EEE3307 ELECTRONICS I LABORATORY MANUAL
Contents
1. Transistors and other components can become extremely hot and cause severe burns if touched If resistors or other components on your proto board catch fire turn off the power supply and notify the instructor If electronic instruments catch fire press the Emergency Disconnect red button These small electrical fires extinguish quickly after the power is shut off Avoid using fire extinguishers on electronic instruments Explosion When using electrolytic capacitors be careful to observe proper polarity and do not exceed the voltage rating Electrolytic capacitors can explode and cause injury A first aid kit is located on the wall near the door Proceed to Student Health Services if needed Guidelines for Laboratory Notebook The laboratory notebook is a record of all work pertaining to the experiment This record should be sufficiently complete so that you or anyone else of similar technical background can duplicate the experiment and data by simply following your laboratory notebook Record everything directly into the notebook during the experiment Do not use scratch paper for recording data Do not trust your memory to fill in the details at a later time Organization in your notebook is important Descriptive headings should be used to separate and identify the various parts of the experiment Record data in chronological order A neat organized and complete record of an experiment is just as important as the experimental work 12. Avoid contact with conductors in energized electrical circuits Electrocution has been reported at de voltages as low as 42 volts Just 100 mA of current passing through the chest is usually fatal Muscle contractions can prevent the person from moving away while being electrocuted Do not touch someone who is being shocked while still in contact with the electrical conductor or you may also be electrocuted Instead press the Emergency Disconnect red button located near the door to the laboratory This shuts off all power except the lights Make sure your hands are dry The resistance of dry unbroken skin is relatively high and thus reduces the risk of shock Skin that is broken wet or damp with sweat has a low resistance When working with an energized circuit work with only your right hand keeping your left hand away from all conductive material This reduces the likelihood of an accident that results in current passing through your heart Be cautious of rings watches and necklaces Skin beneath a ring or watch is damp lowering the skin resistance Shoes covering the feet are much safer than sandals If the victim isn t breathing find someone certified in CPR Be quick Some of the staff in the Department Office are certified in CPR If the victim is unconscious or needs an ambulance contact the Department Office for help or call 911 If able the victim should go to the Student Health Services for examination and treatment Fire
3. 2 with Cg removed 4 Replace R with the ones found in the pre lab preparation part 4 and measure the new unclipped output 5 Repeat 4 with Cr removed 6 Change Rc to 3 2 and measure Ico after the change 26 Report In your lab report present experimental data and compare them with your expected results Discuss any discrepancies make comments and write conclusions Your report will include the following information Laboratory partner Date and time data were taken The pre laboratory results The experimental procedures All calculations or simulation results for each step All plots or waveforms for each step Short summary discussing what was observed for each of the steps given in experiment What you learned oo NO U AR DH Fig 1 27 Ic Saturation Ica VcEo Rac Vreo Rac SLOPE 1 Rac Ica Cut off A Voce OO IcaRac VcEa lcaRAc Fig 2 28 Experiment 5 Transistor Small Signal Amplifiers Goals To study small signal transistor amplifiers References Microelectronics Circuit Analysis and Design D A Neamen McGraw Hill 4 Edition 2007 ISBN 978 0 07 252362 1 Eguipment Oscilloscope Tektronix DPO 4034 Digital Oscilloscope Function Generator Tektronix AFG3022 Dual Channel Function Generator Power Supply Agilent E3630A 2 2222 Bipolar Transistors Breadboard Capacitors available in the laboratory Re
