初級峰值電流計算公式?
輸入電壓vi:90-264V
輸出電壓vo:24V/2A
Vcc電壓:12V/0.5A
效率:?=80%
F:80khz D=0.45
最低DC電壓:90*1.1413-20=100VDC 264*1.1413-20=350VDC
輸出功率PO:24+1*2=50W
輸入總功率P:50/0.8=62.5W
根據(jù)輸入總功率選定磁芯:此處選PQ2620 Ae=119 最大磁通密度B max=0.2T
初級匝數(shù)NP=VDC*D/(Bmax*Ae*F)=100*0.45/(0.2*119*10^6*80*10^3)=23.6T
初級峰值電流IPK=2*PO/(VDC*D*?)=2*50/(100*0.45*0.8)=2.778A
初級電感LP=VDC*D*10^3/IPK*10^6=100*0.45*10^3/(2.778*10^6)=160UH
氣隙Ig=uo*NP^2*Ae/LP=0.4*3.1413*10^6*119*23.6^2/0.16=0.52mm
次級匝數(shù)NS=vo+VF*NP/Fv=24+1*23.6/85=6.94=7T Fv為折射電壓
Vcc=12+1*23.6/85=3.6=4T