A coil of wire, or solenoid, consists of a wire coiled up into a spiral shape. When an electric current flows, the shape of the magnetic field is very similar to the field of a bar magnet.

A coil of wire, or solenoid, consists of a wire coiled up into a spiral shape. When an electric current flows, the shape of the magnetic field is very similar to the field of a bar magnet.

A recent study proposed a method using an array of TMR chips to detect the magnetic field around a current-carrying wire, demonstrating its practicality for real-time monitoring in power systems[1].