thermistor; time-periodic solution; Hopf bifurcation
A system of ordinary differential equations modelling an electric circuit with a thermistor is considered. Qualitative properties of solution are studied, in particular, the existence and nonexistence of time-periodic solutions (the Hopf bifurcation).
 J. Guckenheimer, P. Holmes: Nonlinear Oscillations, Dynamical Systems and Bifurcation of Vector Fields
. Springer-Verlag, New York Inc., 1983. MR 0709768
 F.J. Hyde: Thermistors. Iliffe Book, London, 1971.
 J.J. Marsden, M. McCracken: The Hopf Bifurcation and its Application
. Springer-Verlag, New York Inc., 1976. MR 0494309
 Ambrosetti, G. Prodi: A Primer in Nonlinear Analysis. Academic Press.
 R.W.A. Scarr, R.A. Setterington: Thermistors, their theory, manufacture and application. The Institution of Electrical Engineers 3176 M, Jan., 1960.