5. Appendice

Here are some useful results for sizing forward transformers.

• Equal volumes of primary and secondary windings

  Since n ₂ = mn ₁ , the length of the secondary winding is m times that of the primary winding, assuming that the primary and secondary turns have the same length.

  If we adopt the same current density in the various windings, the wire cross-section of the secondary winding is 1/m times that of the primary.

  The copper volume of the secondary winding is therefore equal to that of the primary; the total volume of the windings is double that of the primary (triple in the case of a three-winding forward transformer, if we adopt the two-wire-in-hand winding for the primary...