928 research outputs found
High Frequency DC-DC Buck Converter for Automotive Post-Regulated Applications
No full textThe current trends in the automotive market are pushing toward an ever increasing integration of electronic components in a car. Modern cars need to be safer and smarter, hence there is the need of a lot of sensors, radars, microcontrollers etc. Consequentially, the power supply circuits that are needed to power up all these devices starting from the 12-V battery of a car are also facing an intense thrust to integration. More integration of the power supply circuits means that the production costs and area of the components are significantly reduced, but leads to less flexibility of the circuits and less robustness to high temperatures. The traditional approach was to directly convert the battery voltage to each desired lower voltage using either low dropout regulators(LDOs) or switching DC-DC converters, depending on the application. Nowadays a post-regulated approach is preferred: one converter downshifts the battery voltage to an intermediate one, typically in the range of 4∼8 V, and that intermediate voltage can either directly supply some circuits, or be the input of multiple successive regulators, that will each power up the circuits that require lower supply voltages. While complicating the design, this approach is preferred due to a higher efficiency, and the possibility of a more robust thermal isolation of the circuits. Switching DC-DC converters are usually very expensive and bulky, and this is mostly due to the presence of the inductor, which can often cost more than the chip itself, both in terms of money and area consumption. The typical switching frequency of a DC-DC converter is a few MHz. By increasing the switching frequency, a much lower inductance value can be used without degrading the current ripple. Having a lower value of inductance means that the physical dimension of the inductor is smaller, resulting in an advantage in chip cost and area. In the field of power converters, efficiency is obviously another key parameter, especially in the field of automotive where a high efficiency is beneficial for both environmental and economical reasons. The main topic of this PhD research is the study and of this research is the study and the design of a buck converter with specifications aligned with the post-regulated domain, switching at 50/100 MHz. This work has been possible thanks to the collaboration between the University of Pavia and Infineon Technologies Italy, with help from both the Pavia and Padova sites.
The second topic of this thesis is the design of a Hybrid Single-Inductor Bipolar-Output DC–DC Converter with Floating Negative Output for AMOLED Displays. As AMOLED Displays have become one of the standard technologies for mobile and TV screens, the research for more compact and efficient solutions for the supplies of the pixels is thriving. As AMOLED displays need two supply voltages (one positive and one negative) to turn on, two separate DC-DC converters are typically used to provide the necessary voltages from the battery. A Single-Inductor solution can generate both voltages with only one inductor, hence saving a lot of money and area on the chip. This part of the work has been conducted thanks to the collaboration between the University of Pavia and the University of Macau
Video for On the Design of High Switching Frequency DC-DC Buck Converter Power Stages for Automotive Post-Regulated Applications
No full text
A Florentine family in crisis: the Strozzi in the fifteenth century.
No full textPhDIn 1434 the Strozzi lineage had held a leading position in
Florentine society and government for at least one hundred and fifty
years, and was one of the largest and wealthiest of the city's
patrician lineages. The records of the catasto of 1427 and of the
scrutiny of 1433 are used to give a profile of the dominant social,
economic and political position of the Strozzi before the advent of
Medicean dominance. Their record of electoral success, and the
political and cultural leadership of influential and respected men
such as Palla di Nofri and Matteo di Simone, with other factors, put
the Strozzi amongst the greatest enemies of the victorious Medicean
regime of late 1434. The effects of political opposition and exile
on the lineage are examined both directly, through records of office-holding,
and indirectly through such indicators as marriage alliances
and household wealth. The two most prominent lines of the Strozzi
were exiled after 1434. Palla di Nofri's life and preoccupations in
his Paduan exile are examined, together with the lives of his sons;
none of these Strozzi ever returned to Florence, pursued as they were
by the enmity of the Medicean regime. The very different careers of
Filippo di Matteo and his brother Lorenzo are also examined: how they
succeeded in founding a lucrative bank in Naples, and in returning to
Florence to 'rebuild' (rifare) the position of the Strozzi lineage
there. The final decades of the century saw the Strozzi in an
economically more secure position, due substantially to the efforts
of Filippo. Except for a very small number of its members admitted
into the regime, most of the lineage is here shown to have remained
excluded from significant political office until after the fall of
the Medici regime in 1494
Vues présentes sur le celtique cisalpin
No full textPresent views on Cisalpine Celtic.
