经典：反激变压器设计公式.xls

FORWARD DISCONTINUE MODE BOUNDARY AT VINMIN Item unit VALUE Formula 聶建華 2017 -3-5 Vinmin Vac ##### Vinmax Vac ##### VHP Vdc VLP Vdc Vo Vdc Iomax A Iomin A Vd(diode) Vdc Freq MHz Output power W Eff % % Dmax Ap estimated mm^4 21853 4000*Po/f* Aw mm^2 EER3335S Ae(xf) mm^2 Ap selected mm^4 19680 delta B(xf) Ae(choke) mm^2 gap(choke) mm XFORMER Vsmin Vdc (Vo+Vd)/Dmax n(Np/Ns) VLP/Vsmin Vsmax Vdc VHP/n Np turn VLP*Dmax/(deltaB*f*Ae(xf)) Ns turn Np/n Ns selected Np selected #### Dmax (Vo+Vd)*n/Vlp Lmin uH 3892 (VLPn*Dmax)^2/(2*f*Vo*Iomax*) Lg (xf) mm 4*PI()*Ae*N^2* Irms A =Pin/(Vlp*) CHOKE Dmin (Vo+Vd)/Vsmax delta Imax A 2*Iomin Ipeak A Iomax+*deltaImax L uH (Vsmax - Vo - Vd)*Dmin/(f*deltaI) ENG J 8218 1/2*L*Ipeak^2 AP cm^4 2*W*100/K/B/$ N Turn (L(choke)*gap/(4*PI()**Ae(choke))^ N selected Turn N L selected uH 4*PI()*Ae*N^2* Bmax T L(choke)*Ipeak/N/Ae(choke) Output ripple mV Output E- cap uF ( Vo+Vd)*(1 - Dmax)/(8*L*delta V*fs^2)*1000 C= S (Ipeak - Io) d T/ripple (Ton/2~Toff/2) Because output E- cap be charged @ Ton/2 to Toff/M BOOST TRANSFORMER DESIGN 聶建華 2017 -3-5 Input ac line Vac V Input voltage Vin V Output voltage Vout V Duty