Transformers including secondary winding turns having different diameters

1. A transformer comprising:

a transformer core;

a primary winding wound about the transformer core, the primary winding including a wire wound in multiple primary winding layers, and each primary winding layer including multiple primary turns arranged in a spiral; and

a secondary winding wound about the transformer core, the secondary winding including one or more substantially flat conductors defining multiple secondary winding layers, each secondary winding layer including one secondary turn, every two adjacent secondary turns having a single different one of the primary winding layers positioned between the two adjacent secondary turns to interleave the secondary winding and the primary winding, and each secondary turn having a different diameter than an adjacent one of the secondary turns.

2. The transformer of claim 1 , wherein:

the wire is arranged to transition between a first and a second of the multiple primary winding layers at innermost turns of the first and second primary winding layers; and

the wire is arranged to transition between the second and a third of the multiple primary winding layers at outermost turns of the second and third primary winding layers.

3. The transformer of claim 2 , wherein:

the wire is arranged to transition between the first and second primary winding layers along an inner portion of a first one of the secondary turns;

the wire is arranged to transition between the second and third primary winding layers along an outer portion of a second one of the secondary turns; and

the first and second ones of the secondary turns are adjacent one another.

4. The transformer of claim 3 , wherein:

a diameter of the outer portion of the first one of the secondary turns corresponds to a diameter of a core window of the transformer; and

a diameter of the inner portion of the second one of the secondary turns corresponds to a diameter of the transformer core.

5. The transformer of claim 1 , wherein the one or more substantially flat conductors of the secondary winding include at least three substantially flat conductors arranged in parallel.

6. The transformer of claim 1 , wherein each substantially flat conductor includes at least two turns.

7. The transformer of claim 1 , wherein the multiple primary winding layers include at least three primary winding layers.

8. The transformer of claim 1 , wherein each primary winding layer includes at least four primary turns.

9. The transformer of claim 1 , wherein a ratio of the number of primary turns to the number of secondary turns is at least five to one.

10. The transformer of claim 1 , wherein the wire comprises a continuous wire defining the multiple primary winding layers.

11. The transformer of claim 1 , wherein the substantially flat conductor includes a continuous substantially flat conductor defining multiple ones of the secondary turns.

12. The transformer of claim 1 , wherein the substantially flat conductor includes an enamel insulation coating.

13. The transformer of claim 1 , wherein each substantially flat conductor comprises a single piece of pre-coated flat conductor material.

14. A transformer comprising:

a transformer core;

a primary winding wound about the transformer core, the primary winding including a wire wound in multiple primary winding layers, and each primary winding layer including multiple primary turns arranged in a spiral; and

a secondary winding wound about the transformer core, the secondary winding including a substantially flat conductor defining at least three secondary turns, every two adjacent secondary turns having a single different one of the primary winding layers positioned between the two adjacent secondary turns to interleave the secondary winding and the primary winding, and a transition portion between first and second ones of the secondary turns offset from a transition portion between second and third ones of the secondary turns to avoid an overlap between the transition portions.

15. The transformer of claim 14 , wherein each transition portion includes a bend in the substantially flat conductor.

16. The transformer of claim 14 , wherein adjacent ones of the at least three secondary turns have different diameters.

17. The transformer of claim 14 , wherein:

the wire transitions between a first and a second of the multiple primary winding layers at innermost turns of the first and second primary winding layers; and

the wire transitions between the second and a third of the multiple primary winding layers at outermost turns of the second and third primary winding layers.

18. The transformer of claim 17 , wherein:

the wire transitions between the first and second primary winding layers along an inner portion of a first one of the secondary turns;

the wire transitions between the second and third primary winding layers along an outer portion of a second one of the secondary turns; and

the first and second ones of the secondary turns are adjacent one another.

19. The transformer of any one of claim 14 , wherein the substantially flat conductor includes a continuous substantially flat conductor defining the at least three secondary turns.

20. The transformer of claim 1 , wherein the substantially flat conductor comprises a single piece of pre-coated flat conductor material.

21. The transformer of claim 18 , wherein:

a diameter of the outer portion of the first one of the secondary turns corresponds to a diameter of a core window of the transformer; and

a diameter of the inner portion of the second one of the secondary turns corresponds to a diameter of the transformer core.

22. The transformer of claim 1 , wherein the wire includes an insulation coating.

23. The transformer of claim 14 , wherein the substantially flat conductor includes an enamel insulation coating.