Teses / dissertações sobre o tema "Strong Lead"
Crie uma referência precisa em APA, MLA, Chicago, Harvard, e outros estilos
Veja os 34 melhores trabalhos (teses / dissertações) para estudos sobre o assunto "Strong Lead".
Ao lado de cada fonte na lista de referências, há um botão "Adicionar à bibliografia". Clique e geraremos automaticamente a citação bibliográfica do trabalho escolhido no estilo de citação de que você precisa: APA, MLA, Harvard, Chicago, Vancouver, etc.
Você também pode baixar o texto completo da publicação científica em formato .pdf e ler o resumo do trabalho online se estiver presente nos metadados.
Veja as teses / dissertações das mais diversas áreas científicas e compile uma bibliografia correta.
Hluchan, Sarah Kathleen. "Smart growth for strong communities which existing smart growth features lead to highly desirable neighborhoods? /". Connect to Electronic Thesis (CONTENTdm), 2009. http://worldcat.org/oclc/444620211/viewonline.
Texto completo da fonteD'Amico, Samantha. "HMHS Royal Comfort". Digital Commons at Loyola Marymount University and Loyola Law School, 2021. https://digitalcommons.lmu.edu/etd/979.
Texto completo da fonteBlad, Eleonor, e Lykke Paulsson. "Lean implementering ur ett medarbetarperspektiv : En kvalitativ fallstudie om faktorer som påverkar medarbetares arbetsmiljö vid implementering av lean". Thesis, Högskolan i Gävle, Avdelningen för ekonomi, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-36404.
Texto completo da fonteAim: The aim of the study is to create understanding of the implications of lean implementation on the work environment seen from the coworker perspective Method: Qualitative case study with primary data collected by interviews of managers and employees at ICA Maxi Special in two different cities. Secondary data was collected from scientific articles and relevant literature regarding previous research in the field. Result & Conclusions: The study reveals that implementation of lean affects the coworkers' perceived work environment and that factors such as participation, meaningfulness, autonomy, communication and education are important factors for a good work environment. The initial reluctance experienced by coworkers when implementing the concept was later exchanged for a positive attitude and a new way of work, which consequently led to a better working environment in general. Contribution of the thesis: The findings of this study contribute to research by understanding and highlighting the factors that influence the employees work environment. By understanding the effect of external structures, such as lean and how it affects internal structures, and such as the actions and reactions of coworkers, companies can mitigate the impact on the work environment when implementing lean. Suggestions for future research: The study is rather small and conducted at a workplace where most of the employees have worked together for several years. Therefore, we suggest that future studies can be conducted at companies with a larger employee turnover, or at a different type of company in the service industry, or as a comparative study between
Claeson, Mikael. "Mixing strings of Lithium-Ion and Lead-Acid in parallel". Thesis, Mittuniversitetet, Institutionen för elektronikkonstruktion, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-39400.
Texto completo da fonteAvsikten med detta exjobb har varit att testa och analysera beteendet av batteri-system där man blandar litium och bly parallellt. Den underliggande teorin om varför batterier av olika kemier beter sig på ett visst sätt tillsammans undersöktes för att få en förståelse för testresultaten. Ett flertal tester gjordes med olika batterier, laster och laddare för att verifiera teorin och för att upptäcka fall där systemet funkar bra och där det funkar dåligt. Baserat på denna förståelse gjordes ett script med avsikten att hitta en punkt med en lägsta årlig kostnad. Denna kostnad jämfördes sedan med system bestående av enbart bly samt enbart litium. Det slutgiltiga målet med scriptet var att en säljare ska kunna fylla i kända parametrar för en viss telekom-anläggning. Scriptet lägger sedan till ett litet Litium-batteri parallellt med ett konstant bly-batteri. För att sedan öka på Litium i storlek och uppskatta urladdningsdjupet för Litium och bly vid varje steg, tills dess att Li har samma storlek som bly. En punkt för minsta kostnaden presenteras sedan tillsammans med optimal storlek av Litium samt rekommenderade max-strömmar.
Gilliom, Michael B. "Use of SIMO Converstion for Optimizing LED Light Drivers". Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/76876.
