The paper presents an electrical model developed for Pspice simulation of the behavior of the magnetic amorphous wires working under the Giant Magnetoimpedance (GMI) effect. The model was developed in order to facilitate the design of the signal conditioning circuitry belonging to the new category of transducers whose sensitive elements are based on the GMI effect. Its complexity arises from the fact that the effect is influenced by many internal or external factors whose actions have to be taken into consideration in the designing phase. In order to assess its performances, the model was tested by simulating a magnetic field transducer whose signal processing circuit is reprezented by a Colpitts oscillator. It was found that the model provides good accuracy even in nonlinear regions of the characteristic, where the mathematical approximation is quite imprecise. Theoretically, the model can be extended to any number of input quantities, but its complexity and computation time increase exponentially. By extension, it can be successfully utilized to simulate transducers based on any other nonlinear magnetic material.

Obesity-hypertension is an emerging concept in pathophysiology. Obesity and hypertension have been turned into an epidemic afflicting all the word, being among the mainly factors that have been burning the health costs. This paper reports a study whose purpose was to develop an objective method to better diagnose and manage this pathophysiology. A data management and data mapping system was developed. Kohonen topological mapping was used in the classification of obesity-hypertension considering clinical characteristics and laboratory results. Thus, the n-dimensional space of physiopathological parameters was converted into a 2D space of the following obesity classes: healthy subject, overweight, obesity class I, obesity class I-hypertension, obesity class II, obesity class II-hypertension, obesity class III, and obesity class III-hypertension. Transient changes in the individual state could also be analyzed using the proposed self-organizing map based model. Characteristics of the designed maps, such as topology and quantification errors, were studied.

AC excitation followed by synchronous demodulation is an effective noise-reduction method for signal conditioning in modulating sensors. However, it cannot be applied to self-generating sensors such as thermocouples or piezoelectric films. Switching on and off the power supply voltage of an amplifier yields a modulated output signal and allows for synchronous demodulation. Hence, this method improves the signal-to-noise ratio (SNR) by reducing 1/f noise and reduces power consumption. Furthermore, it can be applied to self-generating sensors. A prototype system based on this method has been applied to a thermocouple signal conditioner whose power supply voltage was switched at 1 kHz. The nonlinearity error obtained was below 0.01 FSR and the SNR was 90 dB for a 1.5 Hz noise bandwidth.

The Application for Protection, Control and Meterring Circuits using a Development Microsystem, simulates protection, alarms, control and metering instruments, for 20 kV Over Head Line Feeder. The first function of present application makes a combination between coordinated and integrated systems, combining the safety of first with the fast operating of second and simulates protection operations, for the feeder described above. The second function of this application, is to command and supervise local and remote operations of Bus Bar Switches, Circuit Breaker and Earthing Switch, assuring the safety operation of each one, because of the interloks which are introduces for each specifical operation. Finally, the third function, is to analyse power quality indicators, as an digital measurement device, and being able to present selected details into four screens which are shown on the graphical display. The original contribution of this one is to count voltage, current and voltage fluctuations, out of Power Quality rules and to send alarm to the Substation Control Room.

Voltage and current transformers are the most installed transducers in electrical power system and typically they are constructed to operate at industrial frequency, 50/60 Hz. On the other hand power quality analyses in the last years has assumed more and more heaviness in industrial environments, due to the presence of non-linear loads: they require measuring instrumentation with large bandwidth. Therefore in this paper a real-time digital technique for the compensation of current transformers, based on field programmable gate array, is presented: it implements a digital filter with a frequency response equal to the inverse one of CT. The compensated CT continues to be an analog device since the FPGA board is opportunely equipped with analog to digital and digital to analog converters. Experimental results have shown that the compensated CT improves performances of the original CT of a factor 24.