4. For the common emitter amplifier using a by capacitor Cr the voltage gain and input resistance R AV wal R R R ER PI Ob nV kT q 817 m For the common emitter amplifier without a by capacitor the voltage gain and input resistance become BxRe R du m R DxR r B 1 xR 152 Mr B x A Emitter Follower Consider the circuit of Figure 2 Repeat 1 through 4 in the Common Emitter Amplifier procedure above for the Emitter Follower The following equations are for the emitter follower B Dx r BUE AA du R Fr HB x RE Rs J R 9 1 IR 30 pi ia eet i Ico Ico For 2N2222 bipolar transistor the Early voltage V4 is above 100 V and current gain is about 150 Computer Simulation Use a circuit simulation program to verify the results found in the preparation Experimental Procedure The purpose of the experiment is to verify the theoretical results Use Cs 10 pF C 710 uF Ce 100 uF and a sinusoidal input at 5 kHz Common Emitter Amplifier 1 Connect the circuit of the Figure 1 with the component values you have calculated in the preparation 2 Measure the small signal voltage gains Av and Av 3 Measure the voltages vs and v and from these measurements calculate the input resistance input resistance v y P R 4 Measure the output voltage with the Ri co
5. Heading The experiment identification number should be at the top of each page Your name and date should be at the top of the first page of each day s experimental work 2 Object A brief but complete statement of what you intend to find out or verify in the experiment should be at the beginning of each experiment 3 Diagram A circuit diagram should be drawn and labeled so that the actual experiment circuitry could be easily duplicated at any time in the future Be especially careful to record all circuit changes made during the experiment 4 Equipment List List those items of equipment which have a direct effect on the accuracy of the data It may be necessary later to locate specific items of equipment for rechecks if discrepancies develop in the results 5 Procedure In general lengthy explanations of procedures are unnecessary Be brief Short commentaries along side the corresponding data may be used Keep in mind the fact that the experiment must be reproducible from the information given in your notebook 6 Data Think carefully about what data is required and prepare suitable data tables Record instrument readings directly Do not use calculated results in place of direct data however calculated results may be recorded in the same table with the direct data Data tables should be clearly identified and each data column labeled and headed by the proper units of measure 7 Calculations Not always necessary but equations and
6. Plot the output waveform versus time Experimental Procedure Connect the circuit in Fig 1 Let the input be a sinusoid of 4 V peak to peak i e 2V to 2 V with 0 V DC offset voltage at 5 kHz Measure the output waveform versus time at your oscilloscope Connnect the circuit in Fig 2 At the input DC votlage Vg of 1 V measure the DC current flowing through the resistance R 1 kQ Change Vs to 2 volts measure the DC current flowing through R again Compare these two results Note that the diode has a turn on voltage of about 0 6 V Report In your lab report present experimental data and compare them with your expected results Discuss any discrepancies make comments and write conclusions Your report will include the following information Laboratory partner Date and time data were taken The pre laboratory results The experimental procedures All calculations or simulation results for each step All plots or waveforms for each step Short summary discussing what was observed for each of the steps given in experiment What you learned oo HO KR VV 13 Vo Fig 1 Vo v P Fig 2 14 Experiment 2 Diode and Applications This experiment should be for two weeks so that the lab will be synchronizied with the lecture Goals To study the characteristics and the applications of PN junction diodes References Microelectronics Circuit Analysis a
7. external capacitors used to provide DC isolation between stages In the upper frequency band the frequency response is limited by internal parasitic capacitances of the transistor For a more detailed analysis refer to the current textbook used Pre laboratory Consider the common emitter amplifier stage you have designed in Experiment 4 Also see Fig 1 in this experiment 1 Low Frequency a Replace Cg with a 0 1 uF capacitor and calculate the lower 3dB frequency C 10 uF and Cr 100 pF 37 b Replace Cr with a 0 1 uF capacitor and calculate the lower 3dB frequency Cg 10 uF and CE 100 pF 2 High Frequency Because the transistor parasitic capacitances are not known and because the upper high frequency might be too high to measure we do the following Connect two capacitors between base emitter and between base collector as shown in Figure 2 Select the values between 100 pF to 400 pF based on availability With these external capacitors connected it may be reasonable to assume that C is approximately equal to the external capacitance and C is approximately the external capacitance plus another 100 pF which is a typical value for the internal parasitic a With the described assumptions and connections calculate the upper 3dB frequency of the amplifier Computer Simulation Use a circuit simulation program to verify the results found in the preparation Experimental Procedure The purpose of the experiment is
