Department of Electrical and Computer Engineering, University of Dayton, Spring 2017
PRELAB 3 Instructions:
Simulate the circuits below in Multisim, obtain oscilloscope screen captures and multimeter
measurements of all simulation results before the laboratory session. Whenever you are
displaying two related signals on the oscilloscope, you should align the ground markers of
both signals as well as choose a proper Volts/Div setting so as to be able to make a meaningful
comparison of the two oscilloscope signals. Measure peak-to-peak voltages of both the input
and the output and the frequency of the output. Make sure you do everything you are asked
to do in order to get maximum points. Show all the obtained screen captures in your prelab
report.
Prepare a typed up report. Submit a pdf of your report electronically on Isidore. A formal write up is not required. However keep your report annotated, clear and succinct. That means you still need to label figures and tables if included and clearly state questions you are answering
NOTE ABOUT THE VIRTUAL AGILENT OSCILLOSCOPE PROBES IN SIMULATION IN THE FIGURES BELOW.
PLEASE TAKE NOTE OF THE FACT THAT IN FIGURE 1 BELOW, FOR INSTANCE, THE TWO PROBES OF THE
VIRTUAL AGILENT OSCILLOSCOPE IN SIMULATION ARE THE “X” AND “Y” PROBES. THE GROUND
PROBE FOR EACH “X” AND “Y” PROBE LIKE YOU HAVE ON THE REAL AGILENT OSCILLOSCOPE IS NOT
SHOWN IN THE FIGURE (AND IS NOT VISIBLE IN SIMULATION) HOWEVER ALL VOLTAGE WAVEFORM
MEASUREMENTS ON THE VIRTUAL OSCILLOSCOPE ARE WITH RESPECT TO THE INVISIBLE GROUND OF
THE CIRCUIT IN SIMULATION. WITH THIS IN MIND, IT SHOULD BE OBVIOUS THAT FIGURE 1 BELOW
SHOWS “X” PROBE IS MEASURING THE VOLTAGE ON THE OUTPUT OF THE FUNCTION GENERATOR
WITH RESPECT TO GROUND AND “Y” PROBE IS MEASURING THE OUTPUT VOLTAGE AFTER THE DIODE
WITH RESPECT TO GROUND.
You are required to simulate the circuits on Figure 1, Figure 2 and Figure 3 for values of load
resistance R1 = 330Ω, 7.5kΩ, and 120kΩ. Include oscilloscope captures, voltage and current measurements. Below, I show you what you should get for R1 equal to 100Ω and 270Ω, but, again, you are expected to do it for R1 = 330Ω, 7.5kΩ, and 120kΩ, as stated earlier. To get full credit, make sure you align the grounds, use the same vertical sensitivity and show the peak-to-peak voltage measurements for both channels like I am doing in the following illustrations. Before starting:
The circuits below (Figures 1, 2 and 3) are built with transformer TS_PQ4_10. The problem is TS_PQ4_10 exists in Multisim version 11.0 but has been removed from version 12 onward. However, I believe all of you (in class) are running Multisim 12 or up. You will have to replace the TS_PQ4_10 transformer of version 11.0 with the 1P2S transformer of version 12 with few tweaks.
Department of Electrical and Computer Engineering, University of Dayton, Spring 2017
Once you place the transformer 1P2S, double-click it, select the Value tab, and make these changes (see Note right underneath Figure a for further explanation): Np1 = 7.78, Ns1 = 1, Ns2 = 1, Lm = 10.0038 mH, Le = 0.146 mH, Rp = 66 mΩ, Rs1 = 0.25 mΩ, Rs2 = 0.25 mΩ. Figure a shows you how you need to connect the terminals of the 1P2S transformer so as to mimic the TS_PQ4_10 transformer.
Figure a: 1P2S setup
Note:
Np1, Ns1, and Ns2 are respectively the number of turns in Primary coil 1, Secondary coil 1, and Secondary coil 2 in the Turns tab (select each coil and enter the appropriate value).
Lm refers to the Constant Inductance setting in the Core tab (select Non-ideal core and enter the inductance value as 10.0038m).
Le refers to the Symmetric leakage inductance in the Leakage inductance tab (select Symmetric leakage inductance and enter 0.146m).
Rp, Rs1, and Rs2 are respectively the Custom resistances of Primary coil 1, Secondary coil 1, and Secondary coil 2 in the Resistance tab (select Custom resistance and enter the appropriate values).
Remember: For the rest of the Prelab, the modified 1P2S transformer of Figure a should be put in place of the TS_PQ4_10 transformer in Figures 1, 2 and 3 befow if you are using Multsim version 12 and above.
T1
7.78:1:1
Department of Electrical and Computer Engineering, University of Dayton, Spring 2017
Part 1: Full wave rectifier (with load) Connect the resistive load to the full wave rectifier circuit as shown in Figure 1. Using a dual channel
oscilloscope, observe how the output voltage waveform is affected by changes in the load resistance.
Get a screen capture of the voltage across half of the transformer secondary output and the output
voltage of rectifier for R1 = 330Ω, 7.5kΩ, and 120kΩ. It should be obvious by now that in Figure 1 below,
“XMM1” and “XMM2” are an ammeter and voltmeter respectively. In Multisim, be sure to change
“XMM1” setting from the default voltage to the ampere meter setting or your circuit will not produce
the desired results.
Figure 1 : Full wave rectifier with load