Texto completo da fonteMaster of Science
Antonakakis, Nikolaos, Mina Dragouni e George Filis. "How Strong is the Linkage between Tourism and Economic Growth in Europe?" Elsevier, 2015. http://dx.doi.org/10.1016/j.econmod.2014.10.018.
Texto completo da fonteBarton, Robert Allan. "Multi-strange hyperon production in relativistic heavy -ion collisions". Thesis, University of Birmingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367744.
Texto completo da fonteVillalva, Nicholas E. "Design, construction and analysis of an LED strobe controller". Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/85515.
Texto completo da fonteCataloged from PDF version of thesis.
Includes bibliographical references (page 51).
In this thesis, I describe an LED strobe controller that I designed and built. With the advent of much brighter LEDs, it is possible to create stroboscopes with both high intensity output and high maximum flash rates. Additionally, the proliferation of Wi-Fi enabled devices provokes the idea of a next-generation interface for tools in Strobe Lab. The initial goal was to produce an LED-based strobe that has sufficient light to replace existing flash tube stroboscopes. The final product combines three high powered LEDs with a microcontroller and Wi-Fi card. Users can adjust settings through a web based interface accessible from both laptops and mobile devices. In addition to the simple user interface, the controller is compatible with other equipment in Strobe Lab as it can be triggered by the commonly used methods. Established techniques, such as sync and delay, and newer techniques, such as color-encoded multi-flash images, are possible with this device.
by Nicholas E. Villalva.
M. Eng.
Sperry, Robert George. "DEVELOPMENT OF A SEMI-AUTOMATED TOBACCO STRIPPING MACHINE UTILIZING STRING TRIMMERS". UKnowledge, 2011. http://uknowledge.uky.edu/gradschool_theses/89.
Texto completo da fontePickering, Mary Theresa. "Rb Inactivation Leads to E2F1-mediated DNA Double Strand Break Accumulation: A Dissertation". eScholarship@UMMS, 2006. https://escholarship.umassmed.edu/gsbs_diss/26.
Texto completo da fonteStrong, Austin Michael. "Lean Six Sigma's Impact on Firm Innovation Performance". BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/6877.
Texto completo da fonteSWAMINATHAN, MOHAN. "CONTRIBUTIONS TO ENHANCE PRACTICAL IMPLEMENTATION OF LEAN MANUFACTURING IN INDUSTRIAL ENVIRONMENTS". UKnowledge, 2004. http://uknowledge.uky.edu/gradschool_theses/368.
Texto completo da fonteXie, Hong. "Misrepair of Particulate Chromium(VI)-Induced DNA Double Strand Breaks Leads to Neoplastic Transformation". Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/XieH2007.pdf.
Texto completo da fonteBentley, Danielle Sarah. "Restrung new chamber festival : an exploration of contemporary string practice". Thesis, Queensland University of Technology, 2011. https://eprints.qut.edu.au/49582/1/Danielle_Bentley_Thesis.pdf.
Texto completo da fonteHamon, Julien. "Etude de la production des mésons charmés-étranges dans les collisions proton-proton et proton-plomb avec l'expérience ALICE au LHC". Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAE012/document.
Texto completo da fonteThe study of the production of charm quarks in high-energy atomic-nucleus collisions offers an genuine approach for the study of the quark-gluon plasma. The understanding and characterisation of this state of deconfined-matter, at first sight created in heaviest systems, require a fine knowledge of lightest systems, such as proton-proton (pp) and proton-lead (p-Pb) collisions. In this manuscript, we present the measurement of the charm-strange mesons Ds+ production, at central rapidity, with the LHC run 2 data, collected in 2016 with the ALICE experiment. Two systems are studied: pp collisions at √s=13 TeV and p-Pb collisions at √sNN=5.02 TeV. The production cross-section of Ds+, their relative abundance and their nuclear modification factor are measured then compared to other measurements and to various theoretical predictions. The p-Pb result establishes a new reference for the study of Pb-Pb collisions
Moussa, Angela. "Altering the level of lamin B1 leads to double-strand break repair defects and replicative stress". Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS011.
