ELE 404 Electronics I Introductory Lab PDF

Toronto Metropolitan University Department of Electrical, Computer and Biomedical Engineering ELE 404: Electronics I Introductory Lab Introduction The main objective of this lab is to help you acquaint yourself...

Toronto Metropolitan University Department of Electrical, Computer and Biomedical Engineering ELE 404: Electronics I Introductory Lab Introduction The main objective of this lab is to help you acquaint yourself with the labs in ELE404, in terms of their structure, nature of preparation required, and equipment. The lab will refresh you on one of the most effective circuit analysis techniques, namely, the superposition technique, albeit from a standpoint that you have probably not seen before. Furthermore, this lab will also set the stage for teaching the concept of capacitive coupling of AC signals with DC circuits. It is highly recommended that you carefully study the Appendix of this manual, for a quick overview on the equipment you will be using regularly in this series of labs. PRE-LAB ASSIGNMENT P1. Consider the circuit of Figure 1. Assume that the capacitor is short for AC signals and open for DC signals. Also, assume that voltage 𝑣𝑆 in Figure 1 is a 20-kHz sinusoid with a peak-to-peak swing of 4.0 V (or, equivalently, with an rms value of 1.41 V). Thus, let 𝑣𝑆 (𝑡) = 2sin⁡(𝜔𝑡), where 𝜔 = 2𝜋 × 20,000⁡𝑟𝑎𝑑/𝑠. Then, use the “superposition” principle to manually find the waveforms of voltages 𝑣𝐼 and 𝑣𝑂 (i.e., the time functions 𝑣𝐼 (𝑡) and 𝑣𝑂 (𝑡)). Use Matlab or Excel to plot your expressions for 𝑣𝐼 (𝑡) and 𝑣𝑂 (𝑡), for two cycles (periods), and present the result as Graph P1. Also, complete Table P1 based on your calculations. See the Reminder below. Show all work. Hint Superposition can be exercised in various ways. For example, one way would be to consider the response of a circuit as the sum of the response due to the AC sources (while the DC sources are “off”) and the response due to the DC sources (while the AC sources are “off”). Remember that, regardless of AC or DC, an “off” voltage source means a short link, whereas an “off” current source means an open circuit. Last Updated: Jan. 23, 2018-AY 1  VCC 5.0 V R1 Rs R3 C1 3.9kΩ 600Ω 2.2kΩ 100nF + + FIGURE 1 vS vI R2 vO 10kΩ - - -5.0 V -VCC Figure 1. A circuit involving both AC and DC voltages. Reminder The “DC” value (also known as the “average” or “mean”) ofVaCC periodic waveform 𝑣(𝑡) is defined by the following integral: 5.0 V Signal Generator 𝑇 R1 Rs 1 𝑉𝑑𝑐 = ∫ 𝑣(𝜏)𝑑𝜏 3.9kΩ 600Ω 𝑇 𝜏=0 + + FIGURE 3 where 𝑇 is the period of the waveform. All meters in their DC measurement vO mode display the DC vS vI or average value of the incoming signal. R2 10kΩ - - The “rms” value of 𝑣(𝑡), is defined by the following integral -5.0 V 𝑇 -VCC 1 𝑉𝑟𝑚𝑠 = √ ∫ 𝑣 2 (𝜏)𝑑𝜏 𝑇 𝜏=0 which is the square rootSignal average of the square of the waveform! Modern of theGenerator R1 meters in their AC measurement mode display the Rsrms value R3 of the incoming signal, 3.9kΩ as defined by the above integral. A very famous special 600Ω case, which2.2kΩ is often incorrectly generalized, is that of a sinusoidal waveform: The rms value of a sinusoid is Vrms = Vm /√2, where Vm is the peak value of the sinusoid. + + FIGURE 4 vS also capablevofI doing the so-called AC+DC Many modern meters are 2 R vO measurements. In its AC+DC 10kΩ - - measurement mode, a meter can calculate the rms value of a waveform that consists of a DC component and an AC component. Thus, the meter displays the following: 2 2 𝑉𝑅𝑀𝑆 = √𝑉𝑑𝑐 + 𝑉𝑟𝑚𝑠 VCC where: 5.0 V 𝑉𝑑𝑐 : The DC (average) component of 𝑣(𝑡), which the meter displays in its DC measurement mode 𝑉𝑟𝑚𝑠 : The rms value ofSignal Generator the AC R1 component of 𝑣(𝑡), which the meter displays in its AC measurement mode Rs R3 C1 3.9kΩ Introductory Lab 600Ω 100nF 2 2.2kΩ +  𝑉𝑅𝑀𝑆 : The rms value of 𝑣(𝑡) as a whole, which the meter displays in its AC+DC measurement mode In the discussion above, we used 𝑣(t) to symbolize a signal. However, the discussion applies to any signal in