Find in Library

The characteristics of a two-layer structure on the basis of the layers of varistor ceramics and polymeric PPTC nanocomposite being in thermal contact for the purpose of using it as a limiter of constant voltage and long-term varying electrical overvoltages are analyzed. A theoretical model of such a structure has been developed, and its main electrical characteristics are simulated. It is shown that the provision of the required output voltage limitation is performed by selecting the classification voltage of the varistor layer. The maximum current of the varistor layer required for heating the structure is determined by the intensity of heat transfer to the environment. It has established a satisfactory agreement between the theoretical and experimental electrical characteristics for the structure based on the layers used in commercial varistors and PPTC fuses.