《电路》课程教学资源（PPT课件）第1章 电路模型与电路定律

HHHHHHHHHHHHHHHHHHHHHHistorical ProfilesAlessandro Antonio Volta(1745-1827), an Italian physicist,invented the electric battery--whichprovided the first continuous flowof electricity-- and the capacitor.Born into a noble familyin Como,Italy. Volta was performing electricalexperiments at age 18.His invention oftheBatteryin1796revolutionized theuse of electricity.The publication of hiswork in 1800 marked the beginning ofelectric circuit theory. Volta receivedmany honors during his lifetime.Theunit of voltage or potential difference,伏特the volt, was named in his honor.口贝X

invented the electric battery—which provided the first continuous flow of electricity — and the capacitor. Born into a noble family in Como, Italy. Volta was performing electrical experiments at age 18. His invention of the Battery in 1796 revolutionized the use of electricity.The publication of his work in 1800 marked the beginning of electric circuit theory. Volta received many honors during his lifetime. The unit of voltage or potential difference, the volt, was named in his honor. Historical Profiles Alessandro Antonio Volta(1745-1827), an Italian physicist, 伏 特

HHHHHHHHHHHHHHHHHHHHHHHHistorical ProfilesAndre-Marie Ampere(1775-1836), a French mathematicianand physicist,laid thefoundation ofelectrodynamics. He defined theelectric current and developed a way tomeasure it in the 1820s.Born Lyons ,France. Ampere at age 12mastered Latin in a few weeks. as he wasintensely interested inmathematics andmany of the best mathematical workswere in Latin.He was a brilliant scientistand a prolific writer. He formulated thelaws of electromagne-tics. He inventedthe electromagnet and the ammeter.The unit of electric current, the ampere,was named after him安培口

Historical Profiles Andre-Marie Ampere(1775-1836), a French mathematician and physicist, laid the foundation of electrodynamics. He defined the electric current and developed a way to measure it in the 1820s. Born Lyons ,France. Ampere at age 12 mastered Latin in a few weeks, as he was intensely interested in mathematics and many of the best mathematical works were in Latin.He was a brilliant scientist and a prolific writer. He formulated the laws of electromagne-tics. He invented the electromagnet and the ammeter. The unit of electric current, the ampere, was named after him. 安 培

HHHHHHHHHHHHHHHHHHHHHHHHistorical ProfilesGeorg Simon Ohm(1787-1854), a German physicist,in 1826experimentallydeterminedthe mostbasiclawrelatingvoltage and currentfor a resistor.Ohm's work wasinitiallydenied by critics.Born of humble beginningsinErlangen, Bavaria, Ohm threw himselfinto electrical research. His effortsresulted in his famous law. He wasawardedtheCopleyMedalin1841bytheRoyalSociety ofLondon.In 1849he was given the Professor ofPhysicschair by the University of Munich. Tohonorhim, the unit of resistance was欧姆named the ohm.回贝X

Historical Profiles Georg Simon Ohm(1787-1854), a German physicist, in 1826 experimentally determined the most basic law relating voltage and current for a resistor. Ohm’s work was initially denied by critics. Born of humble beginnings in Erlangen, Bavaria, Ohm threw himself into electrical research. His efforts resulted in his famous law. He was awarded the Copley Medal in 1841 by the Royal Society of London. In 1849, he was given the Professor of Physics chair by the University of Munich. To honor him, the unit of resistance was named the ohm. 欧 姆

HHHHHHHHHHHHHHHHHHHHHHHHistorical ProfilesGustav Robert Kirchhoff(1824-1887), a German physicist,stated two basic laws in 1847 concerning therelationship between the currents and voltagesin an electrical network. Kirchhoff's laws,along with Ohm's law, form the basis ofcircuit theiry.Born the son of a lawyer in Konigsberg,East Prussia, Kirchhoff entered the Universityof Konigsberg at age 18 and later became alecturer inBerlin. His collaborative workinspectroscopy with German chemist RobertBunsen led to the discovery of cesium in 1860and rubidium in 1861. Kirchhoff was alsocredited with theKirchhoff law ofradiation基尔霍夫Thus Kirchhoff is famous among engineers,chemists, and physicists.日0

