Lab Reports for electrical engineers, Assignments of Electrical Circuit Analysis

Download Lab Reports for electrical engineers and more Assignments Electrical Circuit Analysis in PDF only on Docsity! 1 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Laboratory Manual EE-153L – Introduction to Electrical Engineering Instructor Dr. Muhammad Riaz DEPARTMENT OF ELECTRICAL ENGINEERING Pakistan Institute of Engineering & Applied Sciences Islamabad, Pakistan 2 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual LABORATORY REGULATION AND SAFETY RULES The following regulation and Safety rules must be observed in Laboratory. 1. Safety is everyone's responsibility. Everyone must cooperate to create the safest possible working conditions. Where your personal life and good health are concerned, safety becomes your responsibility. Safety rules are common sense ideas that help prevent injury. When you work with electricity, treat it with respect. If electricity is properly used, it will work for you. Abuse it and you may have trouble. Be sure that all the equipment is properly working before using them for laboratory exercise. Any defective equipment must be reported immediately to the Lab Instructor. 2. Instruction during Lab experiment: Make sure that last connection to be made is your circuit is the power supply and first thing to be disconnected is also power supply. Before giving power supply, always check for short circuit conditions. Equipment should not be removed, transferred to any location without permission from the laboratory staff. Hold test probes by their insulated areas. Some components, such as Resistors, Heat Sinks can get very hot. Always give them time to cool before touching them. 3. Responsibility: it is responsibility of each student working on allocated work station: Switch off the equipment, place the tools & components on their proper place before leaving the laboratory. 4. Lab Report: Report of each lab experiment required to be verified before next experiment, late report submission will NOT be evaluated in the end. Follow the lab report format as recommended by Lab Instructor. 5. Make Up Lab: There will be No Make up lab for individual or a group of students in case of Leave or absent from regular lab session. 5 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Experiment 1 Introduction to Electrical Laboratory, DC Sources and Metering 1.1 Objective The objective of this exercise is to become familiar with the operation and usage of basic DC electrical laboratory devices, namely DC power supplies and digital multimeters. 1.2 Equipment  Digital Multimeter model:_________________________ SRN:__________________  Analog / Digital Trainer Model; ___________________ SRN: ___________________  Adjustable DC Power Supply model:________________ SRN:__________________ 1.3 Bread Board The breadboard consists of two terminal strips and two bus strips (often broken in the center). The connections are spaced 0.1 inch apart which is the standard spacing for many semiconductor chips. These are clustered in groups of five common terminals to allow multiple connections. The exception is the common strip which may have dozens of connection points. These are called buses and are designed for power and ground connections. Interconnections are normally made using small diameter solid hookup wire, usually AWG 22 or 24. Larger gauges may damage the board while smaller gauges do not always make good connections and are easy to break. Figure 1.1: Bread Board 6 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual 1.4 Analog / Digital Trainer  Multi-rail DC power supply  A four range digital volt meter.  Function generator along with a large area of breadboard.  Logic switches and LED indicators.  Bread Board Figure 1.2: Analog / Digital Lab Trainer 7 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual 1.3 Digital Multimeter Multi Meter is an instrument used to measure current, voltage, resistance etc. Below table indicate the rotary switch positions Figure 1.3: Digital Multi Meter 10 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Procedure  Set the adjustable power supply to 2.2 volts. Use both the Coarse and Fine controls to get as close to 2.2 volts as possible.  Record the displayed voltage in the first column of Table below. Using the DMM set to the DC voltage function, set the range to 20 volts full scale. Measure the voltage at the ouput jacks of the power supply.  Be sure to connect the DMM and power supply red lead to red lead, and black lead to black lead. Record the voltage registered by the DMM in the middle column of. Reset the DMM to the 200 volt scale, re-measure the voltage, and record in the final column  Draw diagram of the Bread board here 11 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Experiment 2 To Study the Resistor Color Code 2.1 Objective The objective of this exercise is to become familiar with the calculating resistance through color code and measurement of resistance values using a digital multimeter (DMM). 