Experiment collection of University "Fundamentals of circuit analysis". Experiment 4 - Research on linear circuit characteristics

experiment Four    Study on the characteristics of linear circuit

Catalog

1  The experiment purpose

2 Experimental instruments and equipment

3 Experimental principle

4  Preview the experiment

5 Experiment content and steps

6 Experimental requirements and precautions

7  Experimental report and thinking questions

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1  The experiment purpose

1. Deepen the understanding of the main characteristics of linear circuits （ Homogeneity 、 Superposition 、 Replaceability ） The understanding of the .

2. Research methods for learning the main characteristics of linear circuits .

2 Experimental instruments and equipment

A multimeter                                               a

Integrated circuit test box                                       a

3 Experimental principle

1. Homogeneity ： In a linear circuit with an independent source , Every response （ Voltage or current ） It is linearly related to the value of the independent source

system , That is, when an independent source increases or decreases k Times , The voltage or current generated by it on each element also increases or decreases k times . be called

Homogeneity of linear circuits （ Or proportionality ）.

2. Superposition ： In a linear circuit composed of multiple independent sources , Every response （ Voltage or current ） It can be seen as by each individual

The algebraic sum of the response produced by the source acting alone , This feature is called superposition （ Or superposition theorem ）.

3. Replaceability ： In linear or nonlinear circuits with unique solutions , If the voltage of a branch is known to be u, The current is i, Then this one

The road can be used “us=u” Voltage source replacement , Or use “is=i” Current source instead of . Replace the voltage in other parts of the rear circuit 、 The current is guaranteed

Keep the original value .

A branch of the theorem can be passive , It can also be called independent source , Or a two terminal circuit （ Also known as generalized Branch ）. but

yes , There should be no coupling between the replaced branch and other parts of the original circuit .

4  Preview the experiment

1. Preview relevant theoretical knowledge , Read the experimental principle carefully .

2. According to the plan 1-1 Circuit shown , Calculate the theoretical value to be measured , Fill in the table respectively 1-1、 surface 1-2.

5 Experiment content and steps

1. Research on superposition theorem of linear circuit

According to the figure 1-1 Shown in “ Linear circuit research module ” The experimental circuit is built on the experimental board .

（1）US1 The power output terminal of is connected to 2P20（US2 When acting alone ,2P20 And GND Connected to a ）,2P22 And 2P05 Connected to a , electric

Resistance 2R4 And 2R5 Connected in series into a 300Ω The resistance of ,2P08 And 2P05 Connected to a ,US2 The power output terminal of the is connected with 2P06 Connected to a （US1 single

When acting alone ,2P06 And GND Connected to a ）,2P09 Receive GND.

（2） After setting up the experimental circuit , Measure when the power supply US1 、US2 Separate action （ Connect only one power supply ） When acting simultaneously with ,

Voltage in each branch （ Or current ）, Fill in the table 1-1 in , And calculate the power consumed on the resistance of each branch and the power provided by the power supply

, Study the following problems respectively ：

chart 1-1   Experimental circuit of superposition theorem research

1） Voltage in any branch of the circuit （ Or current ） Whether it conforms to the superposition theorem with the power supply ？

2）US1、US2 When acting at the same time, the power consumed on any resistive element is equal to US1、US2 When acting alone, it consumes

Whether the sum of the power of conforms to the superposition theorem ？

3） Power Supply US1、US2 At the same time, the total power consumed by the circuit and US1、US2 Whether the sum of power provided when acting alone conforms to

Superposition theorem ？

2. Research on the homogeneity of linear circuits

According to the figure 1-1 Experimental circuit , send US1=0V（ take US1 Remove the power , Connect with a short wire R1、R2 Both ends ）. By table 1-2 Measurements

According to the , Fill in the table .

surface 1-2   Research on circuit homogeneity

voltage Power Supply	UR1（V）		UR2（V）		UR3（V）		IR2（mA）
	Theoretical value	Measured value	Theoretical value	Measured value	Theoretical value	Measured value	Theoretical value	Measured value
US2=5V
US2=10V
US2=15V

6 Experimental requirements and precautions

1. Pay attention to the correct use of multimeter .

2. Power supply voltage values in all measuring circuits , The value measured by the multimeter shall prevail .

7  Experimental report and thinking questions

1. List the measurement data sheets .

2. Analyze the measurement results , Deepen the understanding of three important theorems .