Orthocyclic winding structure creates an optimal fill factor (90.7%) for round wires. The windings of the upper layer need to be placed into the grooves provided by the lower layer.
Rectangular magnet wire used in Orthocyclic winding
The best volume use is found when the winding is parallel to the coil flange for most of its circumference. When the winding has been placed around the coil body it will meet with the previous positioned wire and needs to make a step with the size of the wire gauge. This movement is called winding step. The winding step can occupy an area of up to 60 degrees of the coil circumference for round coil bobbins and takes one side of rectangular coil bobbins. The area of the winding step is dependent on the wire gauge and coil bobbin geometry.
If the winding step cannot be executed properly then the self-guiding ability of the wire is lost, and a wild winding is produced. Overall, the first intruding wire mainly determines the location and quality of the winding step. It should be recognized that the wire needs to enter in a possibly flat angle into the winding space. That way an unnecessary bending of the wire is being avoided and the needs space for the second winding step is minimized.
For Orthocyclic wound coils, the winding step areas is always located at the area of wire entering the winding space and is continued in helical form against the winding direction. Consequently, a larger winding width of the coil leads to a bigger winding step area along the circumference of the coil. The created offset leads to a different position of the layer step, from the first to the second layer, in comparison to the wire entry. This behavior repeats itself with every layer which leads to a spiral shaped crossover section at the side of the winding. When wires are crossing within the crossover section the resulting winding height is increased. As a result, Orthocyclic wound coils with a round coil ground are never circular in the cross over section, but the radial moving winding and layer step creates a hump shape. Experience has shown that depending on the winding width, coil and wire diameter, the crossover section is about 5 to 10 percent higher than the regular winding height.