Tracing characteristics of smooth nonlinear resistive circuits by interval analysis

An algorithm for tracing solution curves of one-port nonlinear resistive networks, based on the covering of the solution set by a collection of n-dimensional boxes, is presented. The covering algorithm, developed from interval techniques, guarantees that every unicursal branch of the characteristic is captured and it is well suited to render the resulting curves on a graphics display. In addition, a new zero inclusion test for circuit equations in the hybrid form is introduced. This strategy, on the one hand has been proved to be effective in improving the quality of the analysis, while on the other hand has been able to considerably increase the performance of the method. As an application of the method the driving-point and transfer characteristics of a tunnel diode circuit are finally presented.