The use of high-power thermistors as part of the control gear facilitates a smooth start-up of powerful motors with simultaneous temperature control. When calculating the starting processes, there are a number of limitations on which the nature of starting electric motors with the use of thermistor rheostats depends. The calculated relations describing the mathematical model of the influence of the temperature of overheating of semiconductor thermistors on the process of starting motors with a start-up rheostat are presented in the form of graphic dependences. As a result of modeling the layout of thermistor rheostats, it was determined that it is necessary to pay special attention to the material heating temperature.

Keywords: semiconductor thermistor, starting rheostat, boundary conditions, heating, specific heat, induction motor, starting current, overheating temperature

The problem of creating semiconductor thermoresistors (PTR) capable of dissipating large amounts of heat is an urgent problem of semiconductor technology. The article presents a brief analysis of the possibilities of using high-power ATGM, the picture of the distribution of thermal fields in the mass of the thermistor under certain boundary and initial conditions. It is shown that when selecting a thermistor material, special attention should be paid to the specific thermal conductivity of the material.

Keywords: High power thermistors, current density, thermal conductivity, energy balance, similarity criteria

Launch and control circuit systems built on traditional devices represent complicate multi-link system. Its liability is determined by a number of intermediate devices. Launch jaggedness – is one of the significant flaws, negatively affect on launching process dynamics. Promising direction of launch and control circuits devices are rheostats built on high current semi-conduct polycrystalline thermistors. At the article short analysis of electrotechnical devices launch processes is given. A power engines launch process with thermistor rheostats is considered and formulated a number of limits. Graphic dependences characterizing launch current and rotating moment at direct launch changing and with rheostats on thermistors are given. An example of launch current for asynchronic engine with phase rotor calculating is given as well.

Keywords: semiconducting thermos-resistance, launch rheostat, launch currents curves, generalized constant, automation.

Application of low-power thermal resistors in starters requires availability of intermediate equipment and various components. It significantly reduces the reliability of the equipment. Increase in currents flowing through the pre-regulating devices simplifies electrical schematic of the control and regulation. To use thermal resistors in circuits with high currents it is necessary to use special designs, for the purpose of thermoresistor's material overheating prevention. Algorithms for synthesis of starting rheostats are given. The dependences characterizing different starting models are given.

Keywords: semiconductor thermal resistance, starting current models, generalized current characteristics

The short analysis the direct-current motor running with the help of regulating resistors and thermostatic resistors is made. A fixed range of thermistor resistors can be obtained by optimizing the current. There are some graphical dependence of the load moment influences on the engine acceleration through the semiconductor rheostat. The authors give some warning to combine starting rheostats.

Keywords: thermistor, starting rheostat, direct-current motor, motor starting current line graph, combined starting resistance

Electrotechnical devices starting processes short analysis is done including limited power autonomous system. The electrical installation starting processes with thermistor rheostats character depend on considered and formulated number of restrictions. The graphic depending’s are given characterizing different start models. The recommendations are given to form optimal starting processes with rheostats built on semiconductors polycrystalline thermistors.

Keywords: semiconductor thermoresistance, electrical installation, starting current, starting model, starting rheostat, starting processes dynamics