Historical Profiles Gustav Robert Kirchhoff(1824-1887), a German physicist, stated two basic laws in 1847 concerning the relationship between the currents and voltages in an electrical network. Kirchhoff’s laws, along with Ohm’s law, form the basis of circuit theiry. Born the son of a lawyer in Konigsberg, East Prussia, Kirchhoff entered the University of Konigsberg at age 18 and later became a lecturer in Berlin. His collaborative work in spectroscopy with German chemist Robert Bunsen led to the discovery of cesium in 1860 and rubidium in 1861. Kirchhoff was also credited with the Kirchhoff law of radiation. Thus Kirchhoff is famous among engineers, chemists, and physicists. 基尔霍夫

HHHHHHHHHHHHHHHHHHHHHHHS 1-1电路和电路模型Circuits &Circuit Modles1.电路2.电路的作用3.电路的组成4.电路模型

1.电路 2.电路的作用 3.电路的组成 4.电路模型 §1-1 电路和电路模型 Circuits  Circuit Modles

HHHHHHHHHHHHHHHHHHHHHH1.电路 Circuits负载开关LoadSwitch电源Sourse灯泡Lamp干电池Battery2.电路的作用3.电路的组成反回贝

1.电路 Circuits 2.电路的作用 3.电路的组成 干电池 Battery 灯泡 Lamp 负载 Load 电源 Sourse 开关 Switch

HHHHHHHHHHHHHHHHHHHHHHH实际的电路由实际电路设备和电路器件组成：可归结为基本电路器件：实际电路器件电阻器、电源、电感线圈实际电路基本器件电容器、半导体管等理二端元件的一个端子的电流一定特点：在任何时刻，等于从剪母出的电巍，电不端子之商荫电怪与单值量。戴“尖微调电容器E日

上述理想元件称为集总参数元件(简称集总元 件)，其构成的电路称集总参数电路(简称集总电 路)。理想电路元件是假想元件，它是一种理想 化的模型，并具有精确的数学定义。 理想电路元件——电阻、电压源、电流源、 电感、 电容、受控源等。 实际的电路 ——由实际电路设备和电路器件组成； 实际电路器件 ——可归结为基本电路器件； 实际电路基本器件 ——电阻器、电源、电感线圈、 电容器、半导体管等。 + - + -   棒装线圈 工字形电感 固定电感器 “尖波杀手”电感 电 池 稳压电源 水泥电阻 金属膜电阻 绕线式电阻 半导体二极管 三极管 特点：在任何时刻，流入二端元件的一个端子的电流一定 等于从另一端流出的电流，两个端子之间的电压为单值量

HHHHHHHHHHHHHHHHHHHHHHH电路模型用理想电路元件代替实际电路器件则构成理想电路模型。在不同条件下，同一实际电路器件可能用不同的电路模型来模拟。负载开关LoadSwitch灯电源Rs:00LampSourseIRUsT电路模型干电池CircuitModelsBattery回0

电路模型 —— 用理想电路元件代替实际电路器 件则构成理想电路模型。在不同条件下，同一实 际电路器件可能用不同的电路模型来模拟。 灯 Lamp 电源 Sourse 负载 开关 Load Switch 干电池 Battery 电路模型 Circuit Models US RS R

HHHHHHHHHHHHHHHHHHHHHHHS 1-2电流和电压的参考方向Reference Directions of Current & Voltage1.电流及其参考方向2.电压及其参考方向日

§1-2 电流和电压的参考方向 Reference Directions of Current  Voltage 1.电流及其参考方向 2.电压及其参考方向

HHHHHHHHHHHHHHHHHH1.电流及其参考方向正电电流实际方向荷电流：dqi=dti的单位:安培(Ampere)流电流参考方向及图示：任意的方向回

1.电流及其参考方向 → → 电流参考方向及图示：任意选定一方向作为电流 的 方向。 电流： i 的单位：安培(Ampere) or 安 (A) 电流实际方向 → → → → → i → → → → → → → → → → → 电子                   正电 荷 dt dq i = iAB A B i 