2.2 Theory Overview The resistor is perhaps the most fundamental of all electrical devices. Its fundamental attribute is the restriction of electrical current flow: The greater the resistance, the greater the restriction of current. Resistance is measured in Ohms. The measurement of resistance in unpowered circuits may be performed with a digital multimeter. Like all components, resistors cannot be manufactured to perfection. That is, there will always be some variance of the true value of the component when compared to its nameplate or nominal value. For precision resistors, typically 1% tolerance or better, the nominal value is usually printed directly on the component. Normally, general purpose components, i.e. those worse than 1%, usually use a color code to indicate their value. The resistor color code typically uses 4 color bands. The first two bands indicate the precision values (i.e. the mantissa) while the third band indicates the power of ten applied (i.e. the number of zeroes to add). The fourth band indicates the tolerance. It is possible to find resistors with five or six bands but they will not be examined in this exercise. Examples are shown below:It is important to note that the physical size of the resistor indicates its power dissipation rating, not its ohmic value. Each color in the code represents a numeral. 0 Black 1 Brown 2 Red 3 Orange 4 Yellow 5 Green 6 Blue 7 Violet 8 Gray 9 White For the fourth, or tolerance, band: 5% Gold 10% Silver 20% None 12 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Fig 2.1 Resistors color code chart For example, a 470 k 5% resistor would have the color code yellow-violet-yellow-gold. Measurement of resistors with a DMM is a very straight forward process. Simply set the DMM to the resistance function and choose the first scale that is higher than the expected value. Clip the leads to the resistor and record the resulting value. 2.3 Equipment 1. Digital Multimeter 2. Resistance (10 Nos) 15 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual 2.5 Questions 1. What is the largest deviation in Table 3.3? Would it ever be possible to find a value that is outside the stated tolerance? Why or why not? 2. If Steps 3 and 4 were to be repeated with another batch of resistors, would the final two columns be identical to the original Table 3.3? Why or why not? 3. Do the measured values of Table 3.3 represent the exact values of the resistors tested? Why or why not? 2.6 Conclusion 16 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Experiment 3 Verification of Ohm’s Law 3.1 Objective This exercise examines Ohm’s law, one of the fundamental laws governing electrical circuits. It states that voltage is equal to the product of current times resistance. 3.2 Theory Overview Ohm’s law Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points. 3.3 Equipment DMM Digital Trainer Resistors 03 Nos: 470 Ω resistor, 1 kΩ resistor. 3.3 kΩ resistor 3.4 Procedure 1. Using color code find the value of each resistor and then measure using DMM and record in table below. Color Codes Tolerance Value (Using Color Codes) Measured Values (Using DMM) 17 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual 2. Build the circuit of Figure 3.1 using the 470 Ω resistor. Set the DMM to measure DC current and insert it in-line between the source and resistor. Set the source for zero volts. Measure and record the current in Table 3.1. Note that the theoretical current is 0 and any measured value other than 0 would produce an undefined percent deviation. Figure 3.1 3. Setting E at 2 volts, determine the theoretical current based on Ohm’s law and record this in Table 3.1. Measure the actual current, determine the deviation, and record these in Table 3.1. Note that Deviation = 100 * (measured – theory) / theory. 4. Repeat step 3 for the remaining source voltages and record values in table 3.1. Table 3.1 (470 Ω) E (volts) I theoretical (mA) I measured (mA) Deviation (mA) 0 2 4 6 8 10 12 20 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Experiment 4 Verification of KVL and Series Resistive Circuit 4.1 Objective The focus of this exercise is an examination of basic series DC circuits with resistors. A key element is Kirchhoff’s Voltage Law which states that the sum of voltage rises around a loop must equal the sum of the voltage drops. The voltage divider rule will also be investigated. 4.2 Theory Overview A series circuit is defined by a single loop in which all components are arranged in daisy-chain fashion. The current is the same at all points in the loop and may be found by dividing the total voltage source by the total resistance. The voltage drops across any resistor may then be found by multiplying that current by the resistor value. Consequently, the voltage drops in a series circuit are directly proportional to the resistance. 4.3 Equipment  DMM  Digital Trainer  Resistors 03 Nos: 1 kΩ, 2.2 kΩ. 3.3 kΩ 4.4 Procedure 1. Circuit Resistance: a. Find value of each resistor using color code and then using DMM, name lowest value as R1 and onward. R1 (Color Code)=__________________ R1 (DMM):___________________ R2 (Color Code)=__________________ R2 (DMM):____________________ R3 (Color Code)=__________________ R3 (DMM):____________________ 21 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual b. Construct the circuit as shown in Figure 4.1. Calculate the total Resistance using formula 𝑅𝑇 = 𝑅1 + 𝑅2 + 𝑅3, Use lowest resistance as R1 and onward. 𝑅𝑇 = _______________Ω c. Now, connect DMM at point A & B and measure total resistance of the series circuit 𝑅𝑇 = _______________Ω Figure 4.1 Series Resistive Circuit d. Comments about the Resistance connected in series. 