(1) Transformer silicon steel sheet cross section: 3.2CM*3.4CM*0.9=9.792CM^2
(2) Calculate transformer power based on silicon steel sheet cross section: P=S/K^2=(9.79/1.25)^2=61.34 watts (take 60 watts)
(3) Calculate the number of turns per volt of the coil based on the cross section: W=4.5*10^5/BmS=4.5*10^5/(10000*9.79)=4.6 turns/volt
(4) Number of turns of the primary coil: 220*4.6＝1012 turns
( 5) Primary coil current: 60W/220V=0.273A
(6) Primary coil wire diameter: d=0.715 root 0.273=0.37(MM)
(7) Secondary coil turns: 2*(51*4.6*1.03)=2*242(turns)
(1.03 is the step-down factor, two-stage 51V=2*242 turns)
(8) Secondary coil current: 60W/(2*51V)=0.59A
(9) Secondary wire diameter: d=0.715 root 0.59=0.55(MM)
