Circuit Simulator is renamed CircuitJS1 Desktop Mod
The source code for offline version of the Circuit Simulator with minor modifications based on modified NW.js. It was originally written by Paul Falstad as a Java Applet. It was adapted by Iain Sharp to run in the browser using GWT. The program was modified and compiled to offline version for Windows (x32, x64), Linux (x32, x64) and MacOS (x64, arm64) by Usevalad Khatkevich.
This program is distributed by me as a program for education. It is not recommended to use the program for modeling real circuits, since many components in the program are idealized.
The program supports the following languages: English, Russian, Danish, German, Polish, Spanish, French, Italian, Portuguese, Czech, Norwegian, Chinese, Japanese.
For a web version of the application see:
Paul's Page: https://www.falstad.com/circuit/
Source code: https://github.com/pfalstad/circuitjs1
Iain's Page: https://lushprojects.com/circuitjs/
Source code: https://github.com/sharpie7/circuitjs1
You can download this program for Windows (x32, x64), Linux (x32, x64) and Mac OS X (x64, arm64):
If you have problems with this application, you can try to use this offline application of the main developer based on Electron.
The tools you will need to build the project are:
- JDK 17+
- Maven 3+
- Node.js with npm
Install the dependencies in the local node_modules folder:
npm install
For desktop packaging (currently builds a Linux x64 release by default):
npm run build
For a full rebuild with complete cleanup (then package a Linux x64 release):
npm run full
Output folder: ./out/
Also you can build only the GWT application:
npm run buildgwt
and run it in NW.js SDK version:
npm start
npm start launches NW.js in detached mode (the terminal command returns immediately).
Output folder: ./target/site/
Various build options, checker and devmod are available in the development menu:
npm run dev
Separate commands:
Check the build steps:
npm run check
Run devmode:
npm run devmode
Devmode works directly in the war directory separate from the target/site directory.
The built-in/standard example circuits (the files served under /circuits/... in the web UI/devmode) are stored in:
src/main/java/com/lushprojects/circuitjs1/public/circuits
These circuits are a convenient baseline corpus for testing (manual checks and automated import/export roundtrips).
Note: npm run devmode starts mvn gwt:devmode and also tries to launch NW.js for the dev UI; it is a long-running process.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
© Usevalad Khatkevich 2025
- Paul Falstad - Creator
- Iain Sharp - JavaScript conversion, so there are more opportunities for the development of this application.
- Brian Gordon - Mavenized version of circuitjs1