8. the input and observe the result Next leave the amplitude the same and add a DC offset in the input There should be an offset control on the generator and again observe the output Make comments b Repeat the same steps for a square wave input Report In your lab report present experimental data and compare them with your expected results Discuss any discrepancies make comments and write conclusions Your report will include the following information 1 Laboratory partner 2 Date and time data were taken 3 The pre laboratory results 4 The experimental procedures 17 5 All calculations or simulation results for each step 6 All plots or waveforms for each step 7 Short summary discussing what was observed for each of the steps given in experiment 8 What you learned Fig 1 Channel A VsQQ Channel B Fig 2 18 Fig 3 Vs Fig 4 Fig 5 19 20 Experiment 3 Transistor Biasing Goals To study the transistor biasing and bias stability References Microelectronics Circuit Analysis and Design D A Neamen McGraw Hill 4 Edition 2007 ISBN 978 0 07 252362 1 Equipment Oscilloscope Tektronix DPO 4034 Digital Oscilloscope Function Generator Tektronix AFG3022 Dual Channel Function Generator Power Supply Agilent E3630A 2N2222 Bipolar Transistors Breadboard Capacitors available in the laboratory Resistors available in the laboratory Background In
9. to verify the theoretical results and notice any discrepancies Low Frequency Connect the CE amplifier in Fig 1 and carry out all the preparation steps For each case measure the lower 3dB frequency and compare it with the theoretical value High Frequency a Connect the two small capacitors as described in the preparation and measure the upper 3dB frequency and compare it with the theoretical value b Remove the two small capacitors and measure the new upper 3dB frequency How different is this compared to a above Report In your lab report present experimental data and compare them with your expected results Discuss any discrepancies make comments and write conclusions Your report will include the following information 1 Laboratory partner 2 Date and time data were taken 38 3 The pre laboratory results 4 The experimental procedures 5 All calculations or simulation results for each step 6 All plots or waveforms for each step 7 Short summary discussing what was observed for each of the steps given in experiment 8 What you learned Vec Vo R Fig 1 E Fig 2 39 40 Experiment 8 Differential Amplifiers Goals To study the characteristics of differential amplifiers References Microelectronics Circuit Analysis and Design D A Neamen McGraw Hill 4 Edition 2007 ISBN 978 0 07 252362 1 Eguipment Oscilloscope Tektronix DPO 4034 Digital Oscilloscope Func
10. was observed for each of the steps given in experiment 8 What you learned Fig la Fig 1b 23 ie A Ve Rc Rg Time Time Fig 2 Fig 3 24 Experiment 4 Transistor AC Amplifiers This experiment would be for two weeks so that the lab can be synchronizied with the lecture Goals To study AC transistor amplifiers References Microelectronics Circuit Analysis and Design D A Neamen McGraw Hill 4 Edition 2007 ISBN 978 0 07 252362 1 Eguipment Oscilloscope Tektronix DPO 4034 Digital Oscilloscope Function Generator Tektronix AFG3022 Dual Channel Function Generator Power Supply Agilent E3630A 2N2222 Bipolar Transistors Breadboard Capacitors available in the laboratory Resistors available in the laboratory Background Information A typical common emitter amplifier stage is shown in the Figure 1 The placement of the O point on the AC load line determines the maximum symmetrical AC component in the collector voltage and current With an arbitrary location of the Q point on the AC load line the maximum unclipped voltage or current will occur first on either the positive or negative cycles of the AC waveform and as the input is increased the output will eventually be clipped on both cycles The maximum unclipped output can be optimized maximized placing the Q point at the center of the AC load line 25 Pre laboratory All the preparation parts must be computed
