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

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§__01__ Jane Easily 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 .

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§__02__ No Same as triode

__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 .

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§__03__ No Same as working voltage

__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 `

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§__04__ No Identical R3 resistance

__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 `

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§： 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 .

**■ Links to related literature :**

- A chaotic circuit composed of two transistors
- Chaotic circuit
- Build a Chaos Generator in 5 minutes!
- TB Triode kit purchased from
- Test resistance and capacitance A good helper of diodes and triodes Transistor test display module

**● Related chart Links :**

- chart 1.1.1.1 Two transistor chaotic circuit
- chart 1.1.2.1 The test circuit built on the bread board
- chart 1.1.2.2 With resistance R5 Different , The circuit oscillation mode is changing
- chart 2.1.1 Purchased TO-92 Different triodes
- chart 2.1.2 TO-92 Model in triode
- chart 2.2.1.1 R5 A change in the form of oscillation caused by change
- chart 2.2.1.2 Use 2N3904B
- chart 3.1.1 Trajectory in chaotic oscillation state
- chart 4.1.1.1 R3=10k Under the circumstances
- chart 4.2.1.1 R3=5.5k Sinusoidal oscillation produced by
- chart 4.2.1.2 R3=5.6k Chaotic oscillation caused by
- chart 4.2.1.3 R3=35kΩ The corresponding critical chaotic oscillation state