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EE188L EE I Laboratory. Lab #4 KVL, KCL and Nodal Analysis. Lab #3 Overview. First Week Simulation using MultiSim (see Multisim.ppt) Wye-Delta calculations Activity #2 – Build circuit Measure voltages, calculate currents Verify KVL (through step 10 of Activity #2) Second Week
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EE188L EE I Laboratory Lab #4KVL, KCL and Nodal Analysis
Lab #3 Overview • First Week • Simulation using MultiSim (see Multisim.ppt) • Wye-Delta calculations • Activity #2 – Build circuit • Measure voltages, calculate currents • Verify KVL (through step 10 of Activity #2) • Second Week • Activity #2 – Build same circuit • Verify KCL • Change source voltage • Activity #3 – Modify circuit using Delta-Wye • Nodal Analysis Calculations
Wye-Delta Transformation Delta or D Wye or Y Y to Δ Equations Δ to Y
Kirchhoff’s Voltage Law, KVL Loop (0, 1, 2, 0) V0,1 + V1,2 + V2,0 = 0 V -3 V + VR1 - VR3 = 0 V Loop (0, 3, 2, 0) V0,3 + V3,2 + V2,0 = 0 V VR4 + VR2 - VR3 = 0 V For example: V1,2 = - V2,1 = VR1
Nodal Analysis 1 A current is entering the node if the current is leaving the device. A current is leaving the node if the current is entering the device.
Nodal Analysis 2 Apply Ohm’s Law (I = V/R) for R1: current entering node 2 = (V1 - V2) / R1 current leaving node 2 = (V2 - V1) / R1
Kirchhoff’s Current Law, KCL Shade indicates a node At node 1, V1=3 v.due to source At node 0, V0=0 v. due to ground KCL at node 3: KCL at node 2:
Nodal Analysis Shade indicates a node Substitute the known voltages into the equations that were obtained at nodes 2 & 3 Solve the two equations for V2 and V3 You can put the two equations in matrix form and solve using Matlab or any mathematics program (or your calculator).