THERMODEPENDENT POLYCRYSTAL RESISTORS IN STARTERS OF ELECTRIC MOTORS OF LIFTING AND TRANSPORT MACHINES

The purpose of the work is to create an engineering procedure for the synthesis of starting rheostats on semiconductor thermo-resistors (STR) ensuring a simple and reliable start of electric motors. The developed procedure for the synthesis of starting rheostats based on STSs allows designing simple-formed, small cheap and reliable in operation starting devices of all kinds. There is developed a universal method of the synthesis of STR-based starting rheostats based on two installed invariants of the similarity of starting processes connecting specified starting indices with the parameters of STR-based rheostats. The method applies to different types of electric motors taking into account: - changing temperature conditions of environment; - quantitative indices of semiconductor material; - different types of thermo-resistors. A corresponding algorithm of for the computation of STR-based starting rheostats is developed. It is proved that a field of thermo-resistor rheostat application is dc and ac electric motors. In the paper there are shown design peculiarities of semiconductor thermo-resistor creation and a number of limitations on which a character of starting electric installations depends are formulated.