PURPOSE: A reinforced coil is provided to improve the performance of system by serially connecting an inner coil and an outer coil in every turn. CONSTITUTION: A strengthening coil is applied to an electric motor or a generator. The strengthening coil is included of an outter coil and an inner coil. The outer coil and inner coil are wound around the air core and the magnetic material. The outer coil and inner coil are rotated in same direction. The number of turn in the inner coil is twice than that of outer coil. The inner coil is connected to outer coil at each turn.
