Search results for "hard"
showing 10 items of 2294 documents
Monolithic integration of GMR sensors for standard CMOS-IC current sensing
2017
Abstract In this work we report on the development of Giant Magnetoresistive (GMR) sensors for off-line current measurements in standard integrated circuits. An ASIC has been specifically designed and fabricated in the well-known AMS-0.35 μm CMOS technology, including the electronic circuitry for sensor interfacing. It implements an oscillating circuit performing a voltage-to-frequency conversion. Subsequently, a fully CMOS-compatible low temperature post-process has been applied for depositing the GMR sensing devices in a full-bridge configuration onto the buried current straps. Sensitivity and resolution of these sensors have been investigated achieving experimental results that show a de…
User Activity Recognition for Energy Saving in Smart Homes
2015
Abstract Energy demand in typical home environments accounts for a significant fraction of the overall consumption in industrialized countries. In such context, the heterogeneity of the involved devices, and the non negligible influence of the human factor make the optimization of energy use a challenging task; effective automated approaches must take into account basic information about users, such as the prediction of their course of actions. Our proposal consists in learning customized structural models for common user activities for predicting the trend of energy consumption; the approach aims to lower energy demand in the proximity of predicted peak loads so as to keep the overall cons…
A microcontroller-based portable electrocardiograph recorder.
2004
We describe a low cost portable Holler design that can be implemented with off-the-shelf components. The recorder is battery powered and includes a graphical display and keyboard. The recorder is capable of acquiring up to 48 hours of continuous electrocardiogram data at a sample rate of up to 250 Hz.
A standard-compliant prototype for PV module curve detection
2014
In this paper, a prototype for PV module curve detection which features low cost and size and ensures high accuracy is proposed. The proposed architecture is based on a buck-boost converter in open-loop configuration. The proposed architecture is fully compliant with actual standard IEC60904. The duty-cycle control algorithm and its own effects on system performances are accurately investigated. The comparison of different duty-cycle patterns is carried out and performance evaluation is performed. Simulation results are shown to perform a valuable comparison of control algorithms. Preliminary experimental results on a laboratory prototype are presented.
Development of the control card for the digitizers of the second generation electronics of AGATA
2012
In this work, the features and development process of the novel control card for the digitizers of AGATA are presented. The board is part of the new hardware proposed for the electronic system of the experiment. In particular, the control card provides the sampling clock for the digitizers, contributes to the synchronization of the digital data and performs the slow control of its associated digitizer cards.
Experimental validation of a general model for three phase inverters operating in healthy and faulty modes
2012
The paper presents the experimental verification of a general mathematical model of Voltage Source Inverters (VSI) able to simulate fault conditions and which is also useful for the simulation of fault-tolerant systems for different applications. In general, in the past, the problem of faulty inverters modeling has been addressed specifically by considering faults on the different phases as separate cases. Furthermore, traditional models include only the faulty mode and not the healthy mode, so resulting then not able to predict transient phenomena. The model hereafter presented overcomes this drawback. It was formulated by introducing the concept of “healthy leg binary variables”. Such var…
Design And Characterization Of Automated Color Sensor System
2017
Abstract The paper presents a color sensor system that can process light reflected from a surface and produce a digital output representing the color of the surface. The end-user interface circuit requires only a 3-bit pseudo flash analog-to-digital converter (ADC) in place of the conventional/typical design comprising ADC, digital signal processor and memory. For scalability and compactness, the ADC was designed such that only two comparators were required regardless of the number of color/wavelength to be identified. The complete system design has been implemented in hardware (bread board) and fully characterized. The ADC achieved less than 0.1 LSB for both INL and DNL. The experimental r…
Simple Circuit Models for Studying Global Earthing Systems
2007
The paper proposes three simple circuit models for the simulation of the behaviour of a global earthing system during different fault events. The models allow one the evaluation of the maximum earth potential rise at every possible fault location and for every possible fault event. The three considered fault events are: single-line-to-earth fault inside a MV/LV substation, double-earth-fault in a MV line, single-line-to-earth fault inside a HV/MV station. After having illustrated the hypotheses at the basis of the study, the circuit models for the three fault events are presented and a numerical example shows how to use them in order to check the "global safety" of the interconnected earthi…
Quasi-digital conversion for resistive devices: application in GMR-based IC current sensors
2013
Resistive devices, including sensors, are used in a huge range of applications within different scenarios. When a complete system is considered, a quasi-digital output is often recommendable. If the conversion is operated at device level, some problems such as noise disturbs, insertion losses and so on, can be reduced. In this work, we describe a resistance-tofrequency (R-f) converter with a suggested application in low current monitoring by means of GiantMagnetoResistance (GMR) sensors. Specific devices have been designed and microfabricated. The system has been tested by means of discrete components with a PCB. The complete microsystem monolithic integration in a standard CMOS technology …
Analysis of voltage dips propagation in MV distribution networks by using ATP-EMTP code
2003
In this paper, voltage dips simulation in electric power MV distribution networks by using an improved ATP circuit-breaker model are reported. An equivalent circuit of a MV distribution system is employed. The circuit-breaker is simulated by using a tool written in MODELS language and by arranging a time-variable differential arc-conductance based on the combination of Mayr's and Cassie's equations. The simulations carried out have shown how the amplitude of the voltage dips depends on the type and location of the fault and their duration is strictly related to the circuit-breaker parameters.