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+u2i2i1Na+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u1+u2i2i122211211AAAA=11iu22iuaaaaAAAA22211211=11iuaaiu22aaiu11=aaaaAAAA22211211bbiu11=aaaaAAAA22211211=bbbbAAAA22211211bbiu22aaaaAAAA22211211=bbbbAAAA2221121122iuaaaaAAAA22211211=bbbbAAAA2221121122iu11iuaaaaAAAA22211211=bbbbAAAA2221121122211211AAAA2、串联Na+i1a+i2au2au1aNb+i1b+i2bu1bu2bNa+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u2+u1i1i2Na+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u2+u1i1i221ii21uu22211211RRRR==aauu21+bbuu2121uuaaii21aaaaRRRR22211211=+bbii21bbbbRRRR22211211aaaaRRRR22211211=+21iibbbbRRRR22211211aaaaRRRR22211211=+bbbbRRRR2221121122211211RRRR3、并联Na+i1a+i2au2au1aNb+i1b+i2bu1bu2bNa+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u2+u1i1i2••••Na+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u2+u1i1i2••••21uu22211211GGGG=21ii21ii=aaii21+bbii21aauu21aaaaGGGG22211211=+bbuu21bbbbGGGG22211211aaaaGGGG22211211=+21uubbbbGGGG22211211aaaaGGGG22211211=+bbbbGGGG2221121122211211GGGG4、混联Na+i1a+i2au2au1aNb+i1b+i2bu1bu2bNa+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u2+u1i1i2••Na+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u2+u1i1i2•••21ui22211211HHHH=21iu21iu=aaiu21+bbiu21aaui21aaaaHHHH22211211=+bbui21bbbbHHHH22211211aaaaHHHH22211211=+21uibbbbHHHH22211211aaaaHHHH22211211=+bbbbHHHH2221121122211211HHHH•例：+iki312+iki312+iki3122003i2+u1+u22iikiuu21=203k2ii21uu=11111111203k3114k=+分别求R参数，再相加•5、与电源和负载的联接N+u1—i1+u2—i2RS+-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+u1—i1+u2—i2RS+-uSRL1）、输入电阻RiN+u1—i1+u2—i2RLRi2）、输出电阻N+u1—i1+u2—i2RS+-uSRL+u2-UOCi2RO+-N+u1—i1+u2—i2RS+-uSRL3）、电压传输比u2/u14）、电流传输比i2/i12）、输出电阻RON+u1—i1+u2—i2RS+-uSRL3）、电压传输比u2/u14）、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+u1—i1+u2—i2RS+-uSRL求：1）、输入电阻Ri)(2122111iAuAu)(2222211iAuAiLRiu22代入2221121111ARAARAiuRLLi)()(2122111iARiAuL)()(2222211iARiAiLN+u1—i1+u2—i2RS+-uS求：1）、输出电阻Ro)(2122111iAuAu)(2222211iAuAissRiuu11代入1121ARAuussoc+uoc—ocuAu111ocuAi211socsocRuAuuA2111N+u1—i1+u2—i2RS+-uS求：2）、输出电阻Ro)(2122111iAuAu)(2222211iAuAissRiuu11代入1222ARAuisssc+isc—sciAu121sciAi221sscsscRiAuiA2212=011211222ARAARAiuRssscoco1222ARAuisssc1121ARAuussocN+u1—i1+u2—i2RS+-uSRL+u2-uOCi2RO+-N+u1—i1+u2—i2RS+-uS求：3）、电压传输比u2/u1)(2122111iAuAu)(2222211iAuAi代入121112ARARuuLLRLLRuAuAu2122111LRiu22LRui22N+u1—i1+u2—i2RS+-uS求：4）、电流传输比i2/i1)(2122111iAuAu)(2222211iAuAi代入2221121ARAiiLRL)()(2222211iARiAiLLRiu222）、输出电阻RON+u1—i1+u2—i2RS+-uSRL3）、电压传输比u2/u14）、电流传输比i2/i1例：已知：N的H参数，uS,RS,RL求：1）、输入电阻+u2—RS+-uSRL求：1）、输入电阻Ri2121111uHiHu代入LiGHHHHiuR2221121111+u1i1H12u2H11+-H21i1i2H22LGHiHu2212121222112111)(iGHHHiHL+u2—RS+-uS=0求：2）、输出电阻Ro2221212uHiHi代入SoRHHHHiuR11211222221+u1i1H12u2H11+-H21i1i2H22SRHuHi1121212222111221)(uHuRHHHS••+u2—RS+-uSRL求：3）、电压传输比u2/u12121111uHiHu代入11211222112112)(HRHHHHRHuuLL+u1i1H12u2H11+-H21i1i2H22LGHiHu2212122122212211)(uHuHGHHL221221uHGHiL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=11iu22iunn100=11iu22iunn10021nuu211ininuu21nii122211iuiu（1）电压比、电流比（2）不消耗功率（3）电阻变换N+i1+i2u1u2RRiN+i1+i2u1u2RRiRninRininnuiuRi22222111)(121nuu211iniRiu22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：kk002）性质：=11iu22iukk0021kuu21kiiN+i1+i2u1u2RRiRiRikikuiuRi222211Riu2221kuu21kii•3、回转器N+i1+i2u1u21）定义：A参数：001rr2）性质：=11iu22iu001rr21riu211uriN+i1+i2u1u2RRiRrRirriurriiuRi2222211)(11Riu2221riu211uri等效电路+i1+i2u1u2+ri221riu211uri+ri1例：Na+i1a+i2au2au1aNb+i1b+i2bu1bu2b+u1+u2i2i102201011021002两级回转器构成变压器•一般放大器的信号模型N+u1—i1+u2—i2N+u1—i1+u2—i2RS+-uSRL输入电阻RiN+u1—i1+u2—i2RLRi+u1—Rii1N+u1—i1+u2—i2RS+-uSRL+u2-UOCi2RO+-1121ARAuussocRsRRuuiis111121)(uRARARRuissioc记为Ri1Auuoc+u1—i1+u2—i2+-RiAu1Ro一般放大器的信号模型当RS=0时，Suu1111Auuoc记为Au111121)(uRARARRuissioc+uD—i1+uo—i2+-RiAuDRou+u-uD=u+-u-uD=u+-u-uo0+Ucc-UccA=uo/uDDoAuu当输出端开路时：理想运算放大器理想条件：Ri=Ro=0+uD—i1+uo—i2+-AuDA=A=uo/uDuD=uo/A=0uD=u+-u-u+=u-uD=u+-u-uo0+Ucc-Ucc+-+uD—i1+uo—i2+-AuD电路符号：*0为有限值+-+uD—+uo—uou+u-+++-+uD—+uo—+uD+uo+-uou+u-++u+uou-•例3.6（P51）：+-RSRfuSuo+RL+-AFRfRS+-uo+-uS••••RL+-RSRfuSuo+RLi1ifid01dfiiifii1foSsRuRu00sSfouRRusfsoRRuu