Introduction to 1-L
1- 1-2 ohm's law
1-3 Kirchhoff's law
Kirchhoff's law was put forward by the German physicist Kirchhoff. Kirchhoff's law is one of the most basic and important laws in circuit theory. The basic laws of current and voltage in the circuit are summarized. It includes Kirchhoff's current law (KCL) and Kirchhoff's voltage law (KVL). Kirchhoff's law Kirchhoff's law is the basic law of voltage and current in the circuit, and it is the basis of analyzing and calculating more complex circuits. It was put forward by German physicist G.R. Kirchhoff (1824 ~ 1887) in 1845. It can be used to analyze DC circuits, AC circuits and nonlinear circuits with electronic components. When analyzing a circuit with Kirchhoff's law, it is only related to the connection mode of the circuit, and has nothing to do with the properties of the components that make up the circuit. Kirchhoff's law includes current law (KCL) and voltage law (KVL). The former is applied to nodes in the circuit, and the latter is applied to loops in the circuit.
Kirchhoff's law is the basic electrical law for solving complex circuits. From 65438 to 1940s, due to the rapid development of electronic technology, the circuits became more and more complicated. Some circuits are network-like, and there are some intersections (nodes) formed by three or more branches in the network. This complex circuit can not be solved by the formula of series-parallel circuit. Kirchhoff, who just graduated from the University of Koenigsberg, Germany, was only 2 1 year old. In his 1 paper, Kirchhoff proposed two laws suitable for this kind of network circuit calculation, namely the famous Kirchhoff's law. This law can quickly solve any complex circuit, thus successfully solving this difficult problem that hinders the development of electrical technology. Kirchhoff's law is based on the law of charge conservation, ohm's law and voltage loop theorem, and it is strictly established under the condition of stable current. When Kirchhoff's first equation and the second equation are used together, the current values of each branch in the circuit can be calculated correctly and quickly. Because the electromagnetic wave of quasi-steady current (low frequency alternating current) is much larger than the scale of the circuit, its current and voltage at every moment in the circuit can satisfy Kirchhoff's law well enough. Therefore, the application scope of Kirchhoff's law can also be extended to AC circuits.
1-4 combination of resistance and power supply
1-5 Simplifying the Circuit with△-Y Transform
1-6 power supply transformation
1-7 voltage and current distribution
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Chapter II General Analysis of Resistance Circuits
2-l node analysis
The basic guiding ideology of node analysis method is to use unknown node voltage instead of unknown branch voltage to establish circuit equations, thus reducing the number of simultaneous equations. Node voltage refers to the voltage of independent nodes to dependent nodes. The node current equation is established by applying Kirchhoff's current law, and then the branch current is expressed by node voltage. Finally, the method to solve the node voltage is called node analysis method.
1, select the reference node (node ③) and the reference direction of each branch current,
Using Kirchhoff's current law, the current equations of independent nodes (node ① and node ②) are listed respectively.
2. According to Kirchhoff's voltage law and Ohm's law, a table is established from the node voltage and the known branch resistance.
Branch equation representing branch current.
3. Combine the branch equation with the node equation, eliminate the branch current variable in the node equation and replace it with the node voltage variable. After shifting the term, the node equation with two node voltages as variables is obtained.
2-2 grid analysis
According to Kirchhoff's law, the number of circuits that can provide an independent KVL equation is b-n+ 1.
Mesh is just one group.
Grid flow: a closed imaginary flow that flows alone along the boundary of each grid. Generally speaking, for m grids, self-resistance× grid current+Σ (+-) mutual resistance× adjacency.
The grid current+Σ voltage in the grid rises.
1, select the grid current as the variable, and mark the direction of the variable (always clockwise).
2. According to this law, the grid equation is established by observation.
3. Grid current solution
4. Calculate other quantities required to be solved from the grid current.
2-3 money superposition
2-4 Thevenin Theorem and Norton Theorem
Thevenin theorem: A single-port network N, a linear resistor with independent power supply, can be equivalent to a single-port network with a voltage source and a resistor in series in port characteristics. The voltage of the voltage source is equal to the one-port network of the voltage uoc when the load is open; Resistor R0 is the equivalent resistance of one-port network N0 when all independent power sources in one-port network are zero.
Thevenin theorem (also translated as Thevenin theorem), also known as the law of equivalent voltage source, is an electrical theorem put forward by French scientist L·C· Thevenin in 1883. As early as 1853, Helmholtz also put forward this theorem, so it is also called Helmholtz-Davinan theorem. The content is that the two ends of a linear network containing independent voltage source, independent current source and resistor can be electrically equivalent through the series resistor combination of independent voltage source V and relaxed two-terminal network. In a single-frequency AC system, this theorem applies not only to resistance, but also to generalized impedance.