During the last twenty years, the knowledge of Lepontic and of Italian Gaulish has been notably enriched by very important finds, and also by numerous studies. The author proposes a synthesis of all new linguistical and cultural data provided by epigraphy in this particular resort.Dans les vingt dernières années la connaissance du lépontique et du gaulois d’Italie a été notablement enrichie par certaines trouvailles fort importantes ainsi que par de nombreuses études. Tableau synthétique des nouvelles données linguistiques et culturelles apportées par l’épigraphie de ce domaine.Motta Filippo. Vues présentes sur le celtique cisalpin. In: Etudes Celtiques, vol. 29, 1992. Actes du IXe congrès international d'études celtiques. Paris, 7-12 juillet 1991. Deuxième partie : Linguistique, littératures. pp. 311-318
Occhi pieni e mani vaganti. Movimenti, emozioni, astrazioni.
No full textFilippo FIMIANI, Occhi pieni e mani vaganti. Movimenti, emozioni, astrazioni, «Fata Morgana», 12/2010, pp. 147-164. ISSN 1970-5786.
ITALIANO. Una piccola sequenza da un episodio della serie televisiva Mad Men in cui la relazione sensoriale emozionale tra lo spettatore e un corpo in movimento, precisamente un corpo danzante, è l’oggetto di questo articolo, che intende così verificare la cosiddetta naturalizzazione della fenomenologia e del corpo vissuto operata dalle scienze cognitive applicate agli studi visuali. L’autore mostra anche i rapporti tra la cosiddetta simulazione incarnata e una memoria simbolica e iconografica profonda, e discute in particolare la polarità tra proiezione e introiezione, attività e passività nell’esperienza empatica delle immagini in movimento.A short filmic example from the AMC's award-winning series Mad Men in which the sensorial and emotional relationship between the spectator and a moving body, i.e., a dancing body, is explicitly put into play. The essay wants to deal with the so called naturalization of phenomenology and of the living body, trained by the cognitive sciences reading the visuality. The author shows the relationship between the so called ‘embodied Simulation’ and a symbolic and iconographic deep memory of the pictures, and he gives an in-depth attention to the polarity between projections and introjections, activity and passivity of the spectator’s body during the empathic experience of the moving pictures
Multiple political geographies
No full textThis chapter delves into the multifaceted realm of political geography within the context of the journal Political Geography. The author, who has held various editorial positions within the journal, navigates the intricate terrain of diversity and inclusion, exploring the challenges posed by linguistic and cultural biases inherent in academic publishing. The chapter critically examines efforts to mitigate barriers and broaden the scope of political geography, questioning the adequacy of current approaches. Through a reflective analysis, the author elucidates the complex dynamics of political geography as a subdiscipline, shedding light on both the impediments and possibilities it offers to researchers and students
Erratum to: Lung Tissue Damage Caused by Heat Accumulation from Adjacent Laser Application: Surgical Implications (Thoracic and Cardiovascular Surgeon (2014) DOI: 10.1055/s-0034-1389086)
No full textIt has been brought to the Publisher's attention that the author names "Filippo Lococo" and "Alfredo Cesario" were not listed correctly in the above-mentioned article, published on eFirst on September 5, 2014. DOI of the original article is DOI: 10.1055/s-0034-1389086. The names should be read as "Filippo Lococo" and "Alfredo Cesario" in place of "Lococo Filippo" and "Cesario Alfredo."
Fasti di Lodovico XIV. il Grande : esposti in versi in occasione dell'esser levato al sacro fonte il primogenito del marchese Filippo cavalier Sampieri in nome di S.M. Cristianissima.