11. 3 Was there any brief lecture in the lab 4 Did the lab instructor know how to operate the instruments 5 Any comments that may help the lab instructor improve Your name optional Please return to your course instructor 10 Experiment 1 SPICE Circuit Simulation and Equipment Usage Goals To familiarize with Multisim circuit simulation for pre lab prepartion and the use of measurement equipment at the Electronics lab References The following two links are to the Tektronix website for the user manuals for the 4034B Mixed Signal oscilloscope and for the AFG3022 Function generator Oscilloscope http www2 tek com cmswpt madetails lotr ct M A amp cs mur amp ci 16272 amp lc EN Function Generator http www2 tek com cmswpt madetails lotr ct M A amp cs mur amp ci 11920 amp lc EN Please note to download the user manual Tektronix requires that you fill out the user information form before downloading can begin Equipment Oscilloscope Tektronix DPO 4034 Digital Oscilloscope Function Generator Tektronix AFG3022 Dual Channel Function Generator Power Supply Agilent E3630A IN4148 Diode Breadboard Resistors available in the laboratory Tektronix MSO 4034 Oscilloscope Tektronix AFG3022 Function Generator 11 12 Computer Simulation Connect the circuit in Fig 1 using the schematic drawing in your computer simulation software Let the input be a sinusoid of 2 V to 2 V amplitude at 5 kHz R 1 kQ
12. EEE3307 ELECTRONICS I LABORATORY MANUAL DEPARTMENT OF ELECTRICAL amp COMPUTER ENGINEERING University of Central Florida Stands For Opportunity Prepared by Dr Jiann S Yuan Revised Summer 2011 Preface This laboratory book in Electronics I has been revised in order to be up to date with curriculum changes laboratory equipment upgrading and the latest circuit simulation software Every effort has been made to correct all the known errors If you find any additional errors or anything else that you think is an error please contact Dr Yuan at the following email address yuanj mail ucf edu Dr Jiann S Yuan Summer 2011 Table of Contents Saftety Rules and Operations Procedures Laboratory Safety Information Guidelines for Laboratory Notebook Trouble Shooting Hints Experiment 1 SPICE Circuit Simulation and Equipment Usage Experiment 2 Diodes and Applications Experiment 3 Ttransistor Biasing Experiment 4 Transistor AC Amplifiers Experiment 5 Transistor Small Signal Amplfiiers Experiment 6 Design Project Experiment 7 Frequency Response Experiment 8 Differential Amplifiers Experiment Evaluation Form Safety Rules and Operating Procedures 1 Note the location of the Emergency Disconnect red button near the door to shut off power in an emergency Note the location of the nearest telephone map on bulletin board 2 Students are allowed in the laboratory only when the lab instructor is pre
13. before the experiments part Consider the circuit of Fig 1 Let Voc 12 V Ro 6 2 KQ Rg 1 8 and Ry 22 1 Calculate values of so that Ico 5 1 mA and for good bias stability or Rgs 0 1x B 1 xRg 2 Compute the Q point and the maximum unclipped output voltage with Cg included Cg 100 uF 3 Repeat 2 if capacitor Cg is removed 4 With Rc RE and Ri the same as what used in 1 re calculate R and so that the operating point is at the center of the AC load line Re calculate the maximum unclipped output with Cg included CE 100 pF 5 Repeat 4 with the bypass capacitor Cg removed 6 Change the value of Rc to 3 2 kQ and re calculate the DC operating point Ico What do you notice You may find the following equations useful Vss V ge on y _ Veo XR R _ RXR V 077 BB I E RRs oo co BB R B Computer Simulation Use a circuit simulation program to verify the results found in the preparation Experimental Procedure The purpose of the experiment is to verify the theoretical and simulation results Use Cg 1 uF C 1 uF and Cg 100 pF NOTE Make sure capacitors are connected with the correct polarity 1 Build the circuit in Fig 1 with the values you calculated in part 1 of the preparation If necessary re adjust Rj Ro so that Ico 51 mA 2 Measure the maximum sinusoidal unclipped output Set the input frequency to 5 kHz 3 Repeat
14. ed value Measure Ic and Ip and compute the current gain p b If needed adjust VBB so that Ico is about 2 mA Replace the transistor with another one and check if the Ico remains the same Repeat with a third transistor Does the collector current remain the same Why or Why not c Modify the circuit by inserting RE as in the preparationand repeat parts a above d Connect the circuit in Fig 3 using the values you have calculated in the preparation Measure the Q point and compare with expected value e Connect and set the generator to a sinusoidal of 3 kHz Use 10 uF for the capacitor C Make sure the capacitor is connected with the correct polarity Adjust the input amplitude so that none of the waveforms is clipped Observe and include in your report the following waveforms Input voltage vi collector voltage vc emitter voltage vg and collector emitter voltage vcr Plot all those waveforms on a common time scale using 2 to 3 sinusoidal cycles Report In your lab report include theoretical simulated and experimental results and make comment about discrepancies as well as any other observations that you have Your report will also include the following information 1 Laboratory partner 2 Date and time data were taken 3 The pre laboratory results 4 The experimental procedures 22 5 All calculations or simulation results for each step 6 All plots or waveforms for each step 7 Short summary discussing what
