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.

Getting a magnetic field to ... of current regulation ICs. The coils can be made in house if necessary, with each winding getting about 800 turns of enameled wire. The rest of the circuit is ...