Detailed explanation of RCC design method

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Detailed explanation of RCC design method [Copy link]

In RCC design, the operating frequency is generally set first, such as 50K, and then the operating DUTY is set at 90V input, and the maximum output is 0.5.
Assume that the design power is 12V/1A
1. The maximum output current is 1.2~1.4 of the rated current. times, take 1.3 times.
2. Output power Pout = Vout × Iout = 12V×1.3A = 15.6W
3. Input power Pin = Pout/∩=22.3W (RCC efficiency ∩ is generally set at 65%~75%, take 70 %)
4. Input average current Iin=Pin/Vdc(INmin)=22.3/85*1.2=0.22(Vin(DCmin) = Vac(Inmin)×1.2)
5. T=1/swF=1/50K=20uS Ton =Toff =10uS
6. Ipk=Iin input average current*2/DUTY=0.22*2/0.5=0.88
7. Primary side inductance Lp=Vin(DCmin)*Ton/Ipk=102*10/0.88=1159uH, take 1160uH
8. Select the magnetic core. According to the core specifications, choose EI28. Ae=0.85CM^2 Operating magnetic flux = 2000~2800, take 2000 (of course, this is a very conservative approach)
9. Np=Ipk*Lp*K/Ae *▲ Bm=(0.88*1160*100)/(0.85*2000)=60Ts
10. Ns=(Vout+Vf)*Np/Vin(DCmin)=7.6 Take 8Ts
11. The auxiliary voltage takes 5V (transistor) such as If the power tube uses MOSFET, it should be set to 11V
12. Vin(DCmin)/Np=Vb/Nb----Nb=2.94 Take 3Ts,
so the structure of the transformer is as follows:
Lp=1160uH
Np=60Ts
Ns=7Ts
Nb=3Ts
uses sandwich Winding method. Above