— Transformer Sizing
Turns ratio and rated winding currents from a = Vp/Vs = Np/Ns, plus a core size estimate via the area-product method, Ap = (VA×10⁴)/(Kf·Bmax·J·f·Ku). The area product combines core cross-section and window area — the defaults shown (Kf=4.44 for a sine wave, Bmax=1.5 T for grain-oriented silicon steel, J=300 A/cm² natural convection, Ku=0.4 typical window fill) are common starting points; adjust them for your actual core material and cooling.