2. Circuit Voltage: Connect circuit as in fig. 4.2 and apply 15 VDC. a. Connect circuit in such way that R1 =1 kΩ, R2 = 2.2 kΩ. R3 = 3.3 kΩ. b. Calculate VR1 using voltage divider rule and measure VR1. Calculation (VDR) VR1(Calculated) =__________________ V VR1(measured) =___________________ V 22 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual c. Calculate VR2 using KVL and measure VR2. Calculation (KVL) VR2(Calculated) =__________________ V VR2(measured) =___________________ V Figure 4.2 Figure 4.3 d. Calculate VR3 using ohm’s law and measured VR3. Calculation (Ohm’s Law) VR3(Calculated) =__________________ V VR3(measured) =___________________ V Voltage Theory Measured Deviation VR1 VR2 VR3 R1 1kΩ R2 1kΩ R3 1kΩ V1 15 V A B C R1 1kΩ R2 1kΩ R3 1kΩ V1 15 V I1 0 A 25 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Experiment 5 Verification of KCL and Parallel Resistive Circuit 5.1 Objective The focus of this exercise is an examination of basic parallel DC circuits with resistors. A key element is Kirchhoff’s Current Law which states that the sum of currents entering a node must equal the sum of the currents exiting that node. The current divider rule will also be investigated. 5.2 Theory Overview A parallel circuit is defined by the fact that all components share two common nodes. The voltage is the same across all components and will equal the applied source voltage. The total supplied current may be found by dividing the voltage source by the equivalent parallel resistance. It may also be found by summing the currents in all of the branches. The current through any resistor branch may be found by dividing the source voltage by the resistor value. Consequently, the currents in a parallel circuit are inversely proportional to the associated resistances. 5.3 Equipment  DMM  Digital Trainer  Resistors 03 Nos: 1 kΩ, 2.2 kΩ. 3.3 kΩ , 6.8 kΩ 5.4 Procedure a) Using the circuit of Figure 5.1 with R1 = 1 kΩ, R2 = 2.2 kΩ and E = 8 V, determine the theoretical voltages at points A, B, and C with respect to ground. Record these values in Table 5.1. Then measure all voltage using DMM Table 5.1 Voltage Theoretical Measured VA VB VC 26 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Figure 5.1 b) Apply Ohm’s law to determine the expected currents through R1 and R2. Record these values in the Theory column of Table 5.2. Also determine and record the total current. Then measure current using DMM connecting in series to the resistor. Table 5.2 Current (mA) Theoretical Value Measured Value Deviation 𝐼𝑅1 = 𝑉1/𝑅1 𝐼𝑅2 = 𝑉2/𝑅2 𝐼𝑇 = 𝐸/𝑅𝑇 c) Consider the circuit of Figure 5.2 with R1 = 1 kΩ, R2 = 2.2 kΩ, R3 = 3.3 kΩ, R4 = 6.8 kΩ and E = 10 volts. Using the Ohm’s law, determine the currents through each of the four resistors and record the values in Table 5.3 under the Theory column. Note that the larger the resistor, the smaller the current should be. Also determine and record the total supplied current and the current Ix. Note that this current should equal the sum of the currents through R3 and R4. d) Set the DMM to measure DC current. Place the DMM probes in-line with R1 and measure its current. Record this value in Table 5.3. Also determine the deviation. Repeat this process for the remaining three resistors. Also measure the total current supplied by the source by inserting the ammeter between points A and B. 27 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Figure 5.2: Parallel Circuit Table 5.3 Current Theory Measured Deviation 𝑰𝑻 𝐼1 𝑈𝑠𝑖𝑛𝑛𝑔 𝑂ℎ𝑚′𝑠𝐿𝑎𝑤𝐼𝑇 = 𝐸 𝑅𝑇 =______________ 𝑰𝑹𝟏 𝐼1 𝑈𝑠𝑖𝑛𝑛𝑔 𝐶𝐷𝑅 𝐼𝑋 = 𝑅𝑇 𝑅𝑋 𝐼=__________________ 𝑰𝑹𝟐 𝐼2 𝑈𝑠𝑖𝑛𝑛𝑔 𝑂ℎ𝑚′𝑠𝐿𝑎𝑤𝐼𝑅2 = 𝑉2 𝑅2 =_____________ 𝑰𝑹𝟑 𝐼3 𝑈𝑠𝑖𝑛𝑛𝑔 𝑂ℎ𝑚′𝑠𝐿𝑎𝑤𝐼𝑅3 = 𝑉3 𝑅3 =_____________ 𝑰𝑹𝟒 𝐼4 𝑈𝑠𝑖𝑛𝑛𝑔 𝐾𝐶𝐿 𝐼𝑇 = 𝐼1 + 𝐼2 + 𝐼3 + 𝐼4=_______ 𝑰𝑿 𝐼𝑇 = 𝐼3 + 𝐼4=____________________________ e) To find Ix, insert the ammeter at point X with the black probe closer to R3. Record this value in Table 5.3 with deviation. 30 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual b) Which components make(s) up the network to be thevenized? ____________________________________________________ c) Calculate the value of RTH by removing the R3 = RL and short circuiting the voltage source. Show calculation work here: Rth = _____________________ Ω d) Calculate the value of VTH? Show calculation work here: Vth = _____________________ V e) Based on your calculated values of VTH and RTH, What is the load resistance (R3) current also measure the current through R3. Calculation for IR3 IR3(measured)=____________________ f) Connect R4 in parallel with RL to change the load, measure VRL and then calculate the Current through load now. Show calculation here 31 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual 2. Thevenizing a Dual Source Network a) Connect the circuit shown and apply VS1 and VS2. b) R2 is part of the network circuit. Calculate value of RTH? Show calculation work here: Rth = _____________________ Ω c) Short both voltages sources (while removing from the power supply) and measure RTH. Rth (measured)= _____________________ Ω d) Calculate the VTH1 and VTH2 and then VTH. Show calculation work here: 32 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual e) Place VS1 and VS2 back into your circuit. Measure VTH. Is the measured and calculated value about the same? f) Calculate and measure VRL and IRL. VRL = ____________________ IRL = ____________________ g) Draw the thevenin’s equivalent circuit and measure 35 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual 4. The peak to peak value of the voltage will be displayed on oscilloscope find its peak value. 5. Calculate the RMS value of this waveform. 6. Calculate the Average values of this waveform 7. Remove the oscilloscope probe and measure the voltage using DMM (selecting AC voltage measurement). 8. DMM measure which one value of the voltage. CONCLUSION  Oscilloscope measurement is taken from the top of a peak to the top of a valley to compensate for thickness of the trace.  