Nodal Analysis in Electric Circuits I Lab - Lab 6 Overview

Lab 6: Nodal Analysis Electric Circuits I Lab EECE 2105 Electric Circuits I Laboratory LAB 6: Nodal Analysis Student Name: Cessar Lechuga Gerardo Gamez Moreno 1

Lab 6: Nodal Analysis Electric Circuits I Lab LAB 6: Nodal Analysis A. OBJECTIVES  Demonstrate the validity of the node voltage method through experimental measurements  Gain further familiarization with PSpice simulations of electric circuits  Practice the resistance color code  Practice current and voltage measurements B. EQUIPMENT  HP-3631A DC Power supply  Digital Multimeter (DMM)  Prototype Board  Device Test Leads and Cables  Desktop Computer C. PARTS  1/2 Watt Resistors: 910 Ω, 1.2 kΩ, 2x 2.2 kΩ, 2x 3.6 kΩ  Hook-up Wires (#20 or #22 gauge solid conductor) D. BEFORE THE LAB 1) Methods of Analysis The nodal analysis techniques are used to solve complex networks with a single source or networks with more than one source that are not in series or parallel. The mesh analysis will determine the currents of the network, while the nodal analysis approach will provide the potential levels of the nodes of the network with respect to some reference. The application of each technique follows a sequence of steps, each of which will result in a set of equations with the desired unknowns. It is then only a matter of solving these equations for the variables, whether they are currents or voltages. 2) Common Ground It should be clear at this point that all electric circuits contain a reference point which we usually refer to as the ground. In the first part of this laboratory experiment, we will be handling two DC power supplies at the same time (see Figure 1). Both of their negative terminals are connected to 2

Lab 6: Nodal Analysis Electric Circuits I Lab a reference ground. Therefore, in your device you are required to create a ground that is common to both of these supplies (hence, common ground ). The easiest way to achieve this is to connect a banana plug cable between the negative common terminals of the two supplies to be used. E. IN THE LAB 1) Nodal Analysis on Circuit with Two DC Supplies (a) Measure each one of the resistors’ resistances used in the circuit of Figure 1. R 1 = 1.17kohms R 2 = 3.506 kohms R 3 =0.902kohms R 4 = 2.165 kohms Color code R 1 = _brown, red, red,gold color code R 2 = _orange, blue, red,gold Color code R 3 = _white, Brown, brown, gold color code R 4 = red, red, red, gold (b) Build the circuit shown in Figure 1. Notice that the circuit now utilizes two DC power supplies. Your DC Supply device has three of these; choose wisely, making sure to connect common grounds together before turning power ON. Figure 1: Electric Circuit with Two DC Supplies (c) Using the measured resistor values, determine nodal voltage V a using nodal analysis. You should show all work and calculations. Be clear and neat! CALCULATIONS: (use pSpice) V a (calculated) = 9.55 V (d) Using the calculated value of V a and the measured resistor values, calculate the currents I R1 and I R3 . 3

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Lab 6: Nodal Analysis Electric Circuits I Lab I R1 (calculated) = __14.45/1.2k = 12.04mA I R3 (calculated) = 9.55/0.91 = 10.49mA (e) Now turn ON the power supply, and measure the nodal voltage V a . V a (measured) = 9.629 V (f) Measure currents I R1 and I R3 , recalling to break the corresponding branch circuit. Also remember: positive probe takes the current, negative probe releases the current. I R1 (measured) = 12.317mA I R3 (measured) = 10.665mA (g) How do calculated and measured results for V a , I R1 , and I R3 compare? Determine the percent differences for each parameter. V a %Difference = 0.82% I R1 %Difference =2.30% I R3 %Difference =1.57% Take a screenshot of your PSpice circuit schematic, showing voltage and current values, make a printout, and attach it to your report. ** Show your results to your instructor to obtain a signature. 4

Lab 6: Nodal Analysis Electric Circuits I Lab 2) Nodal Analysis on a Bridge Network (a) Go to step (b) below. First measure, then Build the circuit shown in Figure 2. Figure 2: Bridge Network (b) Measure each one of the resistors’ resistances used in the circuit. R 1 = 3,53kohms R 2 = 2.16kohms R 3 = 3.5kohms R 4 = 1.17kohms R 5 = 2.17kohms (c) Using the measured resistor values, determine resistor voltage V 5 and the branch current I 5 using nodal analysis . You should show all work and calculations. Be clear and neat. CALCULATIONS: Use pSpice as indicated ahead in 2(g) V 5 (calculated) = 1.626V I 5 (calculated) = 738.92 microA (d) Measure the voltage V 5 while being careful on how you make multimeter probe connections: recall that you attach positive probe on the positive side label, and the negative probe on the negative side label. V 5 (measured) = 1.583V (e) Measure the current I 5 while being careful on how you make proper multimeter connections: recall that after breaking the branch circuit, you should attach the positive probe at the point from which current is flowing, and the negative probe at the point to which the current is being released; see the labeled arrow for current I 5 to know its assumed direction. 5

Lab 6: Nodal Analysis Electric Circuits I Lab I 5 (measured) = 0.7144mA (f) Finally, determine the percent differences between calculated and measured values of V 5 and I 5 . V 5 %Difference =2.64% I 5 %Difference = 3.19% (g) On your station’s desktop computer, open the PSpice software in order to simulate the electric circuit from Figure 2. You will be performing a DC simulation, from which you need to obtain the same electrical parameters that were previously measured: V 5 , and I 5 . Make sure all component values are exactly the same as in the diagram. ** Show your results to your instructor to obtain a signature. Instructor’s Signature: Jaime Ramos **When done with the laboratory, please return every component to its respective storage. Thank you! F. AFTER THE LAB 6

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Lab 6: Nodal Analysis Electric Circuits I Lab 1) What is the procedure of nodal analysis? Explain the steps in the procedure with as many details as possible! 1)Firstly mark all the nodes 2) Then give the number to the node and mention the node voltage also 3)Consider a node as a reference node and the potential at that node is equal to zero 4)Apply KCL at each node and find out the equation in terms of node voltages 5)Now solve out the equation of voltages 2) When is necessary to define a supernode? When there is a voltage source between two nodes than that combination of nodes is called a supernode Don’t forget to attach the PSpice circuit schematic with your name pasted unto it! 7

Lab 6

Related Documents