Inductive power transfer coil and method for making the same for use in wireless power transfer systems

A method of manufacturing an inductive power transfer (IPT) coil, the method comprising:

• providing a coil scaffold comprising an elongate member arranged in a helical form about a looped path with the looped path providing the axis of the helical form, wherein each circuit of the looped path by the elongate member provides a coil turn and wherein the coil scaffold comprises at least a first coil turn and a second coil turn of a series of coil turns, wherein the second coil turn is successive to the first coil turn in the series of coil turns, wherein the helical form has a pitch selected so that each coil turn of the elongate member comprises less than one complete helix turn of the elongate member, and wherein, for each coil turn, the start is radially offset from the end, thereby to provide the first coil turn and the second coil turn as being non-coplanar with each other and with the first coil turn is at least partially surrounded, radially, by the second coil turn;
• and
• providing a conductive layer which conforms to and covers the surface of the elongate member to provide a conductive tube which follows the form of the scaffold to provide the coil;
• wherein the coil scaffold supports the conductive tube so that there is a spacing between the first coil turn and the second coil turn.