A 3D-printed battery-free bike light: a magnet ring spun by eddy currents from the moving rim drives a hand-wound coil that lights an LED · 6 ステップ · 作成：William Kennedy (zumdar), with Lucas Ray…
テキストは CC BY-SA 4.0 でライセンス · 写真と引用の権利は所有者に帰属