Working with input files

Everything you type into Symbulator — circuit, analysis, settings, the Evaluate and Solve cards — can be saved and reused. Two words matter here.

• An entry is one named set of inputs: a circuit, the analysis to run on it, and the settings.

• An input file is a named collection of entries, such as Circuits for Lesson 1 of the Tutorial.

Input files are plain text with the extension .cir. They are optional. The buttons to load, download and create them are in the Input File card at the top of the app.

Loading input files

Symbulator comes with an input file for each lesson of this tutorial, holding an entry for every simulation in it. A problem that takes more than one simulation has an entry for each, so a lesson file may hold more entries than the lesson has problems. With them you can follow the whole tutorial without typing a circuit.

Built-in examples lists them; click a title to load it. These files are read-only: change a loaded one as much as you like, but you cannot write back to it.

To open your own input file, click Upload and choose the .cir file. The dropdown beneath then reads Entries in and the file's name. Choosing an entry fills in every box on the page. Solve it as if you had just typed it.

Saving an entry while a read-only file is loaded, or clicking Create new, starts a blank input file of your own.

Saving your work

Two links under the circuit box appear when they apply:

• Save inputs to new entry adds what is on screen as a new entry and asks for a name.
• Update inputs in this entry writes your changes back into the loaded entry. It appears once you have changed something.

Beside the dropdown, Rename and Delete act on the entry itself. Neither is offered for the built-in examples, since they are read-only.

What an entry remembers

An entry keeps everything you typed, not just the circuit: the analysis and what it needs (the frequency, the nodes of an equivalent, the kind of two-port), the Expert Mode equations, unknowns and conditions, everything in Settings, Evaluate and its Conditions, the Solve card, the Plotting Tools inputs, and a note of your own shown when the entry is loaded. Load one a year later and you are back where you left off.

The About input file (.cir) format section inside the Input File card explains what input files carry, in detail.