大学电路理论课程教案-线性直流电路5

3.7叠加定理nnnnnnRRRRRRRRR212222111211nIII21nnEEE2211=回顾:网孔法解的形式:nnniiiiEEEI2221113.7叠加定理•对于有唯一解的线性电路,任一该支路电压或电流,是各独立源分别单独作用时在该支路形成的电压或电流的代数和。例：21+-+-10V2IXIX3A21+-+-10V2IXIX3A21+-2IX’IX’3A21+-+-10V2IX’’IX’’••IX’’=2(A)IX’’=-0.6(A)IX=IX’+IX’’=1.4(A)nnnnnnRRRRRRRRR212222111211nIII21nnEEE2211=解的形式:nnniiiiEEEI222111nnniiiiKEKEKEKI2221113.7齐次定理•对于有唯一解的线性电路,各独立源一致增大（或缩小）K倍，则任一该支路电压或电流,也相应地增大（或缩小）K倍。例：21+-+-10V2IXIX3A21+-+-30V2IXIX9A21+-+-10V2IXIX3AIX=1.43(A)IX=1.4(A)例3。10：+-7V1111111求：各支路电压和电流+-7VI2I3I1+-7V1111111解一：0.51111121V1A1V1A2A3V3A5A8V8A13A解二:解二:21V/31A/31V/31A/32A/33V/33A/35A/38V/38A/313A/33.8互易定理互易定理的证明见P65互易定理应用举例:R3R1I5R2R5R4Us+-求:I5•解:R3R1I5R2R5R4Us+-R3R1I5R2R5R4Us+注意参考方向R3R1I5R2R5R4Us++-I5R3R5R4R2R1UsII1I3)//()//(43215RRRRRUIS4343RRRII2121RRRII315III分流：KCL：