Assignment /01

Transcription

1 Principles and Applications of Electronic Devices and Circuits Assignment /01 It's very straightforward to submit this test paper online by logging on to the ICS Student Community at For guidance on submitting test papers online, please see the Help>Assessment section of the Student Community. Evidence you need to provide from this unit: 1 Written reports where requested. 2 Photographs where requested, with you in the picture. 3 Video footage of your circuits being built. Video must show you in the video. 4 Video footage of your circuits being tested. Video must show you in the video. You will find a table showing the assessment criteria for