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Influence of temperature on light-technical parameters of LED
Sláma, Pavel ; Štěpánek, Jaroslav (referee) ; Pavelka, Tomáš (advisor)
This thesis deals with LEDs and how temperature influences their parameters. In the first part it is analyzed how semiconductors and semiconductor junctions work, which is fundamental for understanding mechanisms of diodes. Next up is description of electroluminescence and basic description of physical principles, on which it works. Following part is supposed to introduce reader to electro-technical parameters and powering possibilities of LEDs. Following chapter focuses on description of lightning-technical parameters. It aims to describe their meaning and their relation to LEDs. Next part is about influence of temperature. Firstly, it names the parameters which are altered by temperature change. Follows the description of thermal management and its influence on right behavior of LED diodes. The last part contains construction of measuring workplace for analyzing temperature influence on lightning-technical parameters of LEDs. Measurement of chosen electrical and lightning parameters follows up.
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Perspective materials for packaging
Gančev, Jan ; Psota, Boleslav (referee) ; Szendiuch, Ivan (advisor)
The first part of work deals with the theory of packaging of semiconductor chips and hybrid integrated circuits and defining material properties essential to the packaging. In the second, experimental part are defined the basic principles of heat transfer and heat dissipation of created package using thermocouple, thermal camera and static-thermal simulation. In the last part there is created design recommendations for package based on the comparison of the results.
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Optimalization of power supply for LED light sources
Koždoň, Jakub ; Kosina, Petr (referee) ; Boušek, Jaroslav (advisor)
This work focuses on description of function, analysis of degradation process, measuring lifetime and design thermal and electrical driving circuit for LED. Lifetime power LED basically depends on their working temperature. So some methods for measuring and determine LED lifespan and impacts which affects their lifetime are going to be described. Driving circuits are one of keys of element lamps. Their characteristics can affect lifetime of all lamp. So some properties and impacts of circuits for driving LED's and their functions which are necessary need to know in design will be described . I'll also catalogue some circuits which are suitable for that and show particular design power supply for LEDs and it's realization.
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Simulation of heat dissipation for power component
Sedlář, Tomáš ; Macháň, Ladislav (referee) ; Čožík, Ondřej (advisor)
The diploma thesis deals with the simulation of heat dissipation for LED Seoul SZ5-P. The heat transfer is discussed first. Further, the issue of thermal management and its design is analyzed. The dependence of LED junction temperature on area of single and double layer printed circuit board is simulated with Ansys Icepak. Additionally, influences of the number and placement of vias on the printed circuit board and aluminum substrate printed circuit board are simulated. Last but not least, the equations describing the dependence of printed circuit board area on desired LED junction temperature are derived. Finally, the values of heat transfer coefficient including convection and radiation are determined for various heat losses and junction temperatures.
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Emisivity and its Impact on the Heat Conductivity
Gančev, Jan ; Hejátková, Edita (referee) ; Szendiuch, Ivan (advisor)
This work deals with the issue of emissivity and its impact on the heat dissipation.The first part describes the basics of thermal management, the issue of emissivity and its measurement. In the second, experimental part, are dedicated the emissivity values of examined specimens. These values are then used as initial conditions for the thermal simulation. In the last part are compared the measured results and the simulated results and is evaluated the impact of emissivity for the heat dissipation.
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Development and design of a modular battery box.
Rozinek, Josef ; Buday, Vladimír (referee) ; Porteš, Petr (advisor)
Tato práce se zabývá problematikou battery packů. V první části popisuje návrh battery packu z hlediska volby baterií, jejich tvaru, velikosti, typu a konfigurace zapojení. Dále uvádí vliv těchto charakteristik na výkonnost battery packu a jeho spolehlivost. Zabývá se problematikou termálního managementu battery packů a jeho vlivu na životní cyklus baterií. V druhé části se zabývá praktickým návrhem konceptu battery packu pro Lithium-polymerové baterie. Kalorimetricky je zde zjištěno množství produkovaného tepla při vybíjení, které je poté využito v CFD simulaci chlazení článku.
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Optimization of the printed circuit board for power LED
Schenk, David ; Klíma, Martin (referee) ; Ing. Josef Vochyán, Ph.D., ALCZ Jihlava (advisor)
This diploma thesis deals with the problems of heat transfer on printed circuit boards. The first part consists of a theoretical analysis of the principles of conduction of heat in different environments, comparing the properties of common type’s base materials for PCBs in terms of thermal properties and focuses on heat transfer from the chip. In the following part they are general information about the program ANSYS ® Workbench ™. Next part consists of the basic designs of PCBs and their improving. PCBs thermal properties for different configurations are verified with calculations, simulations and practical measurements. In the last part there are created design recommendations for PCBs design based on the comparison of the results of initial proposals and proposals to improvements.
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Development in 3D Packaging for Modern Electronics Systems
Prikryl, Petr ; Švecová, Olga (referee) ; Szendiuch, Ivan (advisor)
The aim of this diploma thesis is 3D package design study and elaboration of rules for effective thermal and electrical design. There are recommendations and equations for calculating parameters affecting design of modern SOP and SIP packages mentioned in this thesis. Advantages of modern technologies in thermal management of packages are demonstrated in the second part of thesis using ANSYS workbench.
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Lighting systems of vehicle
Žlebek, Michal ; Guzej, Michal (referee) ; Štětina, Josef (advisor)
The aim of this work is to explore the development of headlamps and focus on the problem of cooling. The first part is devoted to automotive lighting and to headlamps generally. It deals with history, manufactures, functions and basic construction of headlamps. The next section describes the types of headlamp and the procedure for its construction depending on used light source. In semifinal part can be found explanation of heat origin in LED and with the help of heat transfer is described its spreading. At the end is this work dealing with problems of cooling when using LEDs. It shows view of cooler and explaining how important is to use simulations during heat spreading counting.
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Modern Trends in Vehicle Front Lights Design
Rada, Jakub ; Maršálek, Ondřej (referee) ; Raffai, Peter (advisor)
This bachelor’s thesis deals with the modern trends in the design of the headlamps. The first part presents the sequential stages of development of systems used for headlamps and their design solutions. The second part focuses on the possible cooling alternatives of functional parts in lighting modules, completed with the results of comparative laboratory tests performed by front manufacturers of automotive lighting. The final section contains a comparison of the currently most widely used technologies in the vehicle front lighting.
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