Toroidal coil

A toroidal coil is a wire wound around a donut‑shaped (toroid) magnetic core, designed to confine magnetic flux almost entirely within the core. The key takeaway: a toroidal coil provides high inductance, low electromagnetic interference (EMI), and efficient magnetic field confinement thanks to its closed-loop geometry. Common Applications: Power supplies (filter inductors, chokes) Transformers (mains, audio, isolation) RF circuits (tuned LC circuits) Energy storage in magnetic fields