SpiceSharpBehavioral

This library extends Spice# components with behavioral sources for modelling electronics circuits.

Documentation

The API can be found here

Quickstart

Including this library allows you to use two extra components:

• BehavioralVoltageSource
• BehavioralCurrentSource

using System;
using SpiceSharp;
using SpiceSharp.Components;
using SpiceSharp.Simulations;

namespace Example
{
    class Program
    {
        static void Main(string[] args)
        {
            var ckt = new Circuit(
                new VoltageSource("V1", "in", "0", 0.0),
                new BehavioralVoltageSource("A1", "out", "0", "V(in)^2+2"));

            var dc = new DC("dc", "V1", -1, 1, 0.1);
            dc.ExportSimulationData += (sender, e) =>
            {
                Console.WriteLine(e.GetVoltage("out"));
            };
            dc.Run(ckt);
            Console.ReadKey();
        }
    }
}

Installation

Spice#.Behavioral is available as a NuGet package.

Spice#.Behavioral

How does it work?

The parser parses expressions into functions. It automatically constructs derivatives to other unknown variables (eg. "V(in)"), to be able to correctly load the Y-matrix and Rhs-vector each iteration. Still, there are some things it cannot do:

• Unsolvable circuits can occur. It becomes possible to bias circuits in impossible situations. For example, a component that does not dissipate power (but generates is), will cause the simulator to possibly throw cryptic exceptions as the circuit experiences a meltdown.
• Unstable circuits. Nonlinear devices are notorious when it comes to convergence or numerical stability. For example, an exponential curve is known to converge very slowly for diodes, so Spice# implements a number of "tricks" to aid convergence. Using this library means that these "tricks" are now also to the user to implement.

Please use the library with care.

Current build status

Platform	Status
Windows
Linux (Mono)
MacOS (Mono)

Aim of Spice#.Behavioral?

The aim is to provide an easier way of prototyping models in the Spice# simulator. While it is technically possible for anyone to extend Spice# with custom models and components to have full control over its behaviors, Spice#.Behavioral takes away a lot of that work.

Advantages:

• No prior knowledge needed about Newton-Raphson, Modified Nodal Analysis, etc.
• No need for calculating derivatives by hand for models.
• Changing models is likely easier and faster.

Disadvantages:

• General performance can be sub-optimal.
• It may be unclear for inexperienced users why a simulation became unstable or badly behaving.