大学电路理论课程教案线性直流电路9

1、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 aaaaaaaa2221

2、1211=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=+21

3、iibbbbrrrr22211211aaaarrrr22211211=+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=+21uubbbbggg

4、g22211211aaaagggg22211211=+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=+21uibbbbhhhh22211211

5、aaaahhhh22211211=+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

6、+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)(

7、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+u2i2

8、rs+-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

9、 +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)(

10、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)(121nu

11、u 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 i221

12、riu211uri +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+ =