aps审核课程一电工电子技术

E串E就是有源二端网络的开路电压0开后两端之间的电压，等效电源的内阻R0等于有源二端网络中所有电源均除去后所得到的）电阻元件：电压电流关系：u=Ri，电压电流同 能量：t0电感元件：电压电流关系：u=Ldi，电流比电压滞后 能量：1 感抗：X= 电容元件：电压电流关系：i=Cdu，电压比电流滞后 能量：1 容抗：X=

阻抗Z R2+

−

)2 R2+(ωL−1

=

12π

12π=（Il 3Ip）功率：P 3UlIlcos电路的暂态分析：换路定则（从t0−到t0+

τ+U(1−e电源电路负载激励响应电流电压电动势电阻电子功率开路短路电压源电流源中性线（零线）相线线电压相电压基波高次谐波（放点过程）零状态响应（充电过程）直流静态分析：耦合电阻为开路I=UCC−UBE≈UCCI= = −I C动态分析：耦合电阻为短路交流负载曲线（斜率更陡，输出电压与输入电压相位相反）产生非线性失真（饱和失真、截止失真：怎样调节？调节RB，使得IB变化，IB变大Q升高）微变等效电路法：等效电路图输入电阻r =300+1+β26=300+26 uA=U0=u

R′RLrbe

一般来说，放大电路的输入阻抗大些较好ri≈rbeRB1//RB2//[rbe+1βRE]