15. formation A typical transistor amplifier circuit is shown Fig 1 a Figure 1 b is a simplified equivalent Figure 2 shows a typical DC load line and a Q point The input AC signal disturbs the base current that in turn makes the Q point move on the load line producing a proportionally larger disturbance in the collector current thus producing amplification Fig 3 is the same as Fig 1 with an AC input signal added Pre laboratory Assume Vcc 12 V A Consider the circuit in Fig 1 b with Rc 1 8 KQ Rs 5 6 kQ and Rg 0 Q B Calculate Vgg so that Ic 2 mA Assume p 220 and Vgg 0 7 V Find the Q point C If D changes to 150 what is the new Ic from your circuit simulation Consult with your lab instructor how to change the current gain P in the 2N222 model parameter in MultiSim 21 D Repeat B above if Rg is changed to 1 8 kQ E Consider the circuit in Fig 3 with Rc Rg 1 8 Calculate the values for Rj R2 so that Ico 2 mA Use a sinusoidal input small signal peak to peak voltage of 20 mV and current gain of 150 in your circuit simulation Plot vi vc vg and Vcg versus time Computer Simulation Using a circuit simulation program to simulate the preparation parts Experimental Procedure The purpose of this experiment is to verify the theoretical and simulation results a Connect the circuit of Fig 1 b with values calculated in the pre lab preparation Measure the Q point and compare with expect
16. lding and testing or can test all designs Experiment Build one of the designed amplifiers and measure all the parameters that have been specified Report Compare desired and obtained specifications and make comments Your report will also include the following information 1 Laboratory partner 2 Date and time data were taken 3 The pre laboratory results 4 The experimental procedures 5 All calculations or simulation results for each step 6 All plots or waveforms for each step 7 Short summary discussing what was observed for each of the steps given in experiment 8 What you learned 35 36 Experiment 7 Frequency Response of a Common Emitter Amplifier Stage Goals To study the frequency response of a common emitter amplifier stage and to experimentally verify theoretical results References Microelectronics Circuit Analysis and Design D A Neamen McGraw Hill 4 Edition 2007 ISBN 978 0 07 252362 1 Eguipment Oscilloscope Tektronix DPO 4034 Digital Oscilloscope Function Generator Tektronix AFG3022 Dual Channel Function Generator Power Supply Agilent E3630A 2 2222 Bipolar Transistors Breadboard Capacitors available in the laboratory Resistors available in the laboratory Background Information The frequency response of an amplifier is limited in the low and high frequency bands because of the presence of capacitors In the low frequency band the response is limited because of
17. nction Generator Power Supply Agilent E3630A 2N2222 bipolar tranisstors Breadboard Capacitors available in the laboratory Resistors available in the laboratory Problem Statement Design a small signal voltage amplifier that meets the following specifications 1 Voltage gain of 50 or more 2 Minimum input resistance of 15 3 Output resistance less than 100 Q 4 Maximum unclipped output of 2V peak to peak 5 Power supply voltage of 9 V 6 Lower current drain from supply voltage 34 Hint You may use a multi stage small signal amplifier to achieve desirable input resistance voltage gain output resisntace etc A common emitter amplifier with an emitter resistance but without an emitter by pass capacitor CE is good for high input resistance common emitter amplifier using an emitter by pass capacitor is good for high voltage gain and the use of an emitter follower results in a low output resistance You may use some analytical equations in Experiment 4 and Experiment 5 to help you for calculation and or anlysis Design Deliverables A design document that includes at least the following 1 Complete electrical schematics 2 Design steps with expectations 3 Computer simulation of the design Note 1 Each student must design his or her own amplifier and turn the design document into the lab instructor 2 During the experiment students can choose one of the amplifiers desinged by the members for bui
