开关电源变压器的计算

一，变压器（1）选磁性材料PC40(100℃，Bs=0.39T，Br=0.055T)取B=0.2T（2）磁芯型号AP=1.14311.1()'pinkBf=1.143411.160()0.3610.950.1140.275103cmAP’=441.281.081.380.36cmcm选EE40（3）计算原边绕组匝数令Dmax=0.45则Ton（max）=DmaxT=630.45610(7510)minmaxPPBBVinNAeNAeTTonminmax43410.459.61.28100.27510PVinTonNAeB取PN=10匝（4）计算副边绕组的匝数minmaxmax()()(1)sfwdoOfwdpNVinVVDTVVDTNminmax121107.046410.45ofwdspVVNNVinD取sN=7匝（5）计算原边电流有效值max2max01()0.750.452.3479DTsosprmsOppNINIdtIDATNN22.34790.52184.5prmspIAmmj440.52180.8153.14pAD考虑到集肤效应750.273mmf20.546D20.815()3.010.47取原边为0.47mm的4股并绕（6）计算副边线径max2max01()50.453.354DTsrmsoOIIdtIDAT40.974sAD考虑到集肤效应20.974()4.290.47所以取副边为0.47mm的漆包线五股并绕（7）计算电感的阈值，线径与匝数令10%0.5oconIIA()11(1)22OfwdoclVVIiDTLmin()(1)()(1)22OfwdOfwdococVVDTVVDTLIImaxminmin()()(1)sfwdOofwdpNVinVVDTVVDTNminmax121100.326577pofwdBVVDNVinN3(121)(10.326)11720.157510LH5.5LpkocoIIIA选取pc40磁性材料（100℃Bs=0.39TUr=230）241.1434410()0.4784500.60.25ppkLIAPcmcm选EE4041.281.081.380.478APcm645.51171020.111.28100.25lpkLEmLINAB取21匝5LrmsnIIA51.1114.5LA41.1111.189LD21.189()3.140.67取电感线径为0.67mm4股并绕（8）驱动变压器的计算11()(1)mmmVDTVVDT1(1)mmVDV取mV=16v得1(min)(10.45)168.8mVV131.58.8SpNN原边30匝，副边45匝用EE25线径为0.21mm