For one-port network (two-terminal network) with independent source, linear resistor and linear controlled source, it can be equivalent to a one-port network (two-terminal network) with voltage source and resistor in series. The voltage of the voltage source is the open circuit voltage of the one-port network (two-terminal network), and the series resistance is the equivalent resistance when all independent sources in the network are set to zero when viewed from both ends of the one-port network (two-terminal network).
Uoc is called the open circuit voltage. Ro is called Thevenin equivalent resistance. In electronic circuits, when one-port network is regarded as power supply, this resistance is often called output resistance, which is often expressed as Ro; When one-port network is regarded as a load, it is called input resistance and is often expressed as Ri. The series one-port network of voltage source uoc and resistor Ro is usually called Thevenin equivalent circuit.
When the port voltage and current of one-port network adopt relevant reference directions, the equation of the port voltage-current relationship can be expressed as: U=R0i+uoc.
Maximum power transmission under 2-5 DC condition
The maximum power transmission (Theorem 1) is the condition for the one-port network with linear impedance to transmit the maximum power to the variable resistance load. When the theorem is satisfied, it is called maximum power matching. At this time, the maximum power obtained by the load resistor (element) RL is PMAX = UOC 2/4R0.
Maximum power transmission is the theorem that the maximum power can be obtained when the load matches the power supply. The theorem is divided into two parts: DC circuit and AC circuit, and the contents are as follows. One-port network working in sinusoidal steady state supplies power to load ZL=RL+jXL. If one-port network can use Thevenin (also called Thevenin) equivalent circuit (where ZO = RO+JXO, RO >；; 0), the maximum average power pmax = UOC 2/4r0 can be obtained when the load impedance is equal to the * * * yoke complex number including the output impedance of the source-port network (that is, the resistance components are equal and the reactance components are only equal in magnitude and opposite in sign). This kind of matching is called * * * yoke matching. In the design of communication and electronic equipment, it is often required to meet the requirements of * * * yoke matching in order to make the load get the maximum power.
Meet the maximum power matching condition (rl = ro >；; 0), the absorption power of Ro is equal to that of RL, and the power transmission efficiency is h=50% for voltage source uoc. For independent sources in a single-port network n, the efficiency may be lower. Power system requires as much efficiency as possible to make full use of energy, and power matching conditions cannot be adopted. However, in measurement, electronics and information engineering, we often focus on getting the maximum power from weak signals, without paying attention to efficiency.
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Chapter III Resistance Circuit with Operational Amplifier
3- 1 operational amplifier
Operational amplifier (referred to as "operational amplifier") is a kind of circuit unit with high magnification. In practical circuits, it usually forms a functional module together with the feedback network. Because of its early application in analog computers to realize mathematical operations, it was named "operational amplifier". Operational amplifier is a circuit unit named from the functional point of view, which can be realized by discrete devices or semiconductor chips. With the development of semiconductor technology, most operational amplifiers exist in monolithic form. There are many kinds of operational amplifiers, which are widely used in electronic industry.
The first purpose of operational amplifier design is to convert analog voltage into digital for addition, subtraction, multiplication and division, and it has also become the basic component of analog computer. The application of ideal operational amplifier in circuit system design far exceeds the calculation of addition, subtraction, multiplication and division. Nowadays, operational amplifiers, whether using transistors or vacuum tubes, discrete components or integrated circuits, have gradually approached the requirements of ideal operational amplifiers. Early operational amplifiers were designed with vacuum tubes, but now they are mostly integrated circuit components. However, if the demand for amplifiers in the system exceeds the demand for integrated circuit amplifiers, discrete components are usually used to realize these special operational amplifiers.
At the end of 1960s, Fairchild Semiconductor introduced the first widely used integrated circuit operational amplifier, model μA709, designed by Bob Widlar. However, 709 was quickly replaced by the new product μA74 1, with better performance, more stability and easier use. 74 1 operational amplifier has become a unique symbol in the development history of microelectronics industry. After decades of evolution, it has not been replaced. Many IC manufacturers are still producing 74 1. Up to now, μA74 1 is still a typical textbook for explaining the principle of operational amplifier in the department of electronic engineering in colleges and universities.
