lb5984：
最后更換了個DEMO板的變壓器上去,就沒有任何問題了.電路輸入輸出要求如下:Input:~90-240V50HzOutput:+/-14V1.0A+5V1.2A-27V0.05AAC3.6V0.05A(+/-14V是功放電源,要求與+5V不能共地).哪位大蝦指導一下我算的參數(shù)有什么不對的地方:Po=(14+14)x1.0+5x1.2+27x0.05+3.6x0.05=35.53WPin=35.53/0.8=44.41WVin(min)=AC90x1.414=DC127VVin(max)=AC240x1.414=DC340VIin(min)=Pin/Vin(max)=44.41/340=DC0.13AIin(max)=Pin/Vin(min)=44.41/127=DC0.35AIpk=5.5Po/Vin(min)=5.5x35.53/127=1.54AEE2825,Ae=86.90mm^2,Al=3150nH(100T,1KHz0.25V,NOalr-gap):Lpr=Vin(min)xDmax/Ipkxf=127x0.5/1.54x50x10^3=0.825x10^-3H=825uHLgap=0.4πxLprxIpkx10^8/AeBmax^2Npri=(Lpri/AL)^0.5Npri取60TN5v=Nprix(5v+Vd)x(1-Dmax)/Vin(min)xDmax=2.69T 取3TNa=(Vcc+Vf)/(V5v+Vf1)xNs1=(16+1.7)/5.7x3=9.3,取9TN14v=(14v+1.0)x3/(5v+0.7)=7.89T取8TN27v=(27v+1.7)x3/(5v+0.7)=15.10取15TNvf=(3.6v+1.7)x3/(5v+0.7)=2.78取3T以上參數(shù)都是根據(jù)公式計算的,不知道那個地方?jīng)]注意到.請各位大蝦賜教賜教!!