Low profile transformer

A low-profile transformer, comprising:

• a core unit having a pair of opposingly arranged base portions, an inserting portion, and a pair of opposingly arranged lateral portions,
• wherein the inserting portion has a long axis, the inserting portion and the lateral portion extend from the base portion substantially along the long axis,
• wherein the top-facing edge of the lateral portions is chamfered,
• wherein the lateral portion is spaced from the inserting portion, defining a pair of coil winding space there-between for passing coils;
• and
• at least a primary coil and a secondary coil wound around the inserting portion,
• wherein the primary coil has a primary coil winding number (Np) while the secondary coil has a secondary coil winding number (Ns), the ratio of Np and Ns defines a coil winding ratio (N),
• wherein the Np and N selectively satisfy the solution space of a characteristic effective area function Ae(Np, N) and a characteristic magnetic flux variation function ΔB(Np, N), which are provided by applying predetermined operational and material specifications to a characteristic equation:
• A
• e
• =
• V
• in_min
• ⁢
• D
• ⁡
• (
• V
• in_min
• ,
• N
• ,
• V
• o
• )
• N
• p
• ⁢
• Δ
• ⁢
• ⁢
• B
• ·
• fre
• wherein
• Ae denotes an effective cross-sectional area of an inserting portion,
• Vin—min denotes minimum AC (alternating current) input voltage in [V],
• N denotes winding ratio between primary and secondary windings,
• Vo denotes DC output voltage in [V],
• D (Vin—min, N, Vo) denotes duty cycle, wherein
• D
• 1
• -
• D
• =
• N
• ⁢
• V
• 0
• V
• in_min
• ,
• Np denotes primary winding number,
• ΔB denotes change in magnetic flux density in [Tesla],
• fre denotes operating frequency in [KHz].