No full textIllustrated with etchings, comprising a portrait of Louis XIV by Francesco Maria Francia, and 12 plates by Lodovico Mattioli.Each of the twelve cantos is by a different author. Names supplied in manuscript in table of contents, p. [1] at end.Dedication signed: Filippo Sampieri.Imprint from colophon.Signatures: pi⁴ A-O⁸ P⁴.Mode of access: Internet.Bound in old vellum; ink title and library shelf mark on spine
Design of a capacitive-coupled integrated circuit for adaptive dead time control and short-circuit fault detection in industrial motor gate drivers
No full textLAUREA MAGISTRALEGli inverter di potenza sono impiegati nei convertitori a frequenza variabile per pilotare motori elettrici industriali e controllarne con precisione la velocità. In questi sistemi, due transistori di potenza ad alta tensione sono configurati in una "gamba di inverter" e commutati alternativamente per generare una tensione a modulazione di larghezza di impulso (PWM) sulla fase del motore, producendo la corrente a bassa frequenza necessaria. A causa delle asimmetrie nella commutazione dei transistor, se i segnali di accensione e spegnimento vengono emessi contemporaneamente, può verificarsi una conduzione simultanea, rischiando di cortocircuitare il bus DC. Per evitare questo fenomeno viene introdotto un ritardo fisso, noto come "dead time", tra la commutazione dei due dispositivi. Durante questo intervallo, la natura induttiva del motore forza la corrente di carico a fluire attraverso i diodi di body dei transistor, causando dissipazione di potenza, perdite di energia e distorsione armonica nella corrente di uscita. Minimizzare il dead time può essere vantaggioso; tuttavia, la sua durata ottimale varia durante il ciclo del motore ed è influenzata dalla polarità della corrente di carico e dal tipo di transizione di commutazione. In questa tesi è stato sviluppato un circuito integrato che determina e applica il dead time ottimale senza la necessità di misurare direttamente la corrente del motore. L’architettura proposta, realizzata con tecnologia BCD fornita da Infineon Technologies, stabilisce il dead time ottimale rilevando la polarità della corrente di carico tramite la misura della velocità di variazione (dV/dt) del nodo di commutazione Vs, utilizzando un condensatore ad alta tensione integrato. L’architettura è stata testata tramite simulazioni, confermando che riduce significativamente il dead time, diminuendo la dissipazione di potenza e la distorsione armonica a bassa frequenza nell’uscita. Infine, è stata implementata e verificata la funzionalità aggiuntiva di rilevamento di cortocircuiti sul carico, ottenuta sfruttando i segnali generati dal blocco per l’ottimizzazione del dead time, con l’aggiunta di una minima circuiteria logica.Power inverters are used in Variable Frequency Drives (VFDs) to drive industrial electric motors and precisely control their speed. In these systems, high-voltage power transistors are configured in inverter legs and alternately switched to produce a Pulse Width Modulated (PWM) voltage on the motor phase, which in turn generates the required lower-frequency current. Due to inherent asymmetries in transistor switching, simultaneous conduction may occur if the turn-on and turn-off signals are issued at the same time, potentially shorting the DC bus and damaging the system. To prevent this, a fixed delay, known as dead time, is introduced between the switching of complementary transistors. However, during this interval, the inductive nature of the motor forces the load current to flow through the transistors’ body diodes, resulting in power dissipation, energy losses, and harmonic distortion in the output current. Minimizing dead time can therefore be beneficial; however, its optimal duration varies throughout the motor cycle, influenced by factors like load current polarity and the type of switching transition. In this thesis, an integrated circuit that determines and applies the optimal dead time without the need for direct motor current sensing has been developed. The proposed architecture, implemented using a BCD technology with deep trenches capability provided by Infineon Technologies, determines the optimal dead time by first determining the load current polarity by means of switching node dV/dt sensing, using an innovative, cost-effective method based on an integrated high-voltage capacitor. The complete architecture has been fully validated through simulations, and its compliance with an existing test chip has been verified. Simulation results confirm that the design minimizes dead time to the lowest possible value, significantly reducing power dissipation and low-frequency harmonic distortion at the output. Finally, the additional feature of load short-circuit detection has been implemented and verified. This functionality is achieved by leveraging the signals produced by the current sensor, with only a minimal addition of logic circuitry
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