The peak to peak value of an ac waveform is measured from a positive peak to a negative peak. The peak value s half of peak to peak value.  The rms value of a sine wave is 0.707 of the peak value.  The average value of a sine wave is 0.637 of the peak value Most multimeter displayed the rms value of an ac waveform 36 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Experiment 8 Determining the Capacitive Reactance in series RC Network OBJECTIVE At the completion of this unit, you will be able to determine the characteristics of resistive capacitive (RC) circuits by using an oscilloscope and given information. DISCUSSION  Capacitors pass ac current but present an opposition to current flow in the form of impedance. The impedance produced by a capacitor is referred to as capacitive reactance (XC) and is calculated using this equation. XC = 1 / (2πfC where XC is the reactance measured in ohms, f is frequency in hertz, C is capacitance in farads, 2 π is a constant that indicates that the equation is valid for sine waves only.  Capacitive reactance depends on the frequency of the signal and the capacitance.  Capacitive reactance and circuit capacitance are inversely proportional.  Capacitive reactance is independent of the amplitude of the applied signal. Equipment: Function Generator, Power Supply, DMM and Bread Board Components: Resistor (1.5kΩ) and Capacitor (0.22µF) PROCEDURE Part (A) Capacitive Reactance 1. Connect the circuit shown. Apply sinusoidal signal of 5 VPP @ 1 kHz. 2. Calculate XC for the various frequency signals like 500 Hz and 1, 2 KHz. 3. Measure the current passing through the series circuit. 4. Measure the Voltage across the capacitor using DMM. 5. Calculate XC using voltage and current formula. 1.5kΩ 220nF 4 Vpk 1kHz 0° 37 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Part (B) Series RC Circuits 1. Connect the circuit shown. 2. Measure the current flowing through the series circuit IRMS using DMM. 3. Calculate the rms value of the applied voltage. 4. Calculate the practical value of the circuit Impedance using Z = V /I. 5. Calculate the capacitive reactance. 6. Calculate the theoretical value of Impedance. CONCLUSION  Capacitive Reactance (Xc) can be calculated or measured.  Capacitive reactance depends on the value of capacitance and on the frequency of the applied signal.  Capacitive reactance is independent of the amplitude of the applied signal.  In a series RC circuit the circuit impedance is not equal to the sum of the total resistance (RT) and a capacitive reactance (XCT) but is equal to the square root of the sum of the square of (RT) and XCT  The circuit impedance of a series RC circuit is equal to the applied generator voltage divided by the total circuit current  The square root of the sum of the square of the voltage drops in a series RC circuit equals the amplitude of the applied signal 1.5kΩ 220nF 4 Vpk 1kHz 0° 40 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Figure 9.2: Forward and reverse biasing of diodes. 1. Measure the voltage across R1: VR1 = _________________ 2. Measure the voltage across R2: VR2= _________________ 3. Current flow Through D1 or D2? Explain Why? Connect the circuit as shown in figure below and adjust VA to positive 10 Vdc. 4. Measure the voltage across R1: VR1 = _________________ 5. Measure the voltage across R2: VR2= _________________ 6. Current flow Through D1 or D2? Explain Why? 7. Using Ohm’s law, find the current through R2: IR2= _________________ Perform the following steps to draw the characteristics of a diode 1. Disconnect the Diode D1. Adjust VA to -20 Vdc. 2. Note down the current ID through R2 and voltage across the diode (D2 here). 3. Complete the four columns of Table 2.1 by adjusting the VA accordingly. 41 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual 9.6 Lab Report A typeset (not hand-written), group lab report (not exceeding 5 pages including title page) is required and is due before 4pm one week after the lab. Submit report in the Lab. 9.7 Results Table 2.1: Current profile of the diode against different voltages. VA (Volts) VR2 ID2 VD2 ID2 = VR2 / R2 VD = VA – VR2 -20 -15 -10 - 5 0 0.25 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 2 5 7.5 10  Sketch a graph between VD and ID2.  Now verify measured results by completing the last columns of the above table computationally.  Plot the computed values of the VD and ID2 on the same graph. 42 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Experiment 10: Implementation of Half-Wave Rectifier Circuit 10.1 Objectives The objectives of this lab is: • to develop and analyze a half wave rectifier using a diode 10.2 Background Half-wave rectification converts an AC signal to a pulsating dc output. The circuit consists of a diode and a load resistance. Either positive or negative pulsating dc output can be produced, depending on the way the diode is connected to the circuit. Rectification is the process of converting ac to dc. Half-wave rectification occurs when conduction is for only one half of every ac cycle. DC output can be significantly lower than the ac input since the forward voltage drop of the diode must be reached before conduction occurs and voltage appears across the load. Half- wave rectification will be observed on an oscilloscope. Oscilloscope voltage measurements are peak-to-peak; therefore, the following conversion factor is used to convert the observed peak voltages to their corresponding average and rms values. For average voltage:  )(0 )(0 pk avg V V  For rms voltage: 2 )(0 )(0 pk rms V V  Variations in the pulsating dc output of a half-wave rectifier are referred to as ripple. Half-wave voltage rectifiers have ripple that is the same frequency as the input voltage frequency. The reverse recovery time (tRR) of the diode can have an adverse affect on the output of a half-wave rectifier at frequencies larger than 1 kHz. Reverse recovery time causes an output voltage pulse in a direction opposite that of the normal half-wave pulse. 