ENGR1500 – Introduction to Engineering Design

ENGR1500 – Introduction to Engineering Design

Skills Lab 2 – Circuit Simulations

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Name:___________________________

Date:____________________________

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Objectives:

• To build and analyze basic circuits in Multisim circuit simulation software.

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Equipment:

Multisim software (National Instruments).

Overview:

• Build and simulate circuits using Multisim software.
• Record results from simulation and from calculations using MS Word into this document (fill in the blanks, indicate yes/no to questions).
• Make screen shot (Print-Screen) of each simulating circuit to make image of the circuit with V and I values visible. Paste images into the MS Word file at appropriate place.
• Make a pdf file of the filled in MS Word document.

Procedure:

1. Open the Multisim software. In Multisim, build circuit 1 as diagrammed.  The primary components of the circuit are the power supply (V_s) and one resistor (R₁).  An icon button to add these basic components is near top left of window.  The square boxes in the circuit are Indicators to act as a DMM to measure current (Ammeter) or to measure voltage (Voltmeter).  An icon button to add Indicators is further to the right from the previous icon button to add basic components.  To connect each node with a wire, place the mouse cursor over a node, and press mouse button to start drawing a wire.  Label each component and indicator as shown in Circuit 1 by right-clicking on the object and selecting Properties.  Feel free to use different values for V_s or R₁ than those suggested.  Add a ground to the circuit, selecting a top left icon button to add the ground.  Add Text to add a “Circuit 1” label near the top and add all the names of the team members.  Save circuit in your P/ drive or on a thumb drive (so that each team member can have a copy of this file for future reference).

CIRCUIT 1

2. To run this simulation of this circuit and to have the indicators display the resulting values of I and V, hit the green arrow near the top middle. The simulation will continually run (producing the same result again and again since this is a DC circuit and nothing changes) until the stop button (red square) is pushed.  Save the Multisim file after running simulation.  Print the circuit.

From this Multisim simulation, write down the values displayed on the indicators.

I_s =_____________________

I₁ = _____________________ does I₁=I_s (yes/no)?

V₁ = ____________________ does V₁ = V_s (yes/no)?

Make the following Calculations and comparisons (show your work).

I₁ = (V₁/R₁) = _______________________ same value as Multisim (yes/no)?

3. With the circuit being simulated with the V and I values displayed, make a screen shot (hit “PrtSc” button, and paste here into this MS Word file.)

4. In Multisim, build circuit 2 as diagrammed. Run the simulation (Green Arrow).  Save the Multisim file after running simulation.

CIRCUIT 2

From this Multisim simulation, write down the values displayed on the indicators.

I_s =_____________________

I₁₂₃ = ____________________

I₄ = _____________________

V₁ = ____________________

V₂ = ____________________

V₃ = ____________________

V₄ = ____________________

Make the following Calculations and comparisons (show your work)

• Theory — Kirchhoff’s Voltage Law (KVL) states that for any continuous loop in a circuit, the sum of the changes in voltage over each component must be equal to zero. In other words, the sum of the voltage rises equals the sum of the voltage drops.

ΣV_rises = ΣV_drops

Provide the equations to illustrate KVL around both loops in in this circuit here.

• Theory — Kirchhoff’s Current Law (KCL): for any node in a circuit, the sum of the currents into the node (current out of node have negative value) must be zero. In other words, the sum of the current IN equals the sum of the OUT of a node.

ΣI_in = ΣI_out                     

Provide the equations to illustrate KCL at the node at the top of the circuit here

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5. With the circuit being simulated with the V and I values displayed, make a screen shot (hit “PrtSc” button, and paste here into this MS Word file.

6. Use Multisim to construct circuit 3. Run the simulation (Green Arrow).  Connect a voltmeter to measure V_out with the polarity provided.  Use this circuit to answer the following questions.

Note: you do not need to have

Where:       R1=380 Ohm

R2=380 Ohm

R3=425 Ohm

R4=425 Ohm

CIRCUIT 3

1. Simulate the circuit and provide the measurement for V_out:

V_out=___________________

Given the above resistor values, rationalize this measurement in a brief response here:

1. Modify R₄ to various values between 415 and 435 Ohms.

Explain what happens to V_out and provide the rationalization for this here:

Due Next Lab: A printout of the above worksheet and the one-page report on the lab.