Current transformer is an electronic component that can convert electrical energy into magnetic energy, store it under appropriate conditions, and release it and then convert it into electrical energy. The most important role of inductor is electromagnetic conversion.

All electrical conductors (transmission lines) will cause electromagnetic fields when passing current. When the electrical conductors (transmission lines) are wound into a spiral shape, the electromagnetic field will be concentrated, and the more the number of turns, the more the magnetic induction intensity. The larger the size, the greater the kinetic energy, so the inductor is actually an electrical conductor (transmission line) wound into a spiral.