# equivalent circuit

## Mathematical model of magnetic state of single-phase commutator motor

Single-phase commutator motors (SPCM) with sequential excitation have a simple design and low cost, and therefore promising for use in the drive of household appliances and electric hand tools. This necessitates the creation of mathematical models of SPCM, which would allow both the development of new and modernization of existing models of such motors. The aim of the article is to create an engineering mathematical model of the magnetic state of SPCM using circular methods.

## Mathematical Model of Magnetic State of Permanent Magnet Direct Current Motor

There is a tendency of replacement of small direct current motors with electromagnetic excitation on permanent magnet direct current (PMDC) motors nowadays. PMDC motors are widely used and that is why a task of creation of mathematical models of this type of motor is actual. The aim of the article is creation of mathematical model of magnetic state of PMDC motors on the basis of theory of electric and magnetic circuit.

## Алгоритм синтезу SPICE схем заміщення гальваномагнітних перетворювачів Холла

The work presents an algorithm of synthesis of SPICE equivalent circuits for galvanomagnetic sensors based on Hall devices. By means of typical library elements circuits were composed in order to take into account magnetic values and sensor’s orthogonal coordinates that are not supported by SPICE. The obtained modeling results fit the results of experimental investigations and form the basis of the sensor’s calibration procedure.

## Mathematical model of permanent magnet direct current motor

Nowadays there is a tendency towards the replacement of small direct current motors with electromagnetic excitation by permanent magnet direct current (PMDC) motors. Application of field methods for simulation of PMDC motor complicates its mathematical model and requires considerable amount of time for the processing of the results obtained. The purpose of the paper is development of a mathematical model of PMDC motor on the basis of theory of electric and magnetic circuits.

## Methodical errors of measurement of the human body tissues electrical parameters

Sources of methodical measurement errors of immitance parameters of biological tissues are described. Modeling measurement errors of RC-parameters of biological tissues equivalent circuits into the frequency range is analyzed. Recommendations on the choice of test signal frequency for measurement of these elements is provided