18. nd Design D A Neamen McGraw Hill 4 Edition 2007 ISBN 978 0 07 252362 1 Eguipment Oscilloscope Tektronix DPO 4034 Digital Oscilloscope Function Generator Tektronix AFG3022 Dual Channel Function Generator Power Supply Agilent E3630A IN4148 Diodes 4 IN5234 Zener Diodes 2 Breadboard Capacitors available in the laboratory Resistors available in the laboratory Background Information Diodes find numerous applications in practices including rectifiers clipping clamping and other signal processing circuits They are also used in temperature compensated biasing and in digital circuits A Rectifiers The basic half wave rectifier is shown in Fig 1 Because filtering is not perfect there will be a residual voltage fluctuation known as ripple on the output voltage The amount of ripple can be reduced by a factor of two by using the full wave rectifier shown in Fig 2 15 B Clipping Circuits Clipping circuits are used I applications where an input voltage should not be allowed to exceed a maximum value and also in wave shaping of signal function generation A typical one is show in Fig 3 The same result can be obtained with the circuit of Fig 4 using two back to back Zener diodes C Clamping Circuit The clamping circuit is a DC level restorer and changes the DC level of an arbitrary waveform to a predetermined one A simple clamping circuit is shown in Fig 5 Pre laboratory Read this laborator
19. nnected and disconnected respectively Use the measurement results to compute the output resistance output resistance Ry x vo vr vr where Vo is the maximum output voltage without Ri connected and vy is the maximum output voltage with Ri connected Emitter Follower Connect the circuit of Figure 2 with component values as calculated in the preparation and repeat all the experimental parts from 1 through 4 in the common emitter amplifier above Report In your lab report present experimental data and compare them with your expected results Discuss any discrepancies make comments and write conclusions Your report will include the following information 1 Laboratory partner 2 Date and time data were taken 3 The pre laboratory results 4 The experimental procedures 31 5 All calculations or simulation results for each step 6 All plots or waveforms for each step 7 Short summary discussing what was observed for each of the steps given in experiment 8 What you learned Vo R Fig 1 Fig 2 32 33 Experiment 6 Design Project This experiment should be for two weeks Goals To design a transistor amplifier that meets given specs Reference Microelectronics Circuit Analysis and Design D A Neamen McGraw Hill 4 Edition 2007 ISBN 978 0 07 252362 1 Eguipment Oscilloscope Tektronix DPO 4034 Digital Oscilloscope Function Generator Tektronix AFG3022 Dual Channel Fu
20. s of preparation part A by experiments to study the diode characteristics and the operation of the various application circuits experimentally For each part test what happens if the input is changed to a triangular or square input Important Because the ground lead of the oscilloscope is internally connected to the ground of the function generator in Fig 2 you cannot connect the ground lead of the oscilloscope to the point of the output voltage Instead you should use two scope channels and use the scope in the differential mode Consult with your lab instructor on how to do that Clipping Circuits a Connect the circuit in Fig 3 Let the input be a sinusoid of frequency 1 kHz Display the input and output waveforms on the oscilloscope Vary the amplitude of the input and observe the result Display the Vout vs Vin transfer characteristics of the circuit on the oscilloscope Change the input waveform to a triangular or square waveform and see what happens b Repeat the same steps for the circuit in Fig 4 Note that the Zener breakdown voltage of 1N5234 is about 6 2 V and Zener diode s forward turn on voltage is about 0 65 V Your input voltage may change to 20 V peak to peak to provide sufficiently larger amplitude Clamping Circuit a Connect the circuit in Fig 5 Let the input be a sinusoid of any amplitude at 1 kHz While observing the output waveform set the oscilloscope scope to be DC coupled vary the amplitude of
