Utilisation de la Magnéto-Impédance Géante pour la réalisation d'un capteur de courant

In this thesis we aim to realize a contactless GMI current sensor. The electronic conditioning of the sensor has been deeply investigated. Particular attention has been paid to the exciting alternate current of the sensitive element and the measurement circuit of the voltage change across it. A new accurate, stable and high frequency digital oscillator (DDS) was proposed. A voltage-to-current converter based on the Howland pomp was associated to this oscillator. For voltage measurement and amplitude demodulation, innovative and promising solutions have been proposed. A first solution uses a new generation of RMS-DC converters for accurate measurements. An adequate electronic conditioning of this detector allows using it in a GMI sensor for both AC and DC current measurement. Also a second original approach of amplitude detection without threshold limitation, using a limiter amplifier has been developed and successfully incorporated into a GMI current sensorCette thèse explore le potentiel de la Magnéto-Impédance Géante (GMI) pour la réalisation d’un capteur magnétique de mesure du courant électrique sans contact. Une partie notable a été consacrée à l’investigation de l’électronique de conditionnement du capteur, notamment, l’électronique d’excitation de l’élément sensible et l’électronique de détection et de démodulation de l’amplitude de la tension à ses bornes. Une nouvelle solution d’oscillateur numérique, utilisant la technologie DDS a été proposée. Un convertisseur tension-courant basé sur la source de Howland a été associé à cet oscillateur. Pour la détection, des techniques et méthodes innovantes et prometteuses ont été proposées. La première technique utilise une nouvelle génération de détecteur RMS-DC pour les mesures précises. Un conditionnement électronique approprié permet d’utiliser ce détecteur dans un capteur GMI pour la mesure de courant AC/DC. Une deuxième approche originale de détecteur d’amplitude sans seuil utilisant un amplificateur limiteur a aussi été développée et intégrée avec succès dans un capteur GMI de courant électrique

Digitally-assisted, ultra-low power circuits and systems for medical applications

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 219-225).In recent years, trends in the medical industry have created a growing demand for a variety of implantable medical devices. At the same time, advances in integrated circuits techniques, particularly in CMOS, have opened possibilities for advanced implantable systems that are very small and consume minimal energy. Minimizing the volume of medical implants is important as it allows for less invasive procedures and greater comfort to patients. Minimizing energy consumption is imperative as batteries must last at least a decade without replacement. Two primary functions that consume energy in medical implants are sensor interfaces that collect information from biomedical signals, and radios that allow the implant to communicate with a base-station outside of the body. The general focus of this work was the development of circuits and systems that minimize the size and energy required to carry out these two functions. The first part of this work focuses on laying down the theoretical framework for an ultra-low power radio, including advances to the literature in the area of super-regeneration. The second part includes the design of a transceiver optimized for medical implants, and its implementation in a CMOS process. The final part describes the design of a sensor interface that leverages novel analog and digital techniques to reduce the system's size and improve its functionality. This final part was developed in conjunction with Marcus Yip.by Jose L. Bohorquez.Ph.D

EUROSENSORS XVII : book of abstracts

Fundação Calouste Gulbenkien (FCG).Fundação para a Ciência e a Tecnologia (FCT)

Applied Measurement Systems

Measurement is a multidisciplinary experimental science. Measurement systems synergistically blend science, engineering and statistical methods to provide fundamental data for research, design and development, control of processes and operations, and facilitate safe and economic performance of systems. In recent years, measuring techniques have expanded rapidly and gained maturity, through extensive research activities and hardware advancements. With individual chapters authored by eminent professionals in their respective topics, Applied Measurement Systems attempts to provide a comprehensive presentation and in-depth guidance on some of the key applied and advanced topics in measurements for scientists, engineers and educators

Payload operations control center network (POCCNET) systems definition phase study report

The results of the studies performed during the systems definition phase of POCCNET are presented. The concept of POCCNET as a system of standard POCCs is described and an analysis of system requirements is also included. Alternative systems concepts were evaluated as well as various methods for development of reliable reusable software. A number of POCC application areas, such as command management, on board computer support, and simulation were also studied. Other areas of investigation included the operation of POCCNET systems, the facility requirements and usage

Department of Defense Dictionary of Military and Associated Terms

The Joint Publication 1-02, Department of Defense Dictionary of Military and Associated Terms sets forth standard US military and associated terminology to encompass the joint activity of the Armed Forces of the United States. These military and associated terms, together with their definitions, constitute approved Department of Defense (DOD) terminology for general use by all DOD components

Nascom System Development Plan: System Description, Capabilities and Plans

The NASA Communications (Nascom) System Development Plan (NSDP), reissued annually, describes the organization of Nascom, how it obtains communication services, its current systems, its relationship with other NASA centers and International Partner Agencies, some major spaceflight projects which generate significant operational communication support requirements, and major Nascom projects in various stages of development or implementation

GMI Magnetic Sensor Operating with a Direct Digital Synthesizer (DDS)

International audienc

GMI magnetic sensor operating with a Direct Digital Synthesizer (DDS)

International audienc

Joint Publication 1-02

The Joint Publication 1-02, Department of Defense Dictionary of Military and Associated Terms sets forth standard US military and associated terminology to encompass the joint activity of the Armed Forces of the United States. These military and associated terms, together with their definitions, constitute approved Department of Defense (DOD) terminology for general use by all DOD components. This publication supplements standard English-language dictionaries and standardizes military and associated terminology to improve communication and mutual understanding within DOD, with other federal agencies, and among the United States and its allies