general, irrespective of its physical nature, voltage, current, etc. vI t vO t Graph P1. Waveforms of 𝒗𝑰 and 𝒗𝑶 , for the circuit of Figure 1. Table P1(corresponding to Figure 1) 𝑣𝑆 (p-p) 𝑣𝐼 (rms) 𝑣𝐼 (dc) 𝑣𝑂 ⁡(rms) 𝑣𝑂 ⁡(dc) 𝑣𝑂 (RMS) 4V EXPERIMENTS AND RESULTS E1. Start by constructing the circuit of Figure 2, which consists of two independent sub-circuits, i.e., sub-circuit (a) and sub-circuit (b), as Figure 2 indicates. Your signal generator (also known as the “function generator”) has a built-in (or Thevenin equivalent) resistance of 50 Ω, while we need a source resistance, 𝑅𝑆 , of 600⁡Ω, as Figure 2 illustrates. Therefore, to achieve a source resistance of 𝑅𝑠 = 600⁡Ω, place a 560-Ω resistor in series with the output of the signal generator (and do not worry about the extra 10 ohms!). Thus, consider the original signal generator and your added 560-Ω resistor as the signal generator that the circuit of Figure 2 is calling for. Figure 3 illustrates the concept. V CC Introductory Lab VD D 3 R3 v  -VCC vI R2 vO 10kΩ - - VCC 5.0 V Signal V Generator CC R1 5.0 V Rs 3.9kΩ 600Ω Generator R1 + Rs R3 C1 3.9kΩ + Figure 3 600Ω 2.2kΩ 100nF vS vI R2 vO 10kΩ + +- Figure 5 - vI R2 vO -5.0 V 10kΩ - - -VCC -5.0 V (a) (b) -VCC Figure 2. Circuit for Step E1. Augmented Signal Generator Signal Generator nal Generator Original R1 R sSignal Generator R3 from 3.9kΩ your Rs 600Ω 2.2kΩ lab kit 600Ω + 50Ω 560Ω + Figure 4 + vS vI R2 vO vI + 10kΩ S vS - vI - - - VCC for the circuit of Figure 2. Figure 3. Implementation of the signal generator 5.0 V Set the signal generator to produce a 20-kHz symmetrical sinusoidal voltage with a magnitude of 4 V peak-to-peakSignal asGenerator its Thevenin equivalent voltage 𝑣𝑆R. 1However, since you cannot have access to 𝑣𝑆 , you must achieve R3 C R s the aforementioned 1 goal by monitoring/measuring 3.9kΩ the terminal voltage 𝑣𝐼. Thus, monitor600Ω 2.2kΩ 100nF 𝑣𝐼 by your oscilloscope and set your signal generator to produce a 20-kHz symmetrical sinusoidal voltage with a magnitude of 4 V peak-to-peak (see the “Tips”, below). Note that, since nothing +other than the oscilloscope probes + is connected Figureto 5 the output of the signalv S generator at v R 2 v O I this stage, you are, in effect, setting 𝒗𝑺 through the 10kΩ aforementioned exercise. - - Next, using the multimeter, measure the following quantities -5.0 Vand complete Table E1: -VCC The rms value of the AC component of 𝑣𝐼 (multimeter in the AC voltage measurement mode) The DC value of 𝑣𝐼 (multimeter in the DC voltage measurement mode) The rms value of the AC component of 𝑣𝑂 (multimeter in the ACAugmented Signal Generator voltage measurement mode) 𝑣𝑂 (multimeter The DC value ofSignal Generator in the DC voltage measurement mode) Original The rms value of 𝑣𝑂 as a whole, that is including its DC and AC components Signal Generator from your (multimeter in the R s AC+DC voltage measurement mode) lab kit 600Ω 50Ω 560Ω Introductory Lab + vS vI +4 vS vI  VCC 5.0 V Tips R1 Rs R3 C1 3.9kΩground. The voltages must be measured 600Ω with2.2kΩreference to the (common) 100nF Connect Channel 1 of the oscilloscope to 𝑣𝐼 and also use it as the trigger source for the oscilloscope. Set Channel 1 to the + DC-coupled mode, with a voltage +sensitivity of Figure 1 V/div; 1 set the oscilloscopevtime-base to 10 S vIµsec/div. R2 vO For each measurement, ensure the multimeter is in the suitable 10kΩcorresponding mode. - - Table E1 (corresponding to Figure 2) -5.0 V 𝑣𝑆 (p-p) 𝑣𝐼 (rms) 𝑣𝐼 (dc) 𝑣𝑂 ⁡(rms) 𝑣𝑂 ⁡(dc) 𝑣𝑂 (RMS) -VCC 4V E2. Change the circuit of Figure 2 to that of Figure 4. Make sure that you disconnect the DC power supply from the circuit, and connect the uncommon V terminals CC of 𝑅1 and 𝑅2 (which were connected to the power supply lines 𝑉𝐶𝐶 and – 𝑉𝐶𝐶 ) to theVground by two short wires. Also, 5.0 before inserting 𝑅Signal 3 intoGenerator the circuit, make sure that 𝑣𝐼 has the same peak-to-peak swing (i.e., 4 R 1 the oscilloscope, capture the V) and frequency (i.e., 20 kHz) as those it had in Step E1. Using waveforms of 𝑣𝐼 and 𝑣𝑂 for two