Texto completo da fonteThe overexpression of lamin B1, a major component of nuclear envelope, has been reported in various tumors. However, the causes and consequences of this increase on the genome stability have not been studied to date. Indeed, genome instability is considered a major hallmark of cancer cells. To ensure the maintenance of genome stability, cells have developed multiple complex mechanisms among which pathways of DNA repair and replication stress management are essential. Therefore, during my thesis the impact of an increased lamin B1 level on genome stability, in particular on double-strand break (DSB) repair and on the control of replication stress was studied. Indeed, we show that increased lamin B1 leads to an accumulation of DSBs and their persistence in response to irradiation (γH2AX foci), in addition to an increased sensitivity to irradiation (colony formation and chromosomal breaks). Lamin B1 overexpressing cells also show defects in the recruitment of 53BP1 to damage sites, coupled to a decreased efficiency of DSB repair by Non-Homologous End-Joining. Moreover, we identified a direct interaction between lamin B1 and 53BP1 regulating the latter’s recruitment to DSBs. Our results support a model where increased lamin B1 leads to the sequestration of 53BP1, thereby altering its recruitment to DSBs. In parallel, we show that cells overexpressing lamin B1 display increased signs of replication stress such as accumulation of spontaneous p-RPA foci, increased radial chromosomes upon mitomycin C treatment, and enhanced sensitivity to treatment with camptothecin. We further aimed to identify the causes of the increased replication stress in these cells, in addition to the potential consequences, in particular on the induction of inflammatory phenotypes. In fact, we show that lamin B1 overexpression leads to a decreased efficiency of DSB repair by Homologous Recombination, coupled to a defect in irradiation-induced BRCA1 foci formation. In addition, we obtained preliminary data suggesting a possible induction of inflammation upon lamin B1 overexpression. Altogether, this work identifies a novel mechanism regulating the recruitment of 53BP1 to damage sites through its interaction with lamin B1, and highlights the role of increased lamin B1 in promoting genome instability at least partially through defective DSB repair and increased replication stress. Upon confirming the induction of inflammatory phenotypes, we would have identified roles of increased lamin B1 in promoting two major hallmarks of cancer – genomic instability and inflammation - thereby favorizing a role for lamin B1 in tumor development and proposing the latter as a potential anti-tumor therapeutic target
Velehradský, Petr. "KVANTIFIKACE PŘESNOSTI MĚŘENÍ TLAKOVÝCH ZTRÁT PŘI HODNOCENÍ PÓROVITOSTI HLINÍKOVÝCH ODLITKŮ". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-228020.
Texto completo da fonteMaikowski, Lea Friederike [Verfasser], e Karin [Akademischer Betreuer] Meißner. "Neuronal and behavioural pain processing : a comparison between a strong brand and a generic medication placebo using the example of Aspirin vs. 1A Pharma / Lea Friederike Maikowski ; Betreuer: Karin Meißner". München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1153338416/34.
Texto completo da fonteSmeliková, Lenka. "Kontrola kvality pájeného spoje a Design of Experiments u strojního pájení vlnou". Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220991.
Texto completo da fonteBen, Chaabane Faten. "Couplage entre émetteurs organiques et antennes optiques : perspectives pour l'éclairage et la signalisation automobile". Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASP078.
Texto completo da fonteThis thesis is a first step to develop a novel class of coherent but non-lasing light sources in the visible range for automotive lighting and signaling applications. Several theoretical, numerical and experimental aspects have been addressed. Structures combining organic emitters and optical nanoantennas (NPs) have been fabricated to demonstrate, on the one hand, a luminescence enhancement due to the plasmonic resonances of the antennas, and, on the other hand, a signature of strong coupling. Our structures do not suffer from emission quenching despite the fact that the metallic NPs are in direct contact with the organic layer. These results are consistent with the local Kirchhoff law that applies when the molecules of theorganic layer are in the thermalization regime. A finite element model has been developed to study the coupling between an active dipolar medium and plasmonic nanoantennas in a Light Emitting Diode (LED) structure. This model makes it possible to include the nonlinear response of a two-level dipolar active medium in electromagnetic simulations in the frequency domain. Finally, a first OLED (Organic LED) device was also developed, as a preliminary and essential step towards an extended coherent source. A possible follow-up to this work will be to optimize the OLED and insert nanoantennas in its design, so as to transform the structure into a device emitting light in the strong coupling regime and in the presence of a collective state
Schaerström, Fredrik. "Icke-fysiska fiskledare : En laborationsstudie för att utvärdera tre fiskledare av bubblor och strobeljus och deras funktion i att leda laxsmolt vid nedströmsvandring". Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-140407.
