week5 lab et212

Week 5 Lab - Transistor Biasing

Electronics I and Lab

Transistor Biasing

Introduction:

Week 5 lab is based on the fundamentals of a transistor biasing and the analysis of the circuit.

The goal of Transistor Biasing is to establish a known Q-point in order for the transistor to work efficiently and produce an undistorted output signal. In bipolar transistor circuits, the Q-point is represented by ( VCE, IC ) for the NPN transistors or ( VEC, IC ) for PNP transistors.

Please review the following videos before getting started with this lab:

1. Watch the video: “Video 3: Fundamentals of breadboard”

2. Watch the video: “Video 4: Basic electrical components”

3. Watch the video: “Video 5: Simple resistive circuit with NI myDAQ”

4. Watch the video: Design of a voltage-divider biased common-emitter amplifier using MultiSim and myDAQ

5. View the image: Amp DC Components

Materials and Equipment:

Materials:

· Hardware Parts (In the Toolbox):

. An NPN transistor: 2N3904

. Four resistors: 1 kΩ, 470Ω, 3 kΩ and 6 kΩ

. Jumper wires

Equipment:

· Hardware Equipment:

. Breadboard

. NI myDAQ Instrument device

. Screw Driver

. Screw Terminal connector

. USB Cable

. Multimeter with probes

. Multimeter from NI ELVISmx Instrument Launcher

Procedure:

*** This lab has to be implemented only in hardware (using NI myDAQ) ***

1. Analyze the circuit in the Figure 1 below to calculate the following values: VB, VE, IE, VC and VCE.

2. Construct the circuit shown in Figure 1 below on the breadboard using the transistor and two resistors (RCand RE).

Figure 1

3. Using the jumper wires, screw driver and screw terminal connector, connect the board to NI MyDAQ Instrument Device.

4. Use channel +15V pin out on the NI myDAQ Instrument Device to provide the supply voltage (VCC). Measure the required voltages: VB, VE and VC and currents: IC and IE using the Multimeter.

5. Tabulate the data from step 1 and step 5.

	Calculated	Measured
VB
VE
VC
IE
IC

6. Short the resistor R2 and calculate the values in steps 1.

7. Modify the circuit in Figure 1 to short the resistor R2 and measure the values in step 4.

	Measured values with R2 shorted
VB
VE
VC
IE
IC

Review questions:

1. Compare a calculated and measured values in the table. Discuss whether the values are the same of different. If they are different, provide the reasoning. And how to reduce this difference between calculated and measured values.

2. What happens when R2 is shorted? Why does the measured values change?

3. If the NPN transistor is replaced with a PNP transistor, how does the change in the transistor effect the current and voltage in the circuit?

Deliverables:

1. Analysis of the circuit and calculations of voltages: VBB, VE and VC and currents: IC and IE.

2. Take screenshots of the measurements obtained from function generator and Multimeter on the NI ELVISmx Instrument Launcher on your screen.

Lab Report:

· Use the Lab report template found in the “Tools and Template” link in the navigation center.

· Include all the deliverables.

· Include all the screenshots of the measurements from circuit design on the breadboard using NI myDAQ Instrument Device and measurements from MI ELVISmx Instrument Launcher.

· Save the document as Lab5YourGID.docx (ex: Lab5G00000000.docx) and submit in Blackboard.

Rules for lab submissions:

1. The lab document must be a Word document.  PDF files are NOT accepted.

2. All screenshots must be included.

3. All Multisim screenshots must include the date/time stamp.

4. Any and all Multisim files must be submitted. 

5. Any equations used must be typed in Word.  Copy and paste of equations from outside sources is prohibited.

6. No graphics are allowed in the Word document other than screenshots of circuits from Multisim and hardware if applicable, with the date/time stamp.

7. The lab template should be used.  Specifically, it is brought to your attention that a summary MUST be provided explaining the results of the labs, the relationship of the results to expected results, and any challenges encountered.

8. Hardware portion of labs should include screenshots of the assembled circuit with your name and student GID number written on paper next to the circuit. There should be screenshots of the instrument readings with the date and time stamp on lower right corner clearly shown. See example below.

Any violation of the submission rules above will result in a grade of 1.