大学电路理论课程教案线性直流电路9

3.14 双口网络互联 1、级联Na+i1a+i2au2au1aNb+i1b+i2bu1bu2bNa+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u1+u2i2i1 Na+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u1+u2i2i122211211AAAA=11iu22iuaaaaAAAA22211211=11iuaaiu22aaiu11=aaaaAAAA22211211bbiu11=aaaaAAAA22211211=bbbbAAAA22211211bbiu22aaaaAAAA22211211=bbbbAAAA2221121122iu aaaaAAAA22211211=bbbbAAAA2221121122iu11iuaaaaAAAA22211211=bbbbAAAA2221121122211211AAAA 2、串联Na+i1a+i2au2au1aNb+i1b+i2bu1bu2bNa+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u2+u1i1i2 Na+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u2+u1i1i221ii21uu22211211RRRR=aauu21+bbuu2121uuaaii21aaaaRRRR22211211=+bbii21bbbbRRRR22211211aaaaRRRR22211211=+21iibbbbRRRR22211211aaaaRRRR22211211=+bbbbRRRR2221121122211211RRRR 3、并联Na+i1a+i2au2au1aNb+i1b+i2bu1bu2bNa+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u2+u1i1i2 Na+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u2+u1i1i221uu22211211GGGG=21ii21ii=aaii21+bbii21aauu21aaaaGGGG22211211=+bbuu21bbbbGGGG22211211aaaaGGGG22211211=+21uubbbbGGGG22211211aaaaGGGG22211211=+bbbbGGGG2221121122211211GGGG 4、混联Na+i1a+i2au2au1aNb+i1b+i2bu1bu2bNa+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u2+u1i1i2 Na+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u2+u1i1i221ui22211211HHHH=21iu21iu=aaiu21+bbiu21aaui21aaaaHHHH22211211=+bbui21bbbbHHHH22211211aaaaHHHH22211211=+21uibbbbHHHH22211211aaaaHHHH22211211=+bbbbHHHH2221121122211211HHHH 例：+iki312+iki312 +iki3122003i2+u1+u22iikiuu21=203k2ii21uu=11111111203k3114k=+分别求R参数，再相加 5、与电源和负载的联接N+u1i1+u2i2RS+-uSRL输入端口输出端口电源 uS及内阻RS负载 RL有载双口网络有载不含独立源双口网络 N+u1i1+u2i2RS+-uSRL1）、输入电阻 R iN+u1i1+u2i2RLR i2）、输出电阻 N+u1i1+u2i2RS+-uSRL+u2-UOC i2RO+- N+u1i1+u2i2RS+-uSRL3）、电压传输比 u2 / u 14）、电流传输比 i2 / i12）、输出电阻 R O N+u1i1+u2i2RS+-uSRL3）、电压传输比 u2 / u 14）、电流传输比 i2 / i1例：已知：N的A参数， uS , RS , RL求：1）、输入电阻 N+u1i1+u2i2RS+-uSRL求： 1）、输入电阻Ri)(2122111iAuAu)(2222211iAuAiLRiu22代入2221121111ARAARAiuRLLi)()(2122111iARiAuL)()(2222211iARiAiL N+u1i1+u2i2RS+-uS求：1）、输出电阻Ro)(2122111iAuAu)(2222211iAuAissRiuu11代入1121ARAuussoc+uococuAu111ocuAi211socsocRuAuuA2111 N+u1i1+u2i2RS+-uS求：2）、输出电阻Ro)(2122111iAuAu)(2222211iAuAissRiuu11代入1222ARAuisssc+iscsciAu121sciAi221sscsscRiAuiA2212= 0 11211222ARAARAiuRssscoco1222ARAuisssc1121ARAuussocN+u1i1+u2i2RS+-uSRL+u2-uOC i2RO+- N+u1i1+u2i2RS+-uS求：3）、电压传输比 u2 / u 1)(2122111iAuAu)(2222211iAuAi代入121112ARARuuLLRLLRuAuAu2122111LRiu22LRui22 N+u1i1+u2i2RS+-uS求：4）、电流传输比 i2 / i 1)(2122111iAuAu)(2222211iAuAi代入2221121ARAiiLRL)()(2222211iARiAiLLRiu222）、输出电阻 R O N+u1i1+u2i2RS+-uSRL3）、电压传输比 u2 / u 14）、电流传输比 i2 / i1例：已知：N的H参数， uS , RS , RL求：1）、输入电阻 +u2RS+-uSRL求： 1）、输入电阻Ri2121111uHiHu代入LiGHHHHiuR2221121111+u1i1H12 u2H11+-H21 i1 i2H22LGHiHu2212121222112111)(iGHHHiHL +u2RS+-uS =0求： 2）、输出电阻Ro2221212uHiHi代入SoRHHHHiuR11211222221+u1i1H12 u2H11+-H21 i1 i2H22SRHuHi1121212222111221)(uHuRHHHS +u2RS+-uSRL求： 3）、电压传输比 u2 / u 12121111uHiHu代入11211222112112)(HRHHHHRHuuLL+u1i1H12 u2H11+-H21 i1 i2H22LGHiHu2212122122212211)(uHuHGHHL221221uHGHiL几种典型的双口网络（p31） 1、理想变压器N+i1+i2u1u21）定义：A参数：nn1002）性质：22211211AAAA=11iu22iu=11iu22iunn100 =11iu22iunn10021nuu 211ininuu21nii122211iuiu（1）电压比、电流比（2）不消耗功率（3）电阻变换N+i1+i2u1u2RRi N+i1+i2u1u2RRiRninRininnuiuRi22222111)(121nuu 211iniRiu22 3)等效电路21nuu 211ini+i1+i2u1u2ni1+nu2 2、负电阻变换器N+i1+i2u1u21）定义：A参数：kk002）性质：=11iu22iukk0021kuu 21kii N+i1+i2u1u2RRiRiRikikuiuRi222211Riu2221kuu 21kii 3、回转器N+i1+i2u1u21）定义：A参数：001rr2）性质：=11iu22iu001rr21riu211uri N+i1+i2u1u2RRiRrRirriurriiuRi2222211)(11Riu2221riu211uri 等效电路+i1+i2u1u2+r i221riu211uri +r i1 例：Na+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u1+u2i2i102201011021002两级回转器构成变压器 一般放大器的信号模型N+u1i1+u2i2N+u1i1+u2i2RS+-uSRL 输入电阻 R iN+u1i1+u2i2RLR i+u1Rii1 N+u1i1+u2i2RS+-uSRL+u2-UOC i2RO+-1121ARAuussocRsRRuuiis111121)(uRARARRuissioc记为 Ri1Auuoc +u1i1+u2i2+-RiA u1Ro一般放大器的信号模型当 RS = 0 时，Suu 1111Auuoc记为A u111121)(uRARARRuissioc +uDi1+uoi2+-RiA uDRou+u-uD= u+ - u-uD = u+ - u-uo0+Ucc-UccA= uo / uD DoAuu 当输出端开路时：理想运算放大器 理想条件： Ri = Ro = 0+uDi1+uoi2+-A uDA=A= uo / uD uD = uo / A =0uD= u+ - u- u+ = u-uD = u+ - u-uo0+Ucc-Ucc +-+uDi1+uoi2+-A uD电路符号：*0为有限值+-+uD+uouou+u- +-+uD+uo+uD+uo+-uou+u-+u+uou- 例3.6（P51）：+-RSRfuSuo+RL+-AFRfRS+-uo+-uSRL +-RSRfuSuo+RLi1ifid01dfiiifii 1foSsRuRu00sSfouRRusfsoRRuu