Texto completo da fontePassages by fish through hydropower plants are associated with high mortality. In order to reduce the impact of hydropower plants on fish stocks, a variety of fish guiding systems have evolved. In this laboratory study, three types of non-physical fish guiding systems were evaluated by their efficiency in leading cultivated smolt of Atlantic salmon (Salmo salar L.) to a desired passage. This study aimed to answer if it is possible to guide salmon smolt to a desired safe passage by using bubbles, strobe light or a combination of bubbles and strobe light. With relatively simple means and low cost, fish-guides were constructed consisting of a perforated tube driven by an air compressor and a light ramp with four LED lights, which simultaneously flashed at 480 bpm. Five replicates were performed for each treatment; bubbles, strobe light and bubbles / strobe light, as well as six replicates for the controls. During one hour of treatment, ten salmon smolt, marked with PIT tag, could pass one of two antennas, where one had a fish-guide in front of the antenna, while migrating downstream in a stream aquarium. This study showed that fish-guides of all three methods led smolt to a desired passage during the first fifteen minutes of treatment. Furthermore, the bubble method showed a continuous guiding capacity throughout the treatment period (60 minutes), while the strobe light and bubble/strobe light did not show such an effect.
Bartl, Jan. "Příprava realizace multifunkčniho objektu Technologického parku v Brně". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409915.
Texto completo da fonteDvořák, Radim. "Zvýšení efektivity montážního pracoviště". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318827.
Texto completo da fonteHořínková, Dita. "Stavebně technologický projekt výstavby komplexu RD SLAVKOV - Pod Zlatou horou". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409928.
Texto completo da fontePrůcha, Aleš. "Příprava realizace dostavby klinické hematologie FN Brno". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409941.
Texto completo da fonteHoffmann, Stephen Reed. "Strong binding of copper, zinc, and lead to colloids and natural organic matter in rivers". 2002. http://www.library.wisc.edu/databases/connect/dissertations.html.
Texto completo da fonteMilkiewicz, Olga. "EasyJet Plc: lean, strong and determined". Master's thesis, 2015. http://hdl.handle.net/10362/15415.
Texto completo da fonteYeh, Chung-lin, e 葉重麟. "STUDY OF LED CURRENT BALANCE FOR PARALLEL STRING CONFIGURATION". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/36754294906447267668.
Texto completo da fonte大同大學
電機工程學系(所)
100
In this thesis, a simply current balance method of the light emitting diodes (LEDs) string via the connection of passive components is proposed to achieve current balance and current sharing between two serial LEDs strings. In recent years, the researches of LED are proposed due to the wide applications of LED in the lightings, backlight of monitor, street lights, vehicle lamps, and so on. However, a single LEDs string does not enough to provide illumination, and therefore, the multiple LEDs strings are developed. The most important issue by using the multiple LEDs strings is the unbalanced current of each LEDs string. It causes the uneven brightness as the unbalance of every LEDs string serial current occurs. Therefore, the passive component current balance method is proposed to improve the phenomenon of the unbalanced current of each LEDs string which is caused by the different forward voltages of LEDs. The advantages of the proposed method include fewer components, low complexity, cost saving, and easy to be implemented. Finally, the simulations and experimental results verify the effectiveness of the proposed method.
Syu, Jhih-yao, e 許智堯. "Output-Cascoded Single-Stage Two-String LED Street Lamp Driver". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/81142462903183344788.
