Circuit and circuit modelActual electrical component: a battery or a light bulb.Ideal circuit component:aCurrentmathematical model of an actualelectriccomponent.LampBatteryRsARTVsIdeal circuitActualelectricalEmphasizethemaincharactercomponentcomponentNeglecttheleftcharacter
Circuit and circuit model • Actual electrical component: a battery or a light bulb Actual electrical component Ideal circuit component Emphasize the main character Neglect the left character • Ideal circuit component: a mathematical model of an actual electric component. R1 V s Rs
Circuit model: A commonly used mathematical model forelectric systemR147.0.1C3L18OscillatorR20.445mHYI17C10kUI7MHzBCeTAntennaSBL-1C1Mixer2200pF≥R3EQIL23,42.5,6>10kC42N2222AC222.7mH9102200pF(see text)C5LC7≥R4910532220to>R11U.Pin8W47R10.R610kC82+C11100kL3R5>GAINT0.1C1612-Vdc100mF1mH100k100mFSupply716V16VU2BC151/2TL072U2A0.47C9R9C10512TL07216V1.0mF15k7AudioL.OmF316VOutput16VC146R12R8C170.00221015k100mFR7U316VC18C130.1LM386NiM0.1C120.0033Audiopoweramp
Circuit model: A commonly used mathematical model for electric system
Lumped elements → Lumped circuitActual scale of the circuit is muchi2i1smaller than the wavelengthrelating to the running frequencyVof the circuit.ii=i2Circuit Type:V is certain. Linear----Nonlinear? Time invariant----Time variant.Passive----ActiveLumped----Distributive
Lumped elements Lumped circuit i2 + V - i1 i1=i2 V is certain Actual scale of the circuit is much smaller than the wavelength relating to the running frequency of the circuit. Circuit Type: • Linear-Nonlinear • Time invariant-Time variant • Passive-Active • Lumped-Distributive