Activity 1.1.5b Circuit Theory: Simulation Introduction As much fun as it is to analyze circuits by hand, the process becomes tedious as circuits grow in size and complexity. This is where Circuit Design Software (CDS) comes to the rescue. As the name implies, the CDS is a software tool that can be used to enter and simulate analog and digital circuit designs. As with most computer applications, the CDS handles the mundane and repetitive tasks associated with analyzing circuits, allowing the designer (you) to concentrate on producing quality and creative designs. In this activity you will gain experience using the Circuit Design Software to analyze simple analog circuits. In future activities we will use the CDS to analyze digital circuits as well. The circuits analyzed are some of the same circuits that were analyzed by hand in the previous activity. Thus, the theoretical and simulation results can be compared. Series Circuit Parallel Circuit Equipment ● Calculator ● Circuit Design Software (CDS) © 2014 Project Lead The Way, Inc. Digital Electronics Activity 1.1.5b Circuit Theory: Simulation – Page 1 Procedure 1. Shown below is the schematic for a simple series circuit. Analyze this circuit to determine its total current and the voltage across each of the two resistors. To make these measurements, add an ammeter and two voltmeters. The second schematic shown is the original circuit with the added meters. Calculated Values: V=12V VR1=3.828 VR2=8.178 Rt= 690Ω It=17.4mAmps Using the CDS, enter and simulate this circuit. Measure and record the circuit’s total current and the voltage across each of the resistors. Measured Values: V=12V VR1=3.826 VR2=8.174 Rt= 690Ω It=17mAmps 2. Using the CDS, analyze the circuit shown below to determine IT, VR1, VR2, & VR3. Add the appropriate ammeters and voltmeters. Be sure to put your answer in proper engineering notation and use the correct units. © 2014 Project Lead The Way, Inc. Digital Electronics Activity 1.1.5b Circuit Theory: Simulation – Page 2 It=4.64 VR1=2.181 VR2=5.567 VR3=1.253 This circuit was analyzed by hand in the previous activity. How do these measured values compare to the previously calculated values? If they do not match, review your circuit, your calculations, and make any necessary corrections. The hand calculations and CDS values match up exactly 3. Using the CDS, analyze the circuit shown below to determine IT, VR1, VR2, VR3, & VR4. Do the measured values compare to your previously calculated values in the previous activity? The measured values match with my calculated values with around a 0.5% margin of error It=0.249 VR1=0.67 VR2=2.479 VR3=0.819 VR4=2.033 4. Using the CDS, analyze the circuit shown below to determine IT, IR1, IR2, & IR3. Do the measured values compare to your previously calculated values in the previous activity? The measured and hand-calculated values match with a margin of error of around 1.3% It=5.781 IR1=1.463 IR2=1.765 IR3=2.553 © 2014 Project Lead The Way, Inc. Digital Electronics Activity 1.1.5b Circuit Theory: Simulation – Page 3 5. Using the CDS, analyze the circuit shown below to determine IT, IR1, IR2, IR3, & IR4. Do the measured values compare to your previously calculated values in the previous activity? the calculated and hand calculated values are identical It=5.372 IR1=2.222 IR2=0.6 IR3=1.818 IR4=0.732 © 2014 Project Lead The Way, Inc. Digital Electronics Activity 1.1.5b Circuit Theory: Simulation – Page 4 Conclusion 1. It should be obvious that using a CDS to analyze circuits is far easier than performing the calculations by hand. Yet, being able to perform these calculations by hand is still an important skill for a circuit designer. Why? being able to do hand calculations can let you know if there is an error in your circuit design because the values will differ. 2. Using the results from step (3) of the procedure, verify Kirchhoff’s Voltage Law. 0.67 + 2.479+0.819+2.033=6 3. Using the results from step (5) of the procedure, verify Kirchhoff’s Current Law. 2.222 +0.6 +1.818 +0.732 =5.372 © 2014 Project Lead The Way, Inc. Digital Electronics Activity 1.1.5b Circuit Theory: Simulation – Page 5 © 2014 Project Lead The Way, Inc. Digital Electronics Activity 1.1.5b Circuit Theory: Simulation – Page 6