我根據(jù)成都啟達科技有限公司陳先生寫的<<反激式變壓器計算>>.
然后自己照著計算,我把它寫下來.請電源論壇的同志們幫我看看
錯在那里.好讓我盡快入門.在此謝謝各位!
我的電源要求如下:
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Vin=8-18V(DC)
Vout=85V@0.45A
F=100khz
Duty=0.5
η>85%(不知道如何確定)
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計算過程:
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setup1:選擇CORE材質,確定△B.
PC44(TDK)
△B=0.2T
setup2:
確定CORE SIZE TYPE.
PQ2020
setup3:
估算IOB
IOB=0.8X0.45A=0.36A
setup4:
求匝數(shù)比N.
N={Vin(min)/(Vo+Vf)}x{Dmax/(1-Dmax)}
=8/(85+0.6)x0.5/0.5
=0.09
≒0.1
setup5:
求CCM/DCM臨界值.
△ISB=2IOB/(1-Dmax)
=2x0.36/0.5
=1.47A
setup6:
計算LS LP
LS=(VO+VF)(1-Dmax)xTs/△ISB
=85.6x0.5x(1-100000KHZ)/1.47
=2.85uH
LP=n2XLS
=0.285uH
setup7:
求CCM時幅邊的峰值電流.
△isp=Io(max) / (1-Dmax) + (ΔISB/2)
=1.65A
setup8:
求CCM時原邊峰值電流.
△ipp=△isp/n
=16.5A
setup9:
確定Np、Ns
Np = Lp * ΔIpp / (ΔB* Ae)
=0.0285x16.5/0.2x62
=0.0379
Ns=np/n
=0.379
Step10 計算AIR GAP
lg = Np2*μo*Ae / Lp
;算不下去了.