3-2 circuit with operational amplifier resistance
3-3 Voltage Follower (Isolator)
3-4 Analog Addition and Subtraction
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Chapter IV Inductance and Capacitance
4-channel inductance
4-2 capacitor
4 13 combination of inductor and capacitor
4-4 * duality
4-5 Simple Capacitance Operational Amplifier Circuit
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Chapter V First-order Circuits
5-l unit step excitation function
5-2 passive RL circuit
5-3 passive Rc circuit
5-4 active RL circuit
5-5 active RC circuit
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Chapter VI Second-order Circuits
6-L passive RLC parallel circuit
6-2 passive RLC series circuit
Full response of 6-3 RLC circuit
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Chapter VII Sine and Phasor
Characteristic m of 7- 1- sine quantity
The forced response of 7-2 sine excitation function is small.
7-3 Effective values of current and voltage
7-4 compound excitation function
7-5 phasor
7-phasor relations on 6r, L and C elements
7-7 impedance
7-8 admittance
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Chapter 8 Steady-state Analysis of Sine Circuit
8-L Node, Grid and Loop Analysis
8-2 superposition theorem, power transformation and Thevenin theorem
8-3 phasor diagram
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Chapter 9 Power and Power Factor
9- 1 instantaneous power
9-2 Average Power
9-3 Apparent Power and Power Factor
9-4 complex power
Maximum power transmission under 9-5 AC condition
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Chapter 10 frequency response
10-I parallel resonance
10-2 series harmonic purification
10-3 Other resonant circuits
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Chapter 11 Magnetic Coupling Circuit
1 1- 1 mutual inductance
1 1-2 linear transformer
LL-3 ideal transformer
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Chapter 12 Three-phase Circuit
12-L three-phase voltage
12-2 Y-Y- Y three-phase circuit connection
12-3 triangle (triangle) connection
The use of 12-4 power meter
Power measurement of 12-5 three-phase system
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Chapter 13 two-port network
13- 1 admittance parameter
13-2 two-port equivalent network
13-3 impedance parameter
13- 1 mixing parameters
13-5 transmission parameters
13-6 two-port network connection
13-7 * gyrator
13-8 * negative impedance converter (NIC)
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Chapter 14 Fourier waveform analysis method
14-L Fourier trigonometric series
Exponential form of 14-2 Fourier series
The symmetry of the waveform should be rejected.
14-4 line spectrum
14-5 waveform synthesis
14-6 Effective value and average power
Application of 14-7 Fourier series in circuit analysis
Definition of 14-8 Fourier transform
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Chapter 15 Laplace Transform Method
15-l Laplace transform definition
15-2 unit pulse function
15-3 * time domain convolution and time domain response of circuit
Laplace transform of some simple time functions
Several Basic Theorems of Laplace Transform in 15-5
15-6 partial fraction method
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15-8 transfer function (network function) H(s)
15-9 complex frequency plane
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Chapter 16 Network Graph Theory
16- 1 definitions and symbols
16-2 incidence matrix and Kirchhoff's current law
16-3 loop matrix and Kirchhoff's voltage law
The relationship between 16-4 graph matrices
16-5 Tellegen theorem
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Chapter 17 Network Matrix Equation
17- 1 direct analysis method
17-2 node analysis method
17-3 loop analysis method
17-4 controlled power source network analysis
17-5 state variables and standard state equations
Column writing of 17-6 standard state equation
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Chapter 18 Simple Nonlinear Circuits
18- 1 nonlinear element
18-2 simple nonlinear resistance circuit
18-3 small signal analysis method
18-4 decomposes the circuit into linear and nonlinear parts.
Voltammetric characteristic combination of 18-5
Newton-Raphson method
18-7 general nonlinear resistance circuit
Analysis of state vacancies: phase plane
18-9 phase trace characteristics!
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Chapter 19 * Circuit Design
19-I design process
19-2 simple passive and active low-pass filters
19-3 bandpass circuit
Chapter 20 * Switched Capacitor Circuit
20- 1 MOS switch
20-2 Analog Operation
20-3 first-order filter
Chapter 2 1 Distributed Parameter Circuit
2l- 1 Introduction
Ac steady-state operation of 2 1-2 transmission line distributed parameter circuit
2 1-3 lossless distributed parameter circuit
Two special cases of 2 1-4 lossy transmission line
2 1-5 finite length transmission line distributed parameter circuit
2 1-6 finite lossless transmission line
2 1-7 lossless transmission line terminated with arbitrary impedance
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The appendix exercises the answers.
philology
Note: The chapters marked with an asterisk (*) can be selected in teaching.