Texto completo da fonte國立臺灣科技大學
電子工程系
101
This thesis studies a modular power supply for driving an LED streetlamp with multiple strings of LEDs. A 130-W topology is proposed and verified based on the single-stage flyback converter. Operation principles of the topology are discussed and design guidelines are provided. A 100-W constant-voltage single-stage AC-DC flyback converter, and two 15-W constant-current DC-DC counterparts are implemented. The presented modular LED streetlamp driver is thus fulfilled by combining these three converters with parallel-connected inputs and cascoded outputs. An input current shaping circiut is added to raise the power factor.
Wang, Lih-Chiann, e 王儷蒨. "Induction of DNA strand break and 8-OHdG formation by lead acetate in vitro". Thesis, 1997. http://ndltd.ncl.edu.tw/handle/75978766146279957088.
Texto completo da fonte國立清華大學
生命科學系
85
The mechanism of DNA damage induced by lead was explored in this study. Lead acetate could induce DNA strand breakage in Hepes buffer, pH 6.8, in a dose- and time-dependent manner as determined using the plasmid relaxationassay. When compared with lead, zinc acetate did not significantly induced DNA breakage. Singlet oxygen scavengers NaN3 and 2,2,6,6-tetramethyl-4- piperidone (TEMP) markedly inhibited lead-induced DNA breakage. D2O, low dosesof glutathione and 2-mercaptoethanol (singlet oxygen enhancers) could enhancelead-induced DNA breakage. Electron paramagnetic resonance (EPR) spectra showedthat singlet oxygen but not hydroxyl radical signal was detected in lead solution. Furthermore, lead-induced DNA breakage was markedly enhanced by ascorbate in a dose-dependent manner. Catalase, NaN3, and EDTA significantlyinhibited lead/ascorbate-induced DNA breakage, indicating the participation ofH2O2, singlet oxygen, and lead in this reaction. This result suggests that leadpromotes ascorbate autooxidation, enhances the reduction of O2 to H2O2 simultaneously, and catalyzes Haber-Weiss reaction. Additionally, lead-inducedDNA breakage was markedly enganced by H2O2, and this induction was inhibited byNaN3, TEMP, glutathione, BSA, EDTA, and catalase. The results have indicated that singlet oxygen, lead, and H2O2 are all involved in the reaction system.Lead could cause a small amount of 8-hydrodeoxyguanosine (8-OHdG) formation in calf thymus DNA, and dose-dependent induced the formation of this adduct in the presence of H2O2 using HPLC-UV-ECDmethod. Singlet oxygen scavengers were more effective than hydroxyl radical scavengers in protection from lead/H2O2-induced 8-OHdG adducts. EPR spectrashowed that singlet oxygen signal was additively induced by lead/H2O2, whereaslead inhibited the hydroxylll radical signal induced by H2O2 in a prolongedincubation time. Taken together, singlet oxygen is an important factor for leadinduced DNA breakage. The results were well correlated to that the observation of lead -induced specific mutational spectrum may due to singlet oxygen and 8-OHdG (Yang et al., Mol Carcinogenesis: 17:181-191, 1996). This study showed that lead could function as transition metao ions Cu2+ and Fe3+ to catalyzefree radical generation.
Wu, Chu-Yen, e 吳居諺. "Design and Implementation of a Current Balance Driving System for Multi-string LED Backlight". Thesis, 2014. http://ndltd.ncl.edu.tw/handle/sexzmf.
Texto completo da fonte國立臺北科技大學
電力電子產業研發碩士專班
102
This thesis develops a current balance driver system for multi-string LED backligh. The first stage uses boost power factor correction converter operating in critical conduction mode in which power factor correction and soft switching are introduced to achieve high power factor and high efficiency. The second stage combines a half-bridge resonant converter and a boost converter. The current balance driving system can be implemented as the driving multi-string LED backlight. The half-bridge resonant converter has zero voltage switching on primary side power switches and zero current switching on the secondary side rectifier diodes. The secondary side windings of the transformer are connected to each of the multiple LED strings. The boost LED driver feedback control is used to achieve current balance for multi-string LED backlight. This thesis features power factor correction, LED current balance, a more simplified circuit topology. Finally, the design specifications for three string LED backlight include output voltage 210V, output current 260mA and AC input voltage 90V~264V. Experimental results verify that this system can meet the LED backlight driver design requirements. Power supply has efficiency up to 86%, power factor up to 0.97.