=（U∞−

RC分压式偏置放大电路（图）I≈I≈ V=RB2U≈IR≈I RB1+RB RB1+RB2 E C多级放大电路：耦合方式（Q点独立，分析调试设计方便，但是不适合理想运放：虚短：u+=u− 虚断：i+=i−=0RC、LC振荡电路滤波电路 触发器载流子空穴自由电子P型半导体N型半导体导通截止稳压管发射极基极集电极负反馈正反馈场效应管（输入电阻高、稳定性好）ElectricalElectricalEngineeringintroducesthebasicconceptsandbasiclawsofelectricalcircuits,aswellasthemethodsofDCandACanalysisandsoon.DC-analysisismainlyabouttheapplicationofKirchhoff'slawsandThevenin'sTheorem,whileAC-analysisismoreinclinedtotheeffectofresistance,inductanceandcapacitanceontheelectricalcircuitandthetransientanalysisofthecircuit.Kirchhoff'slawisdividedintotwoparts:Kirchhoff'scurrentlaw(appliedtonodes)atanyinstant,theinflowsofthecurrentatanodeshouldbeequaltotheoutflows.Kirchhoff'svoltagelaw(usedincircuit)inacompletecircuit,thetotaldropofvoltageshouldbeequaltothetotalrise.Theanalysismethodsofthecircuit:theequivalenttransformationbetweenvoltagesourceandcurrentsource,branchescurrentmethod,nodesvoltagemethod,superpositiontheorem,Thevenin'stheoremandNortontheorem.Thevenin'sTheorem:Anytwo-terminallinearactivenetworkscanbereplacedbyanidealvoltagesourceEandaninternalresistanceR_0.Eequalsthevoltageofthetwo-terminalopencircuitU_0.Thatmeansthevoltagewithoutanyload.R_0isequaltotheequivalentresistanceinsidethetwo-terminalnetwork(Similartotheblackbox)Resistanceelements:therelationshipbetweenvoltageandcurrent:uRi,voltageandcurrenthavethesamephase energy:∫_0^t▒〗〖Ri^2dtInductorelements:therelationshipbetweenvoltageandcurrent:uLdidt,currentisearlierthanvoltageby90° energy:1/2Li^2 inductance:X_L=2πfLCapacitiveelements:therelationshipbetweenvoltageandcurrentiCdudt,voltageisearlierthancurrentby90° energy:1/2Cu^2 capacitance:X_C12πfCRLCseriescircuit:takethecurrentdirectionasthebase,anddrawthephasediagramimpedance|Z|=(R^2+〖(X_L-X_C))^2)=(R^2+〖(ωL-1/ωC)^ThefrequencycharacteristicsofRCseriescircuit:lowpass,highpass,bandpassfilter(circuitdiagram,frequencycharacteristicsdiagram)seriesresonancethetotalvoltageandcurrentinthecircuithavethesamephase,X_L〖=X_C,resonantfrequencyf_0=1/(2πLC),thecurrentreachesthemaximum,thevoltageonalargecapacitiveelementisveryhigh.Itisalsoknownasvoltageresonant.Parallelresonance:thetotalvoltageandcurrentinthecircuithavethesamephase,theresonantfrequencyf_01/(2πLC),thetotalcurrentreachesaminimum,whileoneofthebranchhasalargecurrent.Itisalsoknownascurrentresonance.Theconnectionoftheloadinthecircuithastwoways:starconnection(U_l=√3U_p,I_l=I_p)andtriangularconnection(U_l=U_p,(I_l=√3I_p)Power:P=√3U_lI_lcos⁡Non-sinusoidalperiodiccurrentofthecircuitcanbeexpandedbytheFourierThetransientanalysisofthecircuit:changeprinciple(fromt=0_-tot=0_+transiency,thevoltageoftheinductorelementandthecapacitorelementcannotbesuddenlychanged);RCcircuit:timeconstant:τ=RC;fullresponse:u_C=U_0e^(-t/τ)+U(1-e^(-t/Transformerworkingprinciple,workingprincipleofACmotors,theworkingdiagramof电源powercircuitloadexcitationresponse电流current电压voltage电阻Resistanceelectron功率power开路opencircuitshortcircuitvoltagesource电流源currentsource中性线（零线）neutrallinezero(ElectronicElectronicEngineeringintroducesthebasicknowledgeofsemiconductordiodeandtransistor,thebasicamplifiercircuit,integratedoperationalamplifiersandlogicgates.Diode:PNjunctioncanonlyconductbyoneway.Volt-amperecharacteristiccurveofthesemiconductordiodeTransistor:Commonemitterconnection(Whenwewanttomakethetransistorwork,wemustensuretheemitterjunctionforwardbiasedandthecollectorjunctionreversebiased)BasicamplifierThebasicACcommon-emitteramplifier:typeNPN(CircuitStaticanalysis:thecouplingresistanceisopenI_B=(U_CC-U_BE)/R_B≈U_CC/R_BI_C=βI_(B)U_CE=U_CC-I_CR_CDynamicanalysis:thecouplingresistanceisinshort-circuit;theADloadcurve(slopeissteeper,andthephaseoftheoutputvoltageandinputvoltageisonthecontrary)appearsnonlineardistortion(saturationdistortion,cut-offdistortion:howtoregulate?WecanregulateR_B,whichmakesI_Bchange.WhenI_Bislarger,Qincreases)Tinychangeequivalentcircuitmethod:theequivalentcircuitdiagram;inputresistancer_be=300+(1+β)26/I_E=300+26/I_BvoltageamplificationfactorA_u=U̇0/U_i=-β(R_L^')/(r_be+(1+β)R_E)Ingeneral,itisbetterthat,theinputimpedanceoftheamplifierisabitbigger.r_i≈r_beR_B1//R_B2//[r_be+(1+β)R_E],andtheoutputimpedanceoftheamplifierisabitsmaller.r_0=(U_∞/U_0L-1)R_LorR_C.amplifiercircuitwithseparatedvoltage(diagram)I_1≈I_2≈U_CC/(R_B1+R_B2)V_B=R_B2/(R_B1+R_B2)U_CC≈I_ER_E≈I_CR_EEmitterfollower(common-collectoramplifier,diagram)voltageamplificationfactorisapproximatelyequalto1,butalwayslessthan1.ItsinputresistanceislargewhiletheoutputresistanceisMulti-stageamplifiercircuit:coupledmode(resistance-capacitancecoupling–thepointQofalllevelsareindependent.Itiseasytodesign,anglicizeanddebug,butnotsuitablefortheamplificationofslow-changessignal,hardtointegration;directcoupling–suitablefortheamplificationofslow-changessignal,easytointegration;transformercoupling)Differentialamplifier(diagram)cannotamplifythecommon-modesignals,canonlyamplifythedifferent-modesignals.Poweramplifier(diagram)NPNandPNPusetogether,workingattheBstate(notthekey)Feedback:partoralloftheoutputofthesystemwillbeleadedthroughsomecircuittotheinputofthesystem,andhaveaneffectontheinputsignal,thatwillbecalledfeedback.Ifthefeedbacksignalweakenstheoriginalinputsignal,thenthefeedbackiscallednegativefeedback.Ifthefeedbacksignalstrengthenstheoriginalinputsignal,thenthefeedbackiscalledpositivefeedback.IntegratedOperationalAmplifiers:Differentialamplifierisusedastheinputstage,middlestageismadeofoneormorestagesofamplifiers,andtheoutputstageisemitterfolloweroracomplementarysym