What is the content of Kirchhoff's law and how to understand it

What is the content of Kirchhoff's law and how to understand it

Kirchhoff's law
Kirchhoff’s law
This paper presents a rule to reveal the inherent relationship between the current flowing into the node and the voltage in the circuit with lumped parameters. It was proposed by German G.R. Kirchhoff in 1845. Kirchhoff's law includes Kirchhoff's first law and Kirchhoff's second law. Kirchhoff's first law is also called Kirchhoff's current law, It means that the algebraic sum of any instantaneous current flowing into any node of the circuit is equal to zero
i1(t)-i2(t)-i6(t)＝0
i2(t)-i3(t)-i4(t)＝0
Kirchhoff's second law is also known as Kirchhoff's voltage law. It means that the algebraic sum of the voltages of each branch is equal to zero at any instant along any circuit. For example, along the ABCA circuit (via branch 2, 3, 6) or abcda circuit (via branch 2, 3, 5, 1) in the graph, the following two expressions hold respectively:
u2(t)+u3(t)-u6(t)＝0
u2(t)+u3(t)+u5(t)-u1(t)＝0
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Kirchhoff's law
Kirchhoff laws
This paper expounds the law of constraint relationship between the current flowing into and out of the node and the voltage along the loop in lumped parameter circuit. It was put forward by German physicist G.R. Kirchhoff in 1845. In the law, the constraint relationship between the current flowing into and out of the node is called Kirchhoff's first law or Kirchhoff's current law, and the constraint relationship between the voltage of each segment in the loop is called Kirchhoff's first law or Kirchhoff's current law Kirchhoff's second law or Kirchhoff's law of voltage
Kirchhoff's current law (KCl) holds that for any node in a lumped parameter circuit, at any instant, the algebraic sum of all currents flowing out of the node is always zero, that is to say
i=0
For the reference direction, the current flowing out of the node is positive and the current flowing into the node is negative
According to this law, for node a in Fig. 1, there is a subordinate
－i1－i2＋i3＋i4=0
Theoretically, Kirchhoff's law of current is the embodiment of the law of charge conservation in the circuit
Kirchhoff's law of voltage (KVL) holds that for any loop in any lumped parameter circuit, at any instant, the algebraic sum of the voltages along each segment of the loop is always zero, i.e
V=0
When the reference direction of the voltage is the same as the detour direction of the circuit, the voltage takes a positive sign in the formula, otherwise it takes a negative sign
According to this law, for the circuit shown in Fig. 2, there is a following
V1+V2-V3-V4=0
Physically, Kirchhoff's law of voltage is the embodiment of the law of conservation of energy in the circuit
The application of Kirchhoff's law is applicable to any lumped parameter circuit, no matter whether the circuit is linear or nonlinear, time-varying or time invariant, steady or transient, because it is only related to the connection mode of the circuit (i.e. the topological structure of the circuit) and has nothing to do with the performance of the components contained in the circuit. The phasor form of the law is KCl: 夒 = 0
KVL: Section = 0 operator, in the form of
KCL：I(S)=0
KVL：V(S)=0
The former is used for sinusoidal steady-state analysis and the latter for complex frequency analysis
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Kirchhoff's law
Kirchhoff laws
This paper expounds the law of constraint relationship between the current flowing into and out of the node and the voltage along the circuit in lumped parameter circuit. It was proposed by German physicist G.R. Kirchhoff in 1845. Lumped parameter circuit refers to the circuit whose maximum linear dimension is far less than the wavelength of current or voltage in the circuit, Kirchhoff's law includes current law and voltage law
Kirchhoff current law (KCl) in any lumped parameter circuit, the algebraic sum of all the current flowing out of the node at any moment is always zero, that is, in terms of the reference direction, the current flowing out of the node takes a positive sign in the formula and the current flowing into the node takes a negative sign. Kirchhoff current law is the embodiment of the law of conservation of charge in the circuit
Kirchhoff's law of voltage (KVL) in any circuit with lumped parameters, at any instant, the algebraic sum of the voltages along each section of the circuit is always zero, that is, when the reference direction of the voltage is the same as the detour direction of the circuit, the voltage takes a positive sign in the formula, otherwise it takes a negative sign. Kirchhoff's law of voltage is the embodiment of the law of conservation of energy in the circuit

What does Kirchhoff's Law mean?

Kirchhoff law includes Kirchhoff voltage law KVL and Kirchhoff current law kcl.kcl The law means that at any instant, the sum of the current flowing to a node is equal to the sum of the current flowing from the node; the law of KVL means that at any instant, the sum of the electromotive force in any circuit is equal to the sum of the voltage drop on each resistance

Kirchhoff current law (KCl)
How it works

At any time, the sum of the current flowing into the node is equal to the sum of the current flowing out of the node. This is the node current law. Generally, the law is the result that is in line with the objective reality obtained by the predecessors through practice and a lot of research. In addition to using it immediately, we should certainly confirm that it is true (there is no doubt about this)