R_andy:
好版:我重新算了下、输入85-265Vac,输出20V/350mA,效率83%,MOS耐压650,输出整流二极管400V。F=50KHz.1.我先确定占空比0.4,CCM模式!2.VF=100*0.4/0.6=67V3.Ip1+Ip2=7w*2/(83%*100*0.4)=14/33.2 设Ip2=2.5Ip1 得到Ip1=0.12A Ip2=0.3A4.Lp=Vinmin*Dmax/(F*Ip)=100*0.4/(50*1000*0.18)=4.4mH5.匝比n=Np/Ns=Vinmin*Dmax/((Vout+Vd)*(1-Dmax)) =100*0.4/((20+1)*0.6)=3.17=3.26.我用EFD15的磁芯,Ae=15mm^2NP=LP*(Ip2-Ip1)/(Ae*Bm)=4.4*1000*0.18/(15*Bm=0.18)=300Ts次级为100Ts。这样完全饶不下啊!好版帮忙看看哪有问题的。谢谢!