21. sample calculations are often given to illustrate the treatment of the experimental data in obtaining the results 8 Graphs Graphs are used to present large amounts of data in a concise visual form Data to be presented in graphical form should be plotted in the laboratory so that any questionable data points can be checked while the experiment is still set up The grid lines in the notebook can be used for most graphs If special graph paper is required affix the graph permanently into the notebook Give all graphs a short descriptive title Label and scale the axes Use units of measure Label each curve if more than one on a graph 9 Results The results should be presented in a form which makes the interpretation easy Large amounts of numerical results are generally presented in graphical form Tables are generally used for small amounts of results Theoretical and experimental results should be on the same graph or arrange in the same table in a way for easy correlation of these results 10 Conclusion This is your interpretation of the results of the experiment as an engineer Be brief and specific Give reasons for important discrepancies Trouble Shooting Hints 1 Be sure that the power is turned on 2 Be sure the ground connections are common 3 Be sure the circuit you built is identical to that in the diagram Do a node by node check 4 Be sure that the supply voltages are correct 5 Be sure you plug in cable to the right
22. sent 3 Open drinks and food are not allowed near the lab benches 4 Report any broken equipment or defective parts to the lab instructor Do not open remove the cover or attempt to repair any equipment 5 When the lab exercise is over all instruments except computers must be turned off Return substitution boxes to the designated location Your lab grade will be affected if your laboratory station is not tidy when you leave 6 University property must not be taken from the laboratory 7 Do not move instruments from one lab station to another lab station 8 Do not tamper with or remove security straps locks or other security devices Do not disable or attempt to defeat the security camera 9 Anyone violating any rules or regulations may be denies access to these facilities I have read and understand these rules and procedures I agree to abide by these rules and procedures at all times while using these facilities I understand that failure to follow these rules and procedures will result in my immediate dismissal from the laboratory and additional disciplinary action may be taken Signature Date Lab Laboratory Safety Information The danger of injury or death from electrical shock fire or explosion is present while conducting experiments in this laboratory To work safely it is important that you understand the prudent practices necessary to minimize the risks and what to do if there is an accident Electrical Shock
23. sistors available in the laboratory Background Information One of the earliest and important applications of bipolar transistors is in small signal amplifiers These are systems that accept input signal of small amplitudes on the order of 100 mV and deliver larger replicas In this experiment we will study the common emitter CE and common collector CC configurations and a variation of the two The common collector amplifier is also known as the emitter follower Common Emitter Amplifier A typical common emitter amplifier stage is shown in the Figure 1 Emitter Follower or Common Collector Amplifier A typical emitter follower is shown in Fig 2 The voltage gain of the emitter follower is close to one but never equal to one The input resistance is significantly higher than that of CE Amplifier and the output resistance is significantly lower 29 Pre laboratory Consider the circuit of Figure 1 with Vcc 12 V Rc 6 2 kQ Re 1 8 Ry 2 2 Rs 1 8 KQ and Cg 100 uF Common Emitter Amplifier 1 Calculate the values Ry Ro so that Ico 1 mA and good bias stability see also preparation in Experiment 3 2 Compute the Q point and the maximum unclipped output voltage 3 Compute the small signal voltage gain Av v viand Av Vo Vs 4 Compute the input and output resistances 5 Repeat 2 to 4 above if capacitor Cg is removed You may find the following equations for the CE amplifier useful