Chen, Yu-Wei, e 陳佑瑋. "Design of an AC-powered LED string adapted to the variation of the voltage applied". Thesis, 2017. http://ndltd.ncl.edu.tw/handle/14108491769480982249.
Texto completo da fonte崑山科技大學
光電工程研究所
105
This paper proposes a digital method to eliminate the conduction angle to turn on a LED string with an AC power. AC LED uses AC current directly without the need to convert it to DC current. However, AC LED flares with the vibration of the AC voltage, which might introduce an unsteady lighting effect to human eyes because of its conduction angle. Here, the proposed digital method is simple to implement and able to eliminate the conduction angle almost. In other words, the LED string driven by an AC power can light almost all the time just with its intensity following the variation of the AC voltage. In the end, the efforts having to be paid more than those using AC LED is discussed. The method proposed in this paper does help to reduce the conduction angle of the LED grain array, from the measurement results of the conduction angle is almost zero. In other words, the LED grain array can be turned on almost at any time, except that the strength of the light source exhibits a positive correlation with the magnitude of the voltage across the LED grain array. DC power supply directly to drive 38 LED crystal, according to LED (NSPW500CS, Nichia) data brochure, the need for output power 4.56W or more DC power supply; and in this article using the implementation of the circuit, the demand for DC power supply switch circuit (S1 to S14) and the operation of the microcontroller, the maximum required power consumption is about 0.536W. There is a significant difference in the volume of the transformer used inside the DC power supply, which can even use the transformer without the need for DC power supply. Although the circuit mentioned in this article is not as good as the AC LED streamlining, it can greatly improve the AC LED conduction angle problem, and the increase in circuit cost and volume is still far less than the original use of DC power supply driver LED grain way.
ZENG, GUAN-CI, e 曾冠綺. "Study and Implementation of a High-Performance Driver for Multi-Parallel LED Strings". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/61217946129115913068.
Texto completo da fonte國立臺灣科技大學
電子工程系
96
A high performance light-emitting diodes (LED) driver is proposed in this paper. The circuit of this driver consists of a voltage pre-regulator and multiple linear current regulators. We propose a kind of control method to keep the linear current regulator with highest performance. This method makes the surplus voltage of the linear current regulator close to zero, and drive the multi-parallel LED’s brightness the same. The tradition control method of the voltage pre-regulator is using the across voltage between drain gate and source gate of the linear current regulator’s MOSFET. The resistance between MOSFET’s drain and source (RDS(on)) changes with temperature. That is the problem why the voltage pre-regulator can’t operate in the best performance automatically. This paper proposed a control method with voltage pre-regulator using MOSFET’s gate voltage. This method has following advantages: simple design parameters, independent of temperature, and the ability to control the voltage pre-regulator immediately when the load changed. This paper analyzes the circuit in detail, and practices to prove it feasibility. The experiment results show that this method can increase the performance in the multi-parallel LED application effectively.
Lin, Cheng-hsien, e 林政賢. "Study and Implementation of a Dimmable LED Driver with Multi-string Current Balance and Low Switch Voltage Stress". Thesis, 2013. http://ndltd.ncl.edu.tw/handle/05305942816712179259.
Texto completo da fonte國立臺灣科技大學
電子工程系
101
This thesis studies and implements a dimmable LED Driver with multi-channel current balance and low switch voltage stress. The front stage is a single-stage flyback power factor corrector (PFC) converter which features high conversion efficiency, high power factor (PF) and simple topology. It supplies the main output current and a constant output voltage to the LED module. The post-stage is a buck converter which outputs an accurate current to the LED module and fulfills the multi-channel current balance and dimming functions. The buck converter is of a floating ground configuration which features small volume and high conversion efficiency. The proposed LED driver is composed of a flyback PFC cascaded by a floating ground buck converter, resembling a voltage source in series with a current source. At most three LED strings can be driven. Within the designed voltage range, the number of LEDs in one string can be adjusted and various types of lamps can be adopted. The proposed dimmable driver with current balance can lower the switch voltage stress. Therefore, the power loss and circuit cost can be reduced.