R s 3.9kΩ cycles. Using the USB utility of the oscilloscope, save the two 600Ω captured waveforms as Graph E2. Note that the amplitude of 𝑣𝐼 decreases once the resistor 𝑅3 is inserted into the circuit. + + Figure 3 v S I v R2 vO Using the multimeter, measure and record the quantities indicated 10kΩ in Table E2. - - Tips Connect Channel 1 of the oscilloscope to 𝑣𝐼 and Channel-5.0 V2 to 𝑣𝑂 , and use Channel 1 as the trigger source for the oscilloscope. Set both channels-V toCCthe DC-coupled mode, with voltage sensitivities of 1 V/div (for Channel 1) and 1 V/div (for Channel 2); set the oscilloscope time- base to 10 µsec/div. Signal Generator R1 Rs R3 3.9kΩ 600Ω 2.2kΩ + + Figure 4 vS vI R2 vO 10kΩ - - Figure 4. Circuit for Step E2. VCC 5.0 V Table E2 (corresponding to Figure 4) 𝑣𝑆 (p-p) Signal (rms) 𝑣 Generator 𝐼 𝑣𝐼 (dc) 𝑣𝑂 ⁡(rms) R1 𝑣𝑂 ⁡(dc) 𝑣𝑂 (RMS) Rs R3 C1 3.9kΩ 4V 600Ω 2.2kΩ 100nF Introductory Lab + + Figure 5 5 vS vI R2 vO 10kΩ  Signal Generator R1 Rs R3 3.9kΩ 600Ω E3. Change the circuit of Figure 2.2kΩ 4 to that of Figure 5 and repeat experiment E2. Thus, reconnect the power supply lines to the circuit. First take 𝑅3 out and, once again, make sure that 𝑣𝐼 has + the same peak-to-peak swing and frequency as those it had in E1 (i.e., 4 + Figure 4 V and 20 kHz). vS vI R2 vO 10kΩ - multimeter, measure and record the quantities indicated in Table E3. - Capture the waveforms of 𝑣𝐼 and 𝑣𝑂 for two cycles, and save them as Graph E3. Using the Tips Same as those for E2. VCC 5.0 V Signal Generator R1 Rs R3 C1 3.9kΩ 600Ω 2.2kΩ 100nF + + Figure 5 vS vI R2 vO 10kΩ - - -5.0 V -VCC Figure 5. Circuit for Step E3. Augmented Signal Generator Signal Generator Original Signal Generator from your Table E3 (corresponding toRFigure s 5) lab kit 𝑣𝑆 (p-p) 𝑣𝐼 (rms)600Ω 𝑣𝐼 (dc) 𝑣𝑂 ⁡(rms) 𝑣𝑂 ⁡(dc) 𝑣𝑂 (RMS) 50Ω 560Ω 4V + vS vI + vS vI - - CONCLUSIONS AND REMARKS C1. Compare the results of Table P1 and Table E3, and comment on the reasons for discrepancies, if any. Do the results agree with the equation presented in Part P1 for the rms value of a composite signal? C2. Justify the waveform of 𝑣𝑂 in E3, based on the principle of “superposition” and what you observed in experiments E1 and E2. C3. Using Multisim or any other circuit simulation software, simulate the circuit shown in Figure 1 (which is the same as the circuit in Figure 5), based on the assumption that the voltage 𝑣𝑆 is a 20-kHz sinusoidal signal with a peak-to-peak swing of 4 V. In the lab report, attach the resulting simulated waveforms for 𝑣𝑆 , 𝑣𝐼 , and 𝑣𝑂 , all plotted on one single frame and labeled clearly. Additionally, include the schematic diagram of the simulated circuit by printing from the screen in Multisim. Compare the waveforms obtained from the simulation with those of Graph E3, and comment. Introductory Lab 6 Appendix—INTRODUCTION TO EQUIPMENT Digital Multimeter A1. The digital multimeter (or simply, the multimeter) is a multi-purpose instrument whose main function is to measure AC and DC voltages, AC and DC currents, and resistance. Most modern multimeters, however, can also measure capacitance, signal magnitudes in dB, frequency, connectivity, and much more. You have two Fluke 45 digital multimeters at your workstation. Examine your multimeter and familiarize yourself with the following: Different major functions that the multimeter can perform The way the multimeter must be set up for measuring voltages, small currents (in the range of mA), and resistances The way the multimeter must be set up for DC and AC measurements Breadboard A2. The breadboard, also called the prototyping board, offers a convenient way for rapid prototyping of simple electronic circuits. Figure 6 shows the top view of a typical breadboard. As the figure shows, the breadboard has many tapered holes (receptacles) that are connected in groups to corresponding metallic strips which are enclosed and insulated from each other by a milky plastic enclosure. Thus, thin wires and pins of small electronic components can be inserted into the holes to make