. Whatever your application -industrial, medical, security, embedded systems, instrumentation, automotive, communications infrastructure, satellite and radar, computers or networking; this book will provide practical design techniques, developed by experts for tackling the challenges of power management, data conversion, signal conditioning and wireless/RF analog circuit design. - A rich collection of applied analog circuit design solutions for use in your own designs. - Each Design Note is presented in a concise, two-page format, making it easy to read and assimilate. - Contributions from the leading lights in analog design, including Bob Dobkin, Jim Williams, George Erdi and Carl Nelson, among others. - Extensive sections covering power management, data conversion, signal conditioning, and wireless/RF.




Designing with Light


Book Description

The new edition of the popular introduction to architectural lighting design, covering all stages of the lighting design process Designing with Light: The Art, Science, and Practice of Architectural Lighting Design, Second Edition, provides students and professionals alike with comprehensive understanding of the use of lighting to define and enhance a space. This accessible, highly practical textbook covers topics such as the art and science of color, color rendering and appearance, lighting control systems, building codes and standards, and sustainability and energy conservation. Throughout the text, accomplished lighting designer and instructor Jason Livingston offers expert insights on the use of color, the interaction between light and materials, the relation between light, vision, and psychology, and more. Fully revised and updated throughout, the second edition features new chapters on design thinking, common lighting techniques, and lighting economics. Expanded sections on aesthetics, controlling LEDs, light, and health, designing with light, and color mixing luminaires are supported by new case studies, examples, and exercises. Featuring hundreds of high-quality color images and illustrations, Designing with Light: Provides systematic guidance on all aspects of the lighting design process Thoroughly covers color and light, including color perception, color rendering, and designing with colored light Explains the theory behind the practice of architectural lighting design Contains information on cost estimating, life cycle analysis, voluntary energy programs, and professional lighting design credentials Includes an instructor resource site with PowerPoint presentations, test questions, and suggested assignments for each chapter, and also a student site with flashcards, self-evaluation tests, and helpful calculators. Designing with Light: The Art, Science, and Practice of Architectural Lighting Design, Second Edition is perfect for architecture, interior design, and electrical engineering programs that include courses on lighting design, as well as professionals looking for a thorough and up-to-date desk reference.




Lighting for Driving


Book Description

By considering vehicle, signal, and road lighting as integrated means of communication, this unique authoritative work explains the thinking and scientific reasoning behind various forms of lighting and analyzes their contribution to the driver's understanding of real and potential road hazards. Attention is also given to how these forms of lighting are likely to evolve in response to the development of new technology and an improved understanding of ergonomics.




Assessment of Solid-State Lighting, Phase Two


Book Description

The standard incandescent light bulb, which still works mainly as Thomas Edison invented it, converts more than 90% of the consumed electricity into heat. Given the availability of newer lighting technologies that convert a greater percentage of electricity into useful light, there is potential to decrease the amount of energy used for lighting in both commercial and residential applications. Although technologies such as compact fluorescent lamps (CFLs) have emerged in the past few decades and will help achieve the goal of increased energy efficiency, solid-state lighting (SSL) stands to play a large role in dramatically decreasing U.S. energy consumption for lighting. Since the publication of the 2013 National Research Council report Assessment of Advanced Solid-State Lighting, the penetration of SSL has increased dramatically, with a resulting savings in energy and costs that were foreshadowed by that study. What was not anticipated then is the dramatic dislocation and restructuring of the SSL marketplace, as cost reductions for light-emitting diode (LED) components reduced profitability for LED manufacturers. At the same time, there has been the emergence of new applications for SSL, which have the potential to create new markets and commercial opportunities for the SSL industry. Assessment of Solid-State Lighting, Phase Two discusses these aspects of changeâ€"highlighting the progress of commercialization and acceptance of SSL and reviewing the technical advances and challenges in achieving higher efficacy for LEDs and organic light-emitting diodes. This report will also discuss the recent trends in SSL manufacturing and opportunities for new applications and describe the role played by the Department of Energy (DOE) Lighting Program in the development of SSL.




Introduction to Light Emitting Diode Technology and Applications


Book Description

Recent improvements in LED technology have made them as ubiquitous as cell phones. In fact, LEDs light up almost all cell phones screens. The technology's myriad applications and low energy use have made it nearly impossible to get through daily chores without coming in contact with LEDs. Probable advances include increased ability of the technology to support more efficient lighting and enhanced communications. With balanced coverage of the basics and future developments, Introduction to Light Emitting Diode Technology and Applications takes you on a tour of the LED evolution. The book begins with a brief history of the effort to enable the device that generates light through modern organic LEDs and reviews the fundamentals and principles of light prior to a detailed explanation of how LEDs generate different colors. After forming this basic foundation, the book examines the key LEDs in lighting and communications. It then discusses the latest opportunities and advancements in high brightness (HB) LED technology, solid state lighting, and handheld electronic applications. As we approach a new decade the role of LEDs is literally set to explode, with organic light emitting diodes emerging as a leading next generation technology for electronic displays and lighting. Challenges still exist, including light extraction, luminosity, and white light generation, not to mention non-technical obstacles such as IP disputes and the lack of standards. This book provides a foundation for resolving these issues and developing new applications for LEDs in the promising general illumination market.




LED Roadway Lighting


Book Description

Light emitting diode (LED) technology has revolutionized the lighting industry. The dimming and instant-on capabilities of these light sources along with their high efficiency have allowed lighting designers to overcome some of the limitations of previous technologies, particularly in roadway lighting environments. However, concerns related to the health and environmental impacts of LEDs have been raised. The TRB National Cooperative Highway Research Program's NCHRP Research Report 968: LED Roadway Lighting: Impact on Driver Sleep Health and Alertness seeks to determine the impact of LED roadway lighting on driver sleep health and alertness.