An interactive electromagnetic induction workbench built with React, TypeScript and Three.js. Move a magnet through a coil and watch the field illustration, galvanometer, measurements and graphs respond to one deterministic teaching model.
Watch / download the demo — 40 seconds, 30 fps, MP4 · Recording method · 中文简介
The video captures the actual application with scripted inputs and a fixed simulation clock. Each of its 1,200 frames was rendered and captured separately; no frame interpolation, generated video or fake instrument readings. The application itself is fully interactive.
Requires Node.js 22.12 or newer and npm.
git clone https://github.com/JesseQin123/induction-bench.git
cd induction-bench
npm ci
npm run devOpen http://127.0.0.1:5178/. No account, API key or backend is needed. Fonts are bundled locally; after installing dependencies, the application works without external network requests. .npmrc retains the peer-dependency installation mode used by the lockfile.
npm test # numerical model and deterministic replay checks
npm run build # TypeScript checks and production bundle
npm run preview # serve dist at http://127.0.0.1:4178/If a port is busy, use npm run dev -- --port 5180. Serve the production dist/ folder over HTTP; opening its HTML directly as a file will not load module assets correctly.
- Drag the 3D magnet, use the position slider, or start Swing magnet. Motion follows the selected speed limit instead of teleporting.
- Flip the poles; select N52, N42, SmCo or ferrite; compare copper, silver, aluminium and nichrome windings.
- Adjust 50–400 turns, 0–180° coil angle, air / soft-iron core and a −12 to +12 V battery.
- Orbit, zoom, or choose one of four camera presets. Pause, reset, hide field lines or reduce decorative motion.
- Read induced EMF, total current, estimated central field and force. The scope plots induced voltage/current; the flux plot shows the same model's linkage and tangent.
- Export the last eight simulation seconds to CSV: up to 240 samples, 30 Hz, SI units.
- Tab to controls and use arrow keys on sliders. With the 3D scene focused, ← / → moves the magnet, Space pauses and R resets. The information dialog closes with Escape. Phone and tablet layouts rearrange the instrument panels.
Use the 40-second guided demo link in the footer to replay the video sequence live. Clicking an experiment control, or using its keyboard controls, returns to normal interaction.
This is a simplified, quasi-static educational model, not a real engineering field solver. src/model.ts owns all numerical results. The simulation uses a fixed 1/120-second step and samples its graphs at 30 Hz.
For pole sign s, turns N, remanence Br, core factor k (air: 1; iron: 3), angle θ and position x in metres:
Λ(x) = s N Br (7 × 10⁻⁶) k cos(θ) / [1 + (x/0.038)²]^(3/2)
∂Λ/∂x = Λ(x) × −3x / (0.038² + x²)
EMF = −(∂Λ/∂x) v
I = (Vbattery + EMF) / (Rwire + 1 Ω)
F = I × (∂Λ/∂x)
Wire resistance uses resistivity, estimated winding length and cross-sectional area. The analog meter saturates at ±2 A with an explicit over-range label; the digital reading remains available. Scope channels have independent labeled scales. The total-current meter includes the battery; the scope's induced-current trace does not.
The coupling envelope is selected for clear teaching, not fitted to a measured magnet. Motion is prescribed; the displayed force does not accelerate it. Parameter edits are quasi-static and do not produce parameter-change transients. There is no RL transient solution, heating, hysteresis, saturation, skin effect or eddy-current simulation. Inductance is a static estimate. Field lines are procedural illustrations, not integrated streamlines of a solved combined field. Visible winding loops represent groups of physical turns; 3D dimensions are exaggerated for readability.
Inspired by The Bugged Dev's Induction bench, featured in Claude's showcase and project collection. Reference frames were inspected to guide the instrument-panel composition. This is an independent implementation with original application code and procedural geometry; the reference screenshots, video and original application assets are not distributed here.
This project is not affiliated with, authorized by, or endorsed by The Bugged Dev, Anthropic or Claude. It does not claim pixel-perfect equivalence or the original application's internal physics. See reference differences.
Original code, documentation and recordings of this implementation are available under MIT. Bundled Barlow fonts retain their SIL Open Font License. Dependencies retain their own licenses; see third-party notices.
一个可实际操作的电磁感应实验台：拖动或摆动磁铁，观察电表、感应电压、电流、磁通与示波器同步变化。支持磁极翻转、四种磁铁和导线、匝数、线圈角度、铁芯、电池、CSV 导出、键盘操作及减少动效。
按上方命令安装并启动，打开 http://127.0.0.1:5178/。页脚的 40-second guided demo 可在网页中重放演示；点击任一实验控件即可接管操作。视频为 40 秒、30 fps 的真实网页逐帧采集，使用确定性脚本输入，不是旧视频插帧或生成式视频。
这是简化的准静态教学模型，不是工程电磁求解器。实现受 The Bugged Dev 的演示启发，代码与几何独立编写，不代表原作者授权或官方合作。项目采用 MIT 许可证，字体另遵循 OFL。