24. terminal in the multimeter to measure the voltage resistance upper terminal or the current lower terminal 6 Be sure that the equipment is set up correctly and you are measuring the correct parameter 7 Be sure the BJT s collector and emitter terminals are in correct orientation 8 If steps 1 through 5 are correct then you probably have used a component with the wrong value or one that doesn t work It is also possible that the equipment does not work although this is not probable or the protoboard you are using may have some unwanted paths between nodes To find your problem you must trace through the voltages in your circuit node by node and compare the signal you have to the signal you expect to have Then if they are different use your engineering judgment to decide what is causing the different or ask your lab assistant Eeperiment Evaluation Form COURSE EEE3307 SEMESTER COURSE INSTRUCTOR LAB INSTRUCTOR EXPERIMENT Please write comments on the following issues PART A experiment 1 Was the experiment successful 2 Did the experimental results match the theory 3 Was the material covered in the lecture 4 Was the experiment instructive 5 Was the lab manual clearly written PART B facility 1 Did all the instruments work properly 2 Were all the needed parts available 3 Any other problems PART C Lab Instructor 1 Was the lab instructor helpful 2 Did the lab instructor know the experiment
25. tion Generator Tektronix AFG3022 Dual Channel Function Generator Power Supply Agilent E3630A 2N2222 Bipolar Transistors Breadboard Capacitors available in the laboratory Resistors available in the laboratory Background Information Differential amplifiers have two inputs and amplify the difference of two inputs The most common differential amplifier is the differential pair shown in Figure 1 When the two transistors are identical matched this amplifier exhibits excellent thermal stability and is the basic building block of the Operational Amplifier An improvement of this circuit is to replace RE by a constant current source This modification is shown in Figure 2 The lower bipolar transistor acts as a constant current source In theory this circuit has a much better common mode rejection ratio CMRR than the circuit of Figure 1 Pre laboratory 1 Assume equal inputs to the differential pair transistors and compute the DC current of each transistor in Figure 1 2 With component values as shown compute the differential mode voltage gain Ava common mode voltage gain Av and common gain rejection ratio CMRR 20 log Avy Av in Figure 1 3 Compute the quiescent current Ico of each transistor in Figure 2 41 4 With component values as shown compute the differential mode gain common mode gain and common mode rejection ratio in Figure 2 Experimental Procedure The purpose of the experiment is to experimentall
26. y experiment carefully to become familiar with the background procedural steps in this experiment Using the circuit simulation software to simulate the following circuits If you do not have access to Multisim LTSpice IV is a free to use spice program available from Linear Technology Inc and can be downloaded from the following site http www linear com designtools software LTspice A For the circuits of Fig 1 and Fig 2 choose available values of Ri and C so that RLC 0 2 second approximately Draw the output waveforms when the input is sinusoidal of frequency 100 Hz and 10 V peak to peak under the following cases 1 Capacitor only is removed Plot the transfer Vout versus Vin characteristics 2 Resistor only is removed 3 Capacitor and resistor are both in place Calculate the peak to peak ripple voltage B Determine the transfer characteristics of the circuits in Fig 3 and Fig 4 Draw the output waveforms assuming that the input is a sinusoid with sufficiently larger amplitude larger than both reference voltages or the Zener voltages amplitude C For the circuit shown in Fig 5 draw the output waveform if the input is a sinusoid Do not neglect the diode turn on voltage 5 0 65 V Select available values of R and C so that RC time constant is equal to 0 2 seconds approximately e g for a capacitor of 10 uF the resistor value should be 20 16 Experimental Procedure Rectifiers Perform all the step
27. y study the characteristics of the differential amplifier 1 Connect the circuit of Figure 1 With the inputs connected together drive the input 10 mV p p at 5 kHz from the function generator and measure the common mode voltage gain 2 Set one of the inputs to AC zero and measure the differential mode voltage gain 3 Compute the common mode rejection ratio CMRR 3 Repeat steps 1 2 and 3 for the circuit in Fig 2 Measure the quiescent current Icg of each transistor Report In your lab report present experimental data and compare them with your expected results Discuss any discrepancies make comments and write conclusions Your report will include the following information Laboratory partner Date and time data were taken The pre laboratory results The experimental procedures All calculations or simulation results for each step All plots or waveforms for each step Short summary discussing what was observed for each of the steps given in experiment What you learned 00 Hp OU 5 0 42 Rec 6 2 k Rn 1 8k Cin 101 Cn 10p Rn 1 8k
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