10.3 Pre-Lab Read the lecture notes about the half wave rectification using diode. Calculate the output voltage theoretically using constant voltage drop model and draw waveform of the following circuits to compare it with the practical results. 10.4 Equipment • 2 Diodes 1N4007 45 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual 46 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Experiment 11: Implementation of Full-Wave Bridge Rectifier Circuit 11.1 Objectives The objectives of this lab is: • to develop and analyze a full wave bridge rectifier using diodes 11.2 Background A full-wave rectifier converts positive and negative alternations of an ac signal into a pulsating dc signal, as shown above. A full-wave bridge rectifier is a circuit that performs full-wave rectification. The input to the bridge rectifier circuit is usually the secondary coil of a power transformer. The transformer isolates the bridge rectifier from the ac source and serves to step up (increase) or step down (decrease) the ac input to the bridge rectifier. Diode bridges contain four diodes, designated D1 through D4, configured so that two diodes conduct during each half-cycle of the input ac signal and produce a pulsating dc output. The pulsating dc output flows through the load resistance in one direction, independent of which ac cycle the current is derived. Two input terminals, usually labeled with a sine wave symbol, and two output terminals, labeled with positive and negative symbols, are present on the bridge rectifier. Diodes D1 and D3 are forward biased during the positive half-cycle of the ac input signal. Diodes D2 and D4 are forward biased during the negative half-cycle of the ac input signal. Each diode pair conducts for one half-cycle of the ac input signal, resulting in full-wave rectification. Since there are two dc pulses for one complete cycle of the input ac waveform, the output pulse frequency of a full-wave rectifier is twice the ac input frequency. The following relationships apply to full-wave diode bridge rectifiers. Peak output voltage (Vo(pk)) equals the peak input voltage (Vi(pk)) minus the forward voltage drop (VF) of the two conducting diodes.  Vo(pk) = Vi(pk) − 2VF Output rms voltage (Vo(rms) ) equals 0.707 times the peak output voltage.  Vo(rms) = 0.707 x Vo(pk) 47 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Output average (Vo(avg)) voltage equals 0.636 times the peak output voltage.  Vo(avg) = 0.636 x Vo(pk) 11.3 Procedure 1. Connect the circuit as shown in figure below. 2. Adjust the generator for a 20 Vpp, 100 Hz Sine wave at the T1 secondary coil. 3. Compare the transformer secondary peak to peak voltage with primary voltage and check that both signals are inphase. 4. Use the step up transformer that adjusts secondary voltage of 20 voltage when primary voltages are 16 peak to peak voltages. 5. Observe the output across R1 by connecting the oscilloscope probe on the (+) output test point of the bridge rectifier. 6. Measure the frequency of the dc output pulsations across the load resistor R1. f=_____________ Hz 7. Measure the peak dc out put voltage. VO(p)= _________________ 8. Find the conduction angle, fraction of a cycle for which each diode conducts, Vavg and Iavg. Verify your results experimentally. Conduction Angle = _____________ Fraction of a Cycle = _____________ Vavg = _____________ Iavg = _____________ 9. Now measure the dc voltage using DMM. VO(avg)= _________________ 10. What is difference between transformer secondary coil voltage and output voltage? State the reason of difference? 11. During the positive and negative half cycle of the wave form observe the output across D2. 12. Draw the wave form of voltage that you observe on oscilloscope of input and across D2. 50 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual 12.3 Design  Design a 5 V DC regulated power supply to deliver up to 1A of current to the load with 5% ripple. o The input supply is 50Hz at 230 V AC.  Selection of Voltage regulator IC: Fixed voltage linear IC regulators are available in a variation of voltages ranging from - 24V to +24V. The current handling capacity of these ICs ranges from 0.1A to 3A. Positive fixed voltage regulator ICs have the part number as 78XX. The design requires 5V fixed DC voltage, so 7805 regulator IC rated for 1A of output current is selected.  Selection of Bypass Capacitors: The data sheet on the 7805 series of regulators states that for best stability, the input bypass capacitor should be 0.33µF. The input bypass capacitor is needed even if the filter capacitor is used. The large electrolytic capacitor will have high internal inductance and will not function as a high frequency bypass; therefore, a small capacitor with good high frequency response is required. The output bypass capacitor improves the transient response of the regulator and the data sheet recommends a value of 0.1µF.  