232.4.WYE-DELTATRANSFORMATION(2-5).Determine power as the product of measured voltage and measuredcurrent.NI myDAQ video tutorials:. DMMohmmeter:http://decibel.ni.com/content/docs/Doc-12938.DMMvoltmeter:http://decibel.ni.com/content/docs/DoC-12937: DMM ammeter:http://decibel.ni.com/content/docs/Doc-12939
2.4. WYE-DELTA TRANSFORMATION (2-5) 23 • Determine power as the product of measured voltage and measured current. NI myDAQ video tutorials: • DMM ohmmeter: http://decibel.ni.com/content/docs/DOC-12938 • DMM voltmeter: http://decibel.ni.com/content/docs/DOC-12937 • DMM ammeter: http://decibel.ni.com/content/docs/DOC-12939
24CHAPTER2.RESISTIVECIRCUITS
24 CHAPTER 2. RESISTIVE CIRCUITS
Chapter 3Analysis Techniques3.1Node-Voltage Method (3-1)Apply the node-voltage method to determine the node voltages Vi to V forthe circuit of Figure 3.1 on the following page. From these results determinewhich resistor dissipates themost power and which resistor dissipates theleastpower,andreportthesetwovaluesofpower.Usethese componentvalues:: Isrc1 = 3.79 mA and Isrc2 = 1.84 mA.Vsrc=4.00V.R1 = 3.3 k2, R2 = 2.2 k2, R3 =1.0 k2, and R4 = 4.7 k2NI Multisim MeasurementsEnter the circuit of Figure 3.1 on the next page into NI Multisim. Use DCoperatingpointanalysis todetermine the four nodevoltages and the powerdissipated by each resistor. Display the net names and rename them to match the four node voltages Vito Va; use only thenumbersfor thenetnames.Set up a Simulate→Analyses → DC Operating Point analysis to dis-play the four node voltages and the power associated with each re-sistor
Chapter 3 Analysis Techniques 3.1 Node-Voltage Method (3-1) Apply the node-voltage method to determine the node voltages V1 to V4 for the circuit of Figure 3.1 on the following page. From these results determine which resistor dissipates the most power and which resistor dissipates the least power, and report these two values of power. Use these component values: • Isrc1 = 3.79 mA and Isrc2 = 1.84 mA • Vsrc = 4.00 V • R1 = 3.3 kΩ, R2 = 2.2 kΩ, R3 = 1.0 kΩ, and R4 = 4.7 kΩ NI Multisim Measurements Enter the circuit of Figure 3.1 on the next page into NI Multisim. Use DC operating point analysis to determine the four node voltages and the power dissipated by each resistor. • Display the net names and rename them to match the four node voltages V1 to V4; use only the numbers for the net names. • Set up a Simulate → Analyses → DC Operating Point analysis to display the four node voltages and the power associated with each resistor
26CHAPTER3.ANALYSISTECHNIQUESR2MR1V2R4V4VMM<R3Isrc1Isrc2VsrcFigure 3.1: Circuitfor Problem 3.1NI Multisim video tutorials:. Display and change net names:http://youtu.be/0iz-ph9pJjE·Find node voltages with DC Operating Point analysis:http://youtu.be/gXBCqP17AZs·Find resistorpowerwithDCOperatingPointanalysis:http://youtu.be/NxXmvDw9spoNImyDAQMeasurementsBuild the circuit of Figure 3.1. Use the myDAQDMM (digital multimeter)as a voltmeter to measure each of the four node voltages..Implement the voltage source VsRc according to the circuit diagramof Figure B.2on page 164
26 CHAPTER 3. ANALYSIS TECHNIQUES Figure 3.1: Circuit for Problem 3.1 NI Multisim video tutorials: • Display and change net names: http://youtu.be/0iZ-ph9pJjE • Find node voltages with DC Operating Point analysis: http://youtu.be/gXBCqP17AZs • Find resistor power with DC Operating Point analysis: http://youtu.be/NxXmVDW9spo NI myDAQ Measurements Build the circuit of Figure 3.1. Use the myDAQ DMM (digital multimeter) as a voltmeter to measure each of the four node voltages. • Implement the voltage source VSRC according to the circuit diagram of Figure B.2 on page 164
3.1. NODE-VOLTAGE METHOD (3-1)27. Measure VsRc with the myDAQ DMM voltmeter and adjust the po-tentiometer to set the voltage as close to 4.00 volts as possible. Recordthe actual voltage you measured.. Implement the current source Isrc1 according to the circuit diagramof Figure B.5 on page 167. Use a 330 2 resistor for the adjustmentresistor R.. Measure Isrc1 with the myDAQ DMM ammeter and confirm that thecurrent is close to 3.79 mA. Record the actual current you measured..Implement the current source Isrc2 according to the circuit diagramof Figure B.4 on page 166. Use a 680 2 resistor for the adjustmentresistor R..Measure Isrc2with themyDAQDMM ammeter and confirm that thecurrentiscloseto1.84mA.Record theactual currentyoumeasuredNI myDAQ video tutorials:. DMM voltmeter:http://decibel.ni.com/content/docs/Doc-12937:Measure node voltage:http://decibel.ni.com/content/docs/Doc-12947.DMMammeterhttp://decibel.ni.com/content/docs/Doc-1293gFurtherExplorationwithNImyDAQAs you are by now aware, the analytical solution and the simulation resultsalways agree very well, largely because you can enter exact componentvalues intothe simulator.However,thephysical circuit componentvaluesdo not match the nominal values exactly: the 5%-tolerance resistors canvary ±5% from the nominal value represented by the color-coded bands,and the "1250/R mA" formula for the LM317-based current source is anapproximation.Explore what happens when you recalculate the analytical solution us-ing measured component values
3.1. NODE-VOLTAGE METHOD (3-1) 27 • Measure VSRC with the myDAQ DMM voltmeter and adjust the potentiometer to set the voltage as close to 4.00 volts as possible. Record the actual voltage you measured. • Implement the current source Isrc1 according to the circuit diagram of Figure B.5 on page 167. Use a 330 Ω resistor for the adjustment resistor R. • Measure Isrc1 with the myDAQ DMM ammeter and confirm that the current is close to 3.79 mA. Record the actual current you measured. • Implement the current source Isrc2 according to the circuit diagram of Figure B.4 on page 166. Use a 680 Ω resistor for the adjustment resistor R. • Measure Isrc2 with the myDAQ DMM ammeter and confirm that the current is close to 1.84 mA. Record the actual current you measured. NI myDAQ video tutorials: • DMM voltmeter: http://decibel.ni.com/content/docs/DOC-12937 • Measure node voltage: http://decibel.ni.com/content/docs/DOC-12947 • DMM ammeter: http://decibel.ni.com/content/docs/DOC-12939 Further Exploration with NI myDAQ As you are by now aware, the analytical solution and the simulation results always agree very well, largely because you can enter exact component values into the simulator. However, the physical circuit component values do not match the nominal values exactly: the 5%-tolerance resistors can vary ±5% from the nominal value represented by the color-coded bands, and the “1250/R mA” formula for the LM317-based current source is an approximation. Explore what happens when you recalculate the analytical solution using measured component values