About Inertance

Inertance is an independent educational project created by Lucas Wybrandt. It helps students, teachers and curious engineers explore circuit energy storage and switching power conversion through an interactive hydraulic analogy.

Pressure represents voltage, flow represents current, a flywheel represents inductance and a spring-loaded piston represents capacitance. The editable simulator displays the circuit and its waveforms on a shared timeline.

The simulator is free to use in a web browser. It is an early teaching tool with stated model limitations, rather than a replacement for engineering design validation. The project is not affiliated with any university or manufacturer.

Contact and source code

For questions, feedback or bug reports, open an issue in the public GitHub repository. Reports there are public; please avoid sharing personal information or confidential circuit files.

Privacy and browser data

Simulations run in your browser. Circuit and netlist files you open are read locally, and circuit downloads are created locally. The simulator contains no circuit-upload service, account system or advertising.

The app saves display and playback preferences in your browser’s local storage. You can remove these by clearing this site’s browser data.

Optional usage analytics helps Lucas Wybrandt understand visits and which features people use. It contacts Umami Cloud only after you allow it. The analytics website uses Umami’s EU data region and the free plan’s six-month retention. Umami is a US-based provider; choosing an EU region does not mean all processing is exclusively within the EU.

We send only the site hostname, the page path (/app/ or /about/) and fixed action names: starting a simulation, choosing a built-in preset or model mode, editing a circuit, arranging or resetting a view, import preview/apply outcomes and JSON copy/download actions. We never send circuit contents, component values, filenames, pasted text, error messages, URL queries or hashes, referrers, or personal identifiers. The redirect page and older demo have no analytics.

Umami receives your IP address and browser’s User-Agent with normal network requests and uses them to estimate visits, devices and location. Visitor numbers are approximate. We do not store analytics cookies or visitor IDs in your browser, use session replay, or save identifiers returned by Umami. The dashboard is private. Your allow/decline choice is saved in local storage for 180 days, separately on each domain. Do Not Track and Global Privacy Control keep analytics off. Declining does not affect the simulator.

lets you withdraw consent at any time. This stops future analytics requests; it cannot recall requests already received by Umami. For questions about data handling, contact Lucas through the public repository linked above without posting private circuit files.

GitHub Pages hosts the site and receives normal web requests. See GitHub’s privacy statement for its handling of visitor data. The older buck demo requests fonts from Google Fonts. The simulator’s d3 chart library is served from this website.

For teachers and site reviewers

The site’s purpose is education in electronics and electrical circuits. It offers interactive browser simulations, editable examples and waveform explanations. The canonical address is https://inertance.org/; the working app is at /app/.