Dropout voltage The dropout voltage for any regulator states the minimum allowable difference between output and input voltages if the output is to be maintained at the correct level. For 7805, the dropout voltage at the input of the regulator IC is Vo +2.5 V. Vdropout = 5 + 2.5 = 7.5V  Selection of Filter Capacitor: The filter section should have a voltage of at least 7.5V as input to regulator IC. That is Vdc = 7.5 V 51 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual  Selection of Diodes: 1N4007 diodes are used as it is capable of withstanding a higher reverse voltage, PIV of 1000V whereas 1N4001 has PIV of 50V.  Selection of Transformer: Maximum unregulated voltage, Vunreg(max) = Vdropout + Vr = Two diodes conduct in the full-wave bridge rectifier, therefore peak of the secondary voltage must be two diode drops higher than the peak of the unregulated DC. Vsec(peak) = Vunreg(max) + 1.4V = ___________________ Vsec(rms) = 0.707 x Vsec(peak) = _______________________ The power supply is designed to deliver 1A of load current, so the secondary winding of the transformer needs to be rated for 1A. 52 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual 12.4 Circuit Diagram 12.5 PRACTICE PROCEDURE 1. Connect the circuit as shown in Figure 2. 2. Apply 230V AC from the mains supply. 3. Observe the following waveforms using oscilloscope 55 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual DISCUSSION The emitter terminal is common to both the input and output signals. Base voltage (VB) can be calculated from the voltage divider equation. Ohm’s law is used to calculate the emitter current (IE). The emitter current and collector current (IC) are nearly equal. The exact collector current can be found by subtracting the base current from the emitter current. Current gain is the ratio of dc collector current to base current. Dc current gain is represented by beta (βdc) or hFE and usually ranges in value between 10 and 500. Design criteria for a common emitter circuit specify a collector voltage (VC) about halfway between the power supply voltage (VA) and the emitter voltage (VE). The saturation point occurs when the collector-emitter voltage (VCE) is zero and collector current is maximum (IC(SAT)). Cuff off occurs when collector current is approximately zero. The area on a transistor characteristic curve between saturation and cutoff is called the active region. The Q-point of a transistor is determined by its dc bias conditions. Q-point is the where the dc load line intersects the base current, collector current, and the collector-emitter voltage Curves. The ideal location of the Q-point is at the midpoint of the dc load line. PROCEDURE 19. Connect the circuit as shown in figure. 20. Adjust Supply Voltage to 15 Vdc. 21. Calculate the base voltage (VB) of Q1. VB = (VA) (R2 / R1+ R2) 22. Measure the base voltage with reference to the ground. 23. Does your measured and calculated values agreed. 24. Measure Collector Voltage (VC) 25. Measure the emitter voltage (VE) with reference to ground. 26. Do your measured values indicate that base emitter junction is forward bias and base collector junction is reverse biased? 56 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual 27. Is the transistor operating in its active region? 28. Calculate the dc emitter current. IE = VE / R5 29. Calculate the Collector current. IC = (VA - VC) / R4 30. Are the emitter and collector currents are essentially the equal? 31. The operating point, or Q-point, is determined by the dc bias conditions of the transistor. Using the voltage measured previously what is VCE. 32. Sketch the dc load line graph. (the graph will be between IC & VCE) 33. What is the value of VCE (Cutt Off)? 34. What is the IC(sat) Saturation? 35. Is the transistor properly biased CONCLUSION  A voltage divider circuit provides a constant dc base voltage that properly biased the transistor.  The emitter current is the sum of base and collector currents.  Because the base current is very small, the emitter and collector currents are essentially the equal  For proper transistor operation is the active region, the base emitter junction is forward biased, and the base collector junction is reverse biased.  The dc load line describes the relationship between the collector current and the collector- emitter voltage difference.  The Q-point on the dc load line is at the intersection of the operating collector current and the collector emitter voltage.  The intersection of the dc load line and y-axis is the saturation point; the intersection of the dc load line and x-axis is the cut-off point (Zero currents). 57 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Experiment 14: BJT Common Emitter Characteristics Objectives To plot the characteristics curves of a BJT transistor in Common Emitter (CE) configuration. Background At the completion of this experiment, you will be able to test transistors and demonstrate a transistor switch by using PNP and NPN transistor circuits. When you have completed this exercise, you will be able to test a transistor by forward biasing and reverse biasing the junctions. When another section of P or N type material is added to a PN diode junction, a three-section device containing two junctions is formed. This three-section semiconductor device is a bipolar transistor. The three sections are the emitter (E) and collector (C) on the ends and the base (B) in the middle. Transistors are classified by the arrangement of the P (positive) and N (negative) type materials. Transistors are either PNP or NPN types, as shown. Each of the two PN junctions of a transistor has forward and reverse voltage/current characteristics similar to a diode PN junction. Q is the letter used to identify a transistor. The emitter arrows in the NPN and PNP transistor symbols show the direction of conventional current flow. Electron current flow, which is in the opposite direction of conventional current flow, is used in this course. 60 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Lab Report A typeset (not hand-written), group lab report (not exceeding 5 pages including title page) is required and is due before 4pm one week after the lab. Submit report in the DEE office. Results S.no. VCE VBE = 0.5V . IB = ______ VBE = 0.6V . IB = ______ VBE = 0.7V . IB = ______ VBE = 0.75V . IB = ______ IC IC IC IC 1 0.0 2 0.25 3 0.5 4 1.5 5 2.0 6 2.5 7 3.0 8 3.5 9 4.0 10 4.5 11 5.0 12 5.5 13 6.0 14 8.0 15 10.0 16 12.0 61 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Experiment 15-16: Applications of Operational Amplifier Objectives To study the Operational amplifier as inverting, non-inverting, Adder, Subtractor and Comparator Background Components and Equipments required: IC741, Regulated DC power supply (2), Resistors (10 k, 1k, ) Multimeter, Signal generator, Oscilloscope, Bread board and connecting wires. Theory: The Operational amplifier (Op-amp) is a high gain, direct coupled, differential amplifier with high input resistance & low output resistance. It is named so as it can be used to perform a number of mathematical operations, like addition, subtraction, comparison etc.  A circuit in which the output voltage is sum of the inputs is called an adder.  A circuit in which the output voltage is difference between the inputs is called a subtractor.  A circuit which compares an input with a reference voltage is called a comparator.  A circuit in which the output voltage is the same as the input is called a non-invertor.  A circuit in which the output voltage is inverted is called an invertor. Task 1: Inverting Amplifier Configuration  Connect the circuit as shown in figure. 62 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual  Apply the +12V VCC and -12V VEE at 7th and 4th terminal respectively.  Apply input ac signal of 3VP at inverting terminal.  Observed the input and output waveform on oscilloscope.  Derive the voltage gain formula and calculate it. Task 2: Non Inverting Amplifier Configuration  Connect the circuit as shown in figure.  Apply the +12V VCC and -12V VCE at 7th and 4th terminal respectively.  Apply input ac signal of 3VP at non inverting terminal.  Observed the input and output waveform on oscilloscope.  Derive the voltage gain formula and calculate it. Task 3: Inverting Adder Configuration U1 LM741H 3 2 4 7 6 51 R1 1kΩ Rf 1kΩ VCC 12V VEE -12V V1 2.12 Vrms 1kHz 0° U1 LM741H 3 2 4 7 6 51 R1 1kΩ Rf 1kΩ VCC 12V VEE -12V V1 2.12 Vrms 1kHz 0° 65 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual 14.4 Result: Complete the following table for each of the above tasks 66 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Annex-I PIEAS Vision Statement It is the vision of PIEAS to be recognized at the national and international level as an Institute of academic excellence with high moral and ethical values, providing synergy between scientific research and technological development for national security and socio-economic benefits, encouraging and fostering an environment of mutual respect and free exchange of thoughts, where lack of resources on part of deserving students is not an impediment to acquiring quality education. PIEAS Mission Statement PIEAS is committed to excellence in science and engineering education. We seek to impart education in fields which are essential for the technological development of Pakistan and, in particular, to play a pioneering role in fostering the establishment of educational programs in newly emerging technological fields in the country. We accord the highest priority to meeting the current and future trained manpower needs of PAEC and other technical organizations. We aim to provide a learning environment that fully stimulates the students' intellectual capabilities and also nurtures their personal development as future technological leaders. We are committed to ensuring the highest quality in all our endeavors, encompassing teaching, research, skills and developmental activities through an effective overarching quality enhancement framework. 67 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual Program Learning Outcomes (PLOs)  PLO1. Engineering Knowledge: An ability to apply knowledge of mathematics, science, engineering fundamentals and an engineering specialization to the solution of complex engineering problems.  PLO2. Problem Analysis: An ability to identify, formulate, research literature, and analyze complex engineering problems reaching substantiated conclusions using first principles of mathematics, natural sciences and engineering sciences.  PLO3. Design/Development of Solutions: An ability to design solutions for complex engineering problems and design systems, components or processes that meet specified needs with appropriate consideration for public health and safety, cultural, societal, and environmental considerations.  PLO4. Investigation: An ability to investigate complex engineering problems in a methodical way including literature survey, design and conduct of experiments analysis and interpretation of experimental data, and synthesis of information to derive valid conclusions.  PLO5. Modern Tool Usage: An ability to create, select and apply appropriate techniques, resources, and modern engineering and IT tools, including prediction and modeling, to complex engineering activities, with an understanding of the limitations.  PLO6. The Engineer and Society: An ability to apply reasoning informed by contextual knowledge to assess societal, health, safety, legal and cultural issues and the consequent responsibilities relevant to professional engineering practice and solution to complex engineering problems.  PLO7. Environment and Sustainability: An ability to understand the impact of professional engineering solutions in societal and environmental contexts and demonstrate knowledge of and need for sustainable development.  PLO8. Ethics: Apply ethical principles and commit to professional ethics and responsibilities and norms of engineering practice.  PLO9. Individual and Team Work: An ability to work effectively, as an individual or in a team, on multifaceted and /or multidisciplinary settings.  PLO10. Communication: An ability to communicate effectively, orally as well as in writing, on complex engineering activities with the engineering community and with society at large, such as being able to comprehend and write effective reports and design documentation, make effective presentations, and give and receive clear instructions.  PLO11. Project Management: An ability to demonstrate management skills and apply engineering principles to one’s own work, as a member and/or leader in a team, to manage projects in a multidisciplinary environment.  PLO12. Lifelong Learning: Ability to recognize importance of, and pursue lifelong learning in the broader context of innovation and technological developments. 70 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual CL O No. Criterion (Points) 1 (Very Weak) 2 (Weak) 3 (Moderate) 4 (Strong) 5 (Very Strong) 2 Design (20 Points)  Unable to design the required circuit  Can perform required calculations and design circuit with errors  Can perform required calculations and design circuit  Perform required calculations, design and analyze circuit with minor omissions  Preform required calculations, design and analyze the required circuit Data Collection (20 Points)  Measurement s are incomplete, inaccurate and imprecise  Observations are incomplete or not included  Measurement s are somewhat inaccurate and very imprecise  Observations are incomplete or recorded in a confusing way  Measurement s are mostly accurate  Observations are generally complete  Work is organized  Measurement s are accurate with reasonable precision  Observations are thorough  Measurement s are both accurate and precise  Observations are very thorough and may recognize possible errors in data collection Safety (5 Points)  Proper safety precautions are consistently missed  Proper safety precautions are often missed  Proper safety precautions are generally used  Proper safety procedures are consistently used  Proper safety precautions are consistently used Clean-up (5 Points)  Proper clean- up procedures are seldom used  Needs to be reminded about proper clean-up procedures and 1 or 2 items left at station or not cleaned  Proper clean- up procedures generally used, and station generally left clean  Consistently uses proper clean-up procedures and station generally neat and clean  Consistently uses proper clean-up procedures, and station always left neat and clean 3 Title, Abstract & Introductio n (5 Points)  Title, abstract or introduction is missing  Incorrect title with missing information  Abstract does not include all key points  Incorrect title with no missing information  Abstract includes some key points  Correct title with missing information  Abstract includes all key points with mistakes  Correct title with no missing information  Abstract includes all key points 71 | P a g e EE-153 Introduction to Electrical Engineering Lab Manual CL O No. Criterion (Points) 1 (Very Weak) 2 (Weak) 3 (Moderate) 4 (Strong) 5 (Very Strong)  Introduction not complete  Introduction incomplete  Introduction is complete but has mistakes and properly written Experiment Procedure (5 Points)  No steps are listed  Most steps are listed incorrectly, unclearly, or in wrong order  Most steps are listed clearly, in wrong order  Most steps are listed clearly, in correct order  All steps are listed clearly, in correct order Results & Discussion (10 Points)  Results are incompletely discussed and interpreted incorrectly  Results are incompletely discussed and interpreted mostly correctly  Results are mostly discussed and interpreted mostly correctly  Results are discussed and interpreted mostly correctly  Results are discussed and interpreted correctly Report Format (10 Points)  Report has serious spelling, formatting, and grammar mistakes  Multiple sections of the lab report are missing  Symbols, units and significant figures are not included  Rubric sheet is not attached  Report has many spelling, formatting, and grammar mistakes  Many sections of the lab report are missing  There are 3 or more minor errors using symbols, units and significant digits or 2 major errors  Rubric sheet is not attached  Report has some spelling, formatting or grammatical errors  All parts are present but not in correct order  Only 2 or 3 minor errors using symbols, units and significant digits  Rubric sheet is attached  Report is typed but has few spelling, formatting or grammatical errors  All parts are present but some are not in correct order  Includes symbols, units and significant digits  Rubric sheet is attached  Report is typed with good spelling, formatting, and grammar  All parts of lab report are present in correct order  Includes appropriate symbols, units and significant digits  Rubric sheet is attached