Journal ArticleDOI
A General Photo-Electro-Thermal Theory for Light Emitting Diode (LED) Systems
Shu Yuen Ron Hui,Y.X. Qin +1 more
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TLDR
In this article, a general theory that links the photometric, electrical, and thermal behaviors of an LED system together is presented, which can be used to determine the optimal operating point for an LED systems so that the maximum luminous flux can be achieved for a given thermal design.Abstract:
The photometric, electrical, and thermal features of LED systems are highly dependent on one another. By considering all these factors together, it is possible to optimize the design of LED systems. This paper presents a general theory that links the photometric, electrical, and thermal behaviors of an LED system together. The theory shows that the thermal design is an indispensable part of the electrical circuit design and will strongly influence the peak luminous output of LED systems. It can be used to explain why the optimal operating power, at which maximum luminous flux is generated, may not occur at the rated power of the LEDs. This theory can be used to determine the optimal operating point for an LED system so that the maximum luminous flux can be achieved for a given thermal design. The general theory has been verified favorably by experiments using high-brightness LEDs.read more
Citations
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Journal ArticleDOI
A High-Efficiency Dimmable LED Driver for Low-Power Lighting Applications
TL;DR: A dimmable light-emitting diode (LED) driver with adaptive feedback control for low-power lighting applications and an improved pulsewidth modulation dimming technique is studied for regulating the LED current and brightness.
Journal ArticleDOI
Analysis and Design of the Integrated Double Buck–Boost Converter as a High-Power-Factor Driver for Power-LED Lamps
TL;DR: It is demonstrated that, with a careful design of the converter, the filter capacitances can be made small enough so that film capacitors may be used, and the converter mean time between failures can bemade as high as that of the solid-state lamp.
Thermal management of LEDs: Package to system
TL;DR: In this paper, the effect of chip packages on junction to board thermal resistance was compared for both SiC and Sapphire chips, and a conceptual LED illumination system was chosen and CFD models were created to determine the availability and limitations of passive air-cooling.
Journal ArticleDOI
A Survey, Classification, and Critical Review of Light-Emitting Diode Drivers
TL;DR: Based on a survey on over 1400 commercial LED drivers and a literature review, a range of LED driver topologies are classified according to their applications, power ratings, performance and their energy storage and regulatory requirements as discussed by the authors.
Journal ArticleDOI
A Novel Passive Offline LED Driver With Long Lifetime
TL;DR: In this article, the authors describe a patent-pending passive offline light-emitting diode (LED) driver that has no controlled semiconductor switches, electrolytic capacitors, auxiliary power supply, and control board.
References
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MonographDOI
Light-Emitting Diodes by E. Fred Schubert
TL;DR: In this paper, the authors present an overview of the history of light emitting diode (LED) and LED-based display technologies and apply them to a wide range of applications.
Proceedings ArticleDOI
Thermal management of LEDs: package to system
TL;DR: In this paper, the effect of chip packages on junction to board thermal resistance was compared for both SiC and Sapphire chips, and a conceptual LED illumination system was chosen and CFD models were created to determine the availability and limitations of passive air-cooling.
Thermal management of LEDs: Package to system
TL;DR: In this paper, the effect of chip packages on junction to board thermal resistance was compared for both SiC and Sapphire chips, and a conceptual LED illumination system was chosen and CFD models were created to determine the availability and limitations of passive air-cooling.
Journal ArticleDOI
Accelerated Life Test of High Brightness Light Emitting Diodes
Lorenzo Roberto Trevisanello,Matteo Meneghini,Giovanna Mura,Massimo Vanzi,Maura Pavesi,Gaudenzio Meneghesso,Enrico Zanoni +6 more
TL;DR: In this article, the degradation in light efficiency induced by thermal storage was found to follow an exponential law, and the activation energy of the process was extrapolated, implying that the degradation process of dc current aged devices is thermal activated due to high temperatures reached by the junction during stress.