Modeling Linear Electrical Circuits with Time-Variable Inductances by the Frequency Symbolic Method

The paper presents the way of formation the system of differential equations, which describes a linear circuit with variable inductances by the method of the nodal voltages, and their transfer in the frequency domain using the L. A. Zade's equation. Peculiarities of formation transfer functions of circuits with variable inductances by frequency symbolic method are considered. Here are given results of solving the systems of the linear algebraic equations (SLAE), which are formed in process of analysis of such circuits. The described approach is implemented in the system UDF (user-defined functions) MAOPCs (multivariate analysis and optimization of parametric circuits), which is used in modeling of the circuits, specifically, parametric amplifiers in special purpose receivers.