Splice: A New Analytical Network Analysis Software

Thomas G. Engel
CaaGE Software
408 North Village Circle
Columbia, Missouri 65203
Phone: 314-443-4048
Fax: 314-443-4048
70602.2575@compuserve.com

Abstract:

Splice is an analytical electrical circuit analysis program that operates under the Windows operating system. At the present time, Splice is the only commercially available software that will perform this type of analysis. A description of the features found in Splice 1.0 and examples to illustrate them is presented. Splice is easy to use and works with the netlist file of the MicroSim Corporation PSpice simulator. The user adds special ``analysis symbols'' to the circuit schematic which instruct Splice to perform a specific type of analysis. The analysis symbols are transparent to PSpice giving the user the option to simulate the network at any time. Splice is powered by the Waterloo Maple Software algebraic engine and will analyze many types of linear electrical networks consisting of inductors (with initial conditions), capacitors (with initial conditions), resistors, transformers, transistors (bipolar and field-effect), operational amplifiers, and all types of AC and DC (independent and dependent) current and voltage sources. Splice will perform branch current, nodal voltage, Thevenin reduction, transfer function, and two-port reduction analysis with options for component substitutions (both numeric and/or symbolic including zero and infinity), pole and zero calculations, sinusoidal steady state analysis, and time domain result calculations. At the present time, Splice cannot solve networks with non-linear components, it can reduce the linear network surrounding a non-linear element allowing the user to attempt an analytical solution. From computer assisted homework to in-depth circuit analysis, Splice provides for better, more insightful linear electrical network analysis.

Introduction

Simply stated, Splice 1.0 is an analytical solver for electrical circuits and networks. It is the only commercially available software that gives exact, closed-form solutions for most electrical circuit parameters of interest in either symbolic, numeric, or mixed symbolic-numeric form and promises to fill the apparent void that exists between theoretical circuit analysis (as presented in college level courses) and numerical circuit simulation. Although it has not been employed in the classroom at the present time, it has proven itself to be a useful software tool to the various experienced engineers who have used it. Splice is easy to use and runs under the intuitive Windows graphical user interface. It is also quite powerful. It works in conjunction with PSpice [1], the industry-standard numeric circuit simulator, allowing the user to create a circuit by intuitive graphical means and accurately simulate it (the evaluation version of PSpice version 6.1a is shipped with Splice). Splice uses the netlist file created by PSpice allowing the user obtain an exact solution for the quantity of interest. Drawing on the mastery of the Maple V algebraic engine [2] and the circuit analysis expertise at CaaGE software, Splice will analyze most types of linear (and some linearized) electrical networks for many types of circuit analysis. Splice also provides for the ``other calculations'' associated with any type of analysis. All Splice calculated results can be copied into other Windows programs including word processors (to be used in publications) and mathematical analysis programs (to further manipulate the results) such as Maple V. Splice is beneficial to all types of technical, and some non-technical, personnel including educators, engineers, scientists, students, and technicians. From computer assisted homework to in-depth circuit analysis, Splice can assist the user in better, more intelligent investigations of linear electrical networks.

This paper will focus on the basic operation of Splice 1.0 (i.e., the types of analysis and components supported) and its potential applications in electrical engineering education. Curriculum can be in circuit theory, electronics, project laboratories, and control and systems theory. The course material can be structured around Splice where the instructor would encourage the student to try ``what-if'' scenarios helping the student to develop his ability to think abstractly. Or, Splice can be used by the student to check answers, providing immediate feedback which would increase the rate of his learning. Both strategies encourage the student to examine the mathematical form of the answer and understand the implications of that form. ``What are the salient terms and components,'' ``what terms can be neglected,'' and ``what does this answer really mean,'' are a few examples of the kinds of critical thinking that needs to be developed in students for them to be good engineers. Splice is also useful to the instructor and provides a quick and accurate method to cross-check his notes.

Description Of Operation

The network is first created in PSpice using conventional components. PSpice has a graphical schematic entry program which greatly speeds the creation of the electrical circuit. Next, special symbols called ``analysis symbols'' are to the circuit. The analysis symbols recognized by Splice 1.0 include branch current, nodal voltage, Thevenin reduction, transfer function, and two-port reduction analysis and are shown in Figure 1 as they appear in schematic entry program of PSpice. The circuit is then saved to disk and a netlist file is created. The netlist file is then opened in Splice. Figure 2 illustrates the Splice main menu and the various analysis options available to the user. These options include component substitutions (both symbolic and numeric including zero and infinity), poles and zeros calculations, sinusoidal steady state calculations, and time domain results. Note that these solutions options are not all available simultaneously and depend upon the type of analysis that is being performed.