图示电路中,已知:US1 = 24V,US2 = 6V,IS =10A,R1 = 3 ,R2 = R3 = R4 = 2 .用戴维宁定理求电流I .

问题描述:

图示电路中,已知:US1 = 24V,US2 = 6V,IS =10A,R1 = 3 ,R2 = R3 = R4 = 2 .用戴维宁定理求电流I .

先将R4两端断开,电流源开路,电压源短路,求出R4两端的等效电阻Req=R1//R2+R3=1.2+2=3.2Ω
然后求两端的等效电压,R4断开,最右边用KVL求出两端电压U=(Us1-Us2)*R2/(R1+R2)+Us2=13.2V
Ueq=13.2+Is*R3=33.2V
I=Ueq/(Req+R4)=6.15A