Pavel Steffan

A comparative study on different moduli sets in residue number system

This paper presents a comparative study on different moduli sets that are used in the Residue Number System (RNS). Choosing a proper moduli set is one of the most important issues in RNS. It greatly affects the performance of the whole system. Many moduli sets have been introduced recently, each of them has its own advantages and disadvantages. Therefore, the necessity to a survey and a comparison between these sets is obvious. This paper demonstrates a detailed study on time and hardware requirements of residue-to-binary converters (RC) and residue arithmetic units (RAU), based on each of the studied sets, categorized by the dynamic range (DR) they provide. Then, the most efficient moduli set for each DR is suggested. The effect of moduli number on the systems performance and complexity is also discussed. Our research is aimed for designs whose main goal and strategy is balanced.

Single Chip Potentiostat Measurement System

The paper describes new approach of potentiostat for very low sensor current measurements. Recent potentiostats were used as measurement devices which were standalone and sensors were connected by a screened wire. These concepts are inconvenient for the presented very low current measurements. The new approach is based on the potentiostat circuitry integrated on a chip that should be directly contacted to a Thick Film Technology (TFT) sensor.

Electronic interface for differential pressure sensor

This paper describes the design and construction of an electronic interface for the differential capacitance sensor of pressure. The 14-bit precision of measurement is required. The total power consumption below 5 mW and galvanic separation is needed.

Control unit for smart concrete used as resistive heating

This paper deals with conductive concrete materials and its testing and controlling. Multipurpose remotely-controlled thermostat, called iTHERMST, was designed and built to test and evaluate new samples of the cement-based material with high specific heat and high thermal conductivity. iTHERMST tests and collects various data that can be imported directly to PC software for further evaluations. New possible controlling algorithms were introduced, described and finally tested in practice.

A New Measuring Method Suitable for Measuring Shielding Efficiency of Composite Materials with Carbon Fibers

This paper deals with the theoretical and practical aspects of the measurement of shielding efficiency. An alternative method of these measurements is described in this contribution. The theoretical design, the measured results and parameters of measurement circular flange are discussed in other parts of the paper. Carbon fibers are electrically conductive and can be added to cement to enhance the shielding effectiveness. The paper describes possible methods for measuring shielding efficiency of concrete materials with carbon fiber.

A Microconductometer Utilizing Bipolar Pulse Method for Electro-Chemical Sensors

The microelectronic measuring system for conductivity electro-chemical sensor measurement of liquid materials properties was designed in AMIS CMOS 0.7 mum technology. The main parts of the system are current source with switchable subranges, the sensor switches allowing change of the current polarity in compliance with the bipolar pulse method, which was developed specially for this measurement purposes at the Dept. of Microelectronics. The most important part of the system is a sensor voltage drop measuring circuit using opamps offset switched compensation.

Intelligent radiant floor heating regulation system with wireless sensors

Thermal comfort of person living in building with radiant floor heating is not usually perfect. There is usually absence of control system based on each single room. This work proposes a simple, promising, effective and cost-effective regulation system for radiant floor heating. Designed system is based on small wireless sensors placed in every room to measure the temperature and wirelessly send it to the cloud. The data is analyzed and compared with user selected values and appropriate actions are taken by wireless relay unit that controls flow through each heating circuit by thermoelectric actuators. Main benefits of this system is Internet of Things (IoT) solution, which means that all the computing is made in the cloud. Used sensors and relay board can be relatively cheap due to low demands on its computing power. There is not any expensive main unit with display and user interface, because this system can be controlled via cloud from any kind of device (such as notebook, tablet, smart phone etc.). Prototype have been tested in a normal environment for its basic functions, but more data needs to be measured for final verification.

The System for Detecting Lead in Solders

This article describes the design system for the determination of lead in solders used in electrotechnic industry. It were studied and proved methods of electrochemical detection focused on heavy metals. The general aim is principles of quantitative heavy metal detection by the electrochemical methods, optimal method selection and construction of detecting instrument.

New Micropotentionstat for Measurement Responses from Thick-Film Sensors

The new solution of the amperometric sensor measurement is given. It solves the problem of measurement of low currents (in order of nA) from electrochemical biosensors. However the sensitivity of integrated measurement system, which process output currents from biosensor, has to be in order of pA. There are leakage currents and noise constraints which could be avoided by on chip solution. The on-chip solution allows direct chip connection on the basic ceramic plate of biosensors. It means the idea is similar to hybrid integrated circuit. Main advantage of this solution is separating sensitive low potential and low current ASIC electronics placed just on the TFT sensor from control and supply electronics of portable device. Additional advantages of the sensors fabricated using TFT are low cost, small dimensions, good reproducibility, chemical, mechanical and electrical properties of electrodes and well accessible and ecological fabrication process.

Composite Materials for Electromagnetic Interference Shielding

This paper demonstrates that the addition of chemical agents and carbon fibers to cement can greatly enhance the shielding effectiveness of the concrete. In addition to improving the shielding effectiveness, carbon fibers and chemical agents enhance the tensile and flexural strengths significantly. As both carbon fibers and steel fibers are electrically conductive, both can be added to cement to enhance the shielding effectiveness, but steel fibers tend to rust whereas carbon fibers are chemically stable and inert.