electrical connection with other components. As Figure 6 shows, the breadboard shown here has four horizontal rows of holes, two at the top and two at the bottom. Thus, the rows are paired and marked with a blue line and a minus sign, and with a red line and a plus sign. In each of these rows, the holes are interconnected, but isolated from those of the other rows. These rows are commonly used as power supply and ground bars for the circuit. Figure 6 also shows that the breadboard has two sets of vertical columns, each with 5 holes, which are separated from each other by a trench. Thus, the holes in each column are interconnected, but isolated from those of the other columns (and rows). The columns, numbered in the breadboard of Figure 6 from 1 to 63, are commonly used to establish connections between circuit components as well as Integrated Circuits (ICs) in a Dual In-Line Package (DIP). For example, the breadboard of Figure 6 hosts a 14-pin chip (ALD1106) and an 8-pin chip (LF411CN). In particular, pin 1 of ALD1106 is connected to holes A-15, B-15, C-15, D-15, and E-15, whereas pin 14 is connected to F- 15, G-15, H-15, I-15, and J-15, and so on. Figure 7 summarizes the foregoing description by illustrating that the holes within each rectangle are interconnected, but isolated from the other holes. It should be pointed out that more sophisticated packages of breadboards are commercially available. Figure 8 shows an example where two breadboards are installed on a metallic back plate furnished with power supply receptacles. Examine your breadboard. Using the multimeter in the “connectivity check” mode and two small pieces of wire connected to its probes, check the following: Interconnectivity of the holes of a row or a column; and Connectivity of the holes of a row or column to those of another row or column. Introductory Lab 7  Figure 6. Top view of the breadboard. Figure 7. Picture showing the groups of interconnected holes. Figure 8. Two breadboards installed on a metallic back plate with power supply receptacles. Introductory Lab 8 Bench-Top Power Supply A3. The power supply has three ports. Two of the ports have a common ground and thus provide positive and negative potentials with respect to the ground. The third port, however, is isolated from the other two. All three ports are isolated from the power line earth. You have one E3630A power supply on your desk. Examine the power supply and identify the following: The maximum voltage and current available at each port The ground terminal of the power supply Oscilloscope A4. The oscilloscope is an instrument for monitoring waveforms and signals. It has more than one channel (up to 4) and can thus be used for simultaneous monitoring of multiple signals. The oscilloscope can also plot signals against one another (the X-Y mode). You have one KEYSIGHT DSOX1102G oscilloscope on your desk. Examine the oscilloscope in order to become familiar with the: Probes and their BNC connectors Screen and its grid Vertical voltage-per-division and time-per-division (time-base) controls Vertical and horizontal position controls DC and AC signal coupling modes and their control Trigger source and level controls Signal Generator (Function Generator) A5. The signal generator is an instrument that can produce time-varying signals of different shape, magnitude, and frequency. You have one GW-Instek GFG-8216A signal generator on your desk. Examine the signal generator provided at the workstation and become familiar with the: Output connectors and cable Waveform selection buttons Amplitude and frequency controls DC offset control Introductory Lab 9 TA Copy of Results Table E1 (corresponding to Figure 2) 𝑣𝑆 (p-p) 𝑣𝐼 (rms) 𝑣𝐼 (dc) 𝑣𝑂 ⁡(rms) 𝑣𝑂 ⁡(dc) 𝑣𝑂 (RMS) 4V Table E2 (corresponding to Figure 4) 𝑣𝑆 (p-p) 𝑣𝐼 (rms) 𝑣𝐼 (dc) 𝑣𝑂 ⁡(rms) 𝑣𝑂 ⁡(dc) 𝑣𝑂 (RMS) 4V Table E3 (corresponding to Figure 5) 𝑣𝑆 (p-p) 𝑣𝐼 (rms) 𝑣𝐼 (dc) 𝑣𝑂 ⁡(rms) 𝑣𝑂 ⁡(dc) 𝑣𝑂 (RMS) 4V Data Set-Up Participation Partner’s Name Collection (out of 10) (out of 5) (out of 10) 1 2 Introductory Lab 10