Method for winding a multi-layer flat wire coil

A method for winding a multi-layer flat wire coil, comprising the steps of:

• a) providing a wire supply;
• b) providing a winding core;
• c) providing an auxiliary winding core;
• d) winding wire from the wire supply onto the auxiliary winding core, wherein a length of wire wound onto the auxiliary winding core substantially equals a length of wire required for an odd layer of a pair of layers of the multi-layer flat wire coil;
• e) winding wire from the wire supply onto the winding core to form an even layer of the pair of layers of the multi-layer flat wire coil while keeping the even layer connected to the wire supply;
• f) winding wire from the auxiliary winding core onto the winding core to form the odd layer;
• g) providing a further winding core;
• h) mutually locking the auxiliary winding core and the winding core of the previously formed pair of layers;
• i) arranging the auxiliary winding core in between the winding core of the previously formed pair of layers and the further winding core;
• j) performing steps d)-f) to form a pair of layers onto the further winding core while keeping the auxiliary winding core and the winding core of the previously formed pair of layers locked;
• k) unlocking the auxiliary winding core and the winding core of the previously formed pair of layers;
• l) rotating the winding core and the further winding core relative to each other while moving them towards each other in an axial direction to tightly wind the remaining wire between the winding core and the further winding core around the winding core, the further winding core, or both.