Module 1 1 Circuit Fundamentals Prof Rikky Muller Slides by R Muller Department of EECS University of California Berkeley Announcements No Lab this week Discussion sessions start this week HW1 posted today due next Tuesday Reading Review 16 A B Circuit Concepts HW is intended to be a review of EECS 16B Problems are taken directly from the class You should use techniques learned in EECS 16B University of California Berkeley 2 Power in Watts is the amount of energy transferred Energy in Joules is the capacity to do work and is the time Power and Energy per unit of time E integral of power University of California Berkeley 3 Supplying Power Ideal output impedance Current source Measure with a short circuit How do you model an off current source Ideal output impedance Voltage source Measure with an open circuit How do you model an off voltage source University of California Berkeley 4 Dependent Sources Voltage Controlled Voltage Source VCVS Voltage Controlled Current Source VCCS You can also have current controlled voltage and current sources University of California Berkeley 5 Kirchoff s Voltage Law For a closed loop series path the algebraic sum of all the voltages around any closed loop in a circuit is equal to zero University of California Berkeley 6 Voltage Divider University of California Berkeley 7 Kirchoff s Current Law For a parallel path the total current entering a circuits junction is exactly equal to the total current leaving the same junction University of California Berkeley 8 Current Divider University of California Berkeley 9 Caps Store Energy in Electric Fields A capacitor forms a uniform electric field in V m between its plates maintaining a voltage across them d From Gauss Law I This is all you need to derive Q CV Since E field is proportional to voltage capacitors resist changes in voltage University of California Berkeley 10 What is Magnetic Flux Magnetic Flux is a measure of the total magnetic field that passes through a surface For an inductor it is the magnetic field B passing through the cross sectional area A From Faraday s Law Since B field is proportional to current inductors resist changes in current University of California Berkeley 11 Linear Circuit Elements Element Stores for 0 initial conditions time 0 time Time Dependence none v t i t R i t C dv t dt Initially resists voltage change v t L di t dt Initially resists current change none Charge Q CV dQ I dt Flux LI d V dt short circuit open circuit open circuit short circuit 12 University of California Berkeley Linear Circuit Elements Capacitor i t C dv t dt 1 C t t 0 di t dt 1 L t t t 0 1 L t 0 Capacitors have memory They initially oppose changes in voltage Their voltage depends on initial condition and history of current v t v t 0 i t dt V 0 i t dt 1 C t t 0 i t i t 0 v t dt I 0 v t dt Inductors have memory They initially oppose changes in current Their current depends on initial condition and history of voltage 13 Inductors v t L The Principle of Superposition A circuit with multiple voltage and current sources is equal to the sum of simplified circuits using just one source University of California Berkeley 14 Thevenin and Norton Equivalents Vth is computed as open circuit voltage at port nodes Ith is computed as short circuit current across port nodes Zth computed as Vth Ith All independent voltage and current sources are set to zero University of California Berkeley 15 Thevenin and Norton Example 1 Compute Thevenin and Norton models University of California Berkeley 16 Thevenin and Norton Example 1 University of California Berkeley 17 Ideal Op Amp Review Ideal Operational Amplifier Op Amp basics Vout Zin Zout Bandwidth University of California Berkeley 18 KVL applies to Ideal Op Amps in Feedback University of California Berkeley 19 Summary Today we reviewed fundamental circuits concepts Sources KVL KCL Circuit sources and linear circuit elements Voltage and current dividers Superposition Thevenin and Norton equivalent circuits Next lecture circuits as LTI systems University of California Berkeley
View Full Document
Unlocking...