模电仿真实验报告
4、若在pspice中进行傅立叶分析，则可在文本输出窗口中找到下面的数据：
HARMONIC FREQUENCY FOURIER NORMALIZED PHASE NORMALIZED
NO (HZ) COMPONENT COMPONENT (DEG) PHASE (DEG)
1 5.000E+02 1.287E+01 1.000E+00 -5.337E+01 0.000E+00 2 1.000E+03 2.629E-01 2.042E-02 -2.688E+01 7.987E+01 3 1.500E+03 7.316E-01 5.683E-02 1.765E+02 3.367E+02 4 2.000E+03 2.082E-02 1.617E-03 6.535E+01 2.788E+02 5 2.500E+03 3.890E-01 3.022E-02 -6.389E+01 2.030E+02 6 3.000E+03 5.401E-02 4.195E-03 -5.747E+01 2.628E+02 7 3.500E+03 1.588E-01 1.234E-02 2.912E+01 4.027E+02 8 4.000E+03 4.816E-02 3.741E-03 9.581E+00 4.366E+02 9 4.500E+03 3.633E-02 2.822E-03 -1.108E+02 3.696E+02
为便于观察，将横坐标范围缩小：
4.0V(500.002,3.8169)3.0V2.0V1.0V0V0HzV(O)0.1KHz0.2KHz0.3KHz0.4KHz0.5KHz Frequency0.6KHz0.7KHz0.8KHz0.9KHz1.0KHz
由于要求Vo≥8V，故改进如下：
将R2取值设为全局变量，从15k到20k进行扫描，间隔1k，得到各波形如下：
R2=15k，Vomax=3.8664V.
4.0V(24.848m,3.8664)2.0V0V-2.0V-4.0V0sV(O) Time2ms4ms6ms8ms10ms12ms14ms16ms18ms20ms22ms24ms26ms28ms30ms
25
模电仿真实验报告
R2=16k,Vomax=5.1017V.
6.0V4.0V(26.928m,5.1017)(24.848m,3.8664)2.0V0V-2.0V-4.0V-6.0V0sV(O) Time2ms4ms6ms8ms10ms12ms14ms16ms18ms20ms22ms24ms26ms28ms30ms
R2=17k,Vomax=7.1819V.
8.0V(28.988m,4.0V(26.928m,5.1017)(24.848m,3.8664)0V-4.0V-8.0V0sV(O) Time2ms4ms6ms8ms10ms12ms14ms16ms18ms20ms22ms24ms26ms28ms30ms
R2=18k,Vomax=11.424V.
12V(29.018m,8V(28.988m,4V(26.928m,5.1017)(24.848m,3.8664)0V-4V-8V-12V0sV(O) Time2ms4ms6ms8ms10ms12ms14ms16ms18ms20ms22ms24ms26ms28ms30ms
R2=19k,Vomax=11.816V,波形失真。
12V(11.022m,11.816)8V(28.988m,4V(26.928m,5.1017)(24.848m,3.8664)(29.018m,0V-4V-8V-12V0sV(O) Time2ms4ms6ms8ms10ms12ms14ms16ms18ms20ms22ms24ms26ms28ms30ms26
模电仿真实验报告
R2=20k,Vomax=11.816V,波形失真。
12V(11.022m,11.816)(13.240m,11.816)8V(28.988m,4V(26.928m,5.1017)(24.848m,3.8664)(29.018m,0V-4V-8V-12V0sV(O) Time2ms4ms6ms8ms10ms12ms14ms16ms18ms20ms22ms24ms26ms28ms30ms
故应取R2=18k。
同理，若从1k扫描到14k，会发现一开始没有振荡，直到R2=10k时，出现阻尼振荡波形如下：
4.0mV2.0mV0V-2.0mV-4.0mV0sV(O) Time2ms4ms6ms8ms10ms12ms14ms16ms18ms20ms22ms24ms26ms28ms30ms
而R2=11k时开始有不稳定振荡输出波形：
400mV200mV0V-200mV-400mV0sV(O) Time2ms4ms6ms8ms10ms12ms14ms16ms18ms20ms22ms24ms26ms28ms30ms
R2=12k时趋于稳定：
2.0V1.0V0V-1.0V-2.0V0sV(O) Time2ms4ms6ms8ms10ms12ms14ms16ms18ms20ms22ms24ms26ms28ms30ms
27
模电仿真实验报告
R2=13k时稳定，Vomax=2.4425V：
3.0V(28.738m,22.0V1.0V-0.0V-1.0V-2.0V-3.0V0sV(O) Time2ms4ms6ms8ms10ms12ms14ms16ms18ms20ms22ms24ms26ms28ms30ms5、当实验中二极管D1或者D2开路，如下图所示 （1）D1开路
D1R91MEGD1N5395R221kD2D1N5395
V1R310k12VdcU1R1210k3-04V-OS1uA741165VOUT0+V+7OS2V2R46.8k12Vdc0C10.047uR56.8kC20.047u0
对该电路进行仿真分析，得到的波形图如下：
12V8V4V0V-4V-8V-12V0sV(R3:2) Time2ms4ms6ms8ms10ms12ms14ms16ms18ms20ms22ms24ms26ms28ms30ms
28