# Influence of some factors on testing simple chaotic oscillation circuit

2021-10-14 06:39:23 Jane Medium ： By testing several related factors of chaotic oscillation circuit , Some basic laws are summarized . This provides experimental data for exploring the mechanism of the chaotic oscillation circuit .

` key word ` triode , Chaotic circuit

# §01 Jane Easily chaotic circuit

## One 、 Preliminary test results

In Bowen A chaotic circuit composed of two transistors Describes the use of two BC547B Composed of Chaotic circuit .

### 1、 The circuit principle diagram

This circuit is composed of Kajnjaps stay Build a Chaos Generator in 5 minutes! The article gives . its The schematic diagram is shown in the figure below . `▲ chart 1.1.1.1 Two transistor chaotic circuit `

### 2、 test result

#### （1） Build the experimental circuit

The test circuit built on the bread board is shown in the figure below . among R5 A potentiometer is used for adjustment . `▲ chart 1.1.2.1 The test circuit built on the bread board `

#### （2） Test the waveform

Use an oscilloscope to measure X-Y Display mode to display Q1 Collector and C1 Voltage waveform on . With R5 Different resistance values , You can see that in a certain resistance range （40k ~ 60k Ω） The circuit will produce chaotic oscillation . `▲ chart 1.1.2.2 With resistance R5 Different , The circuit oscillation mode is changing `

## Two 、 Existing problems

During the pre-test , The following questions remain ：

• The influence of working voltage on the circuit ;
• The influence of triode on circuit ;
• Coupling parameters in the circuit R5,R3 Influence on circuit, etc .

By means of TB Triode kit purchased from Experimental tests are carried out for the above different problems ; According to the test results, the design of the circuit is analyzed の Explore the operation principle .

# §02 No Same as triode

## One 、 Type and performance of triode

### 1、 Triode purchased

Here's from TB I bought it from TO-92 Encapsulated triode , Suitable for testing on bread board . `▲ chart 2.1.1 Purchased TO-92 Different triodes ` `▲ chart 2.1.2 TO-92 Model in triode `

### 2、 Triode parameters

Use Transistor recommended test module Test the mechanism characteristics of the purchased triode .

model species Pin hFE Vbe Ic remarks
9012 PNP E-B-C 339 3.1mA 673mV
9013 NPN E-B-C 261 1.8mA643mV
9014 NPN E-B-C 366 2.2mA 663mV
9015 PNP E-B-C 335 3.1mA 661mV
8050 NPN E-B-C 224 2.1mA 633mV
8550 PNP E-B-C 341 3.1mA 626mV
2N2222 NPN E-B-C 253 1.7mA 610mV
2N3904H NPN\E-B-C 186 1.7mA 651mV
2N3904B NPN E-B-C 347 2.1mA 664mV
2N3905 PNP E-B-C 169 1.6mA 660mV
2N3906 PNP E-B-C 355 3.2mA 660mV
A1015 PNP E-C-B 366 3.3mA 658mV
C1815 NPN E-C-B 373 2.2mA 647mV
C945 NPN E-C-B 373 2.2mA 651mV
2N5401 PNP E-B-C 180 1.7mA 636mV
2N5551 NPN E-B-C 162 1.2mA 624mV
BC327 PNP C-B-E 299 2.7mA 630mV
BC337 NPN C-B-E 202 1.9mA 611mV
BC517 NPN C-B-E 116k 5.4mA 1.19V
BC547B NPN C-B-E 311 2.0 651mV 547:50V; 546:80V
BC548B NPN C-B-E 380 2.3mA 643mV
BC549B NPN C-B-E 333 2.1mA 655mV Low noise
BC550 NPN C-B-E 353 2.1mA 647mV
BC556B PNP C-B-E 370 3.4mA 665mV
BC557 PNP C-B-E 309 2.8mA 656mV
BC558B PNP C-B-E 319 2.9mA 644mV
9018 NPN E-B-C 114 0.89mA 714mV
A92 PNP E-B-C 159 1.5mA 630mV
A94 PNP E-B-C 116 1.1mA 610mV
A42 NPN E-B-C 145 1.1mA 611mV

## Two 、 Test chaotic circuits

### One 、 Use 2N3904

There are two models on hand 2N3904

• 2N3904H： hFE Only 186
• 2N3904B：hFE Yes 347

Test the performance of these two transistors in chaotic circuits .

#### （1）2N3904H

Chaotic oscillation can occur . `▲ chart 2.2.1.1 R5 A change in the form of oscillation caused by change `

#### （2）2N3904B `▲ chart 2.2.1.2 Use 2N3904B`

### 2、 Use 9013

test result , Chaotic circuit can form chaotic oscillation .

### 3、 Use 9014

test result , Chaotic circuit can form chaotic oscillation .

### 3、 Use 9018

test result , Chaotic circuit can not form chaotic oscillation . This may be due to 9018 Of hFE Caused by too small .

### 3、 Use BC517

BC517 Is a Darlington tube . test result , The circuit always oscillates , But it can't form chaotic oscillation .

# §03 No Same as working voltage

measuring For the case of chaotic oscillation under different working voltages .

## One 、 Low voltage

When the voltage is lower ,R5 The potentiometer changes the range , The smaller the range of chaotic oscillation . When the voltage is less than 3.5V Left and right ,R5 It is difficult to adjust it into chaotic oscillation .

## Two 、 high voltage

stay 5V ~ 25V in , Circuits can be in R5 Enter chaotic oscillation state in a large range . As the voltage increases , Enter the chaotic oscillation state R5 The higher the upper limit . `▲ chart 3.1.1 Trajectory in chaotic oscillation state `

# §04 No Identical R3 resistance

measuring Try different R3 Influence of resistance on chaotic oscillation . In the initial circuit R3 The values for 15kΩ.

## One 、 Reduce R3

### 1、 test R3=10k

take R3 Reduce to 10k ohm ：

• It's easier for a circuit to go into chaos ;
• The signal C1 The voltage on the increases ; `▲ chart 4.1.1.1 R3=10k Under the circumstances `

### 2、 test R3=4.7k

It is difficult for the test circuit to enter the chaotic oscillation state .

## Two 、 Test with resistance box

Use resistance box instead of R3 It can be changed flexibly R3 size , test R3 Influence of size on chaotic circuit .

### 1、R3 The lower limit of

Adjust the resistance box , Around the 5.5k ohm , The circuit will not produce chaotic oscillation . `▲ chart 4.2.1.1 R3=5.5k Sinusoidal oscillation produced by `

In the same R5 Under the circumstances , take R3 Change to 5.6kΩ when , Circuits can produce chaotic oscillations . `▲ chart 4.2.1.2 R3=5.6k Chaotic oscillation caused by `

### 2、R3 Upper limit

When conditions R3 To 35kΩ When , Readjust R5 It is difficult to make the circuit enter the chaotic oscillation state . The following is in the near case , The chaotic oscillation of the circuit .

It can be seen that the oscillation amplitude is very small . `▲ chart 4.2.1.3 R3=35kΩ The corresponding critical chaotic oscillation state `

# §： Test conclusion

through Several related factors of chaotic oscillation circuit are tested , Some basic laws are summarized . This provides experimental data for exploring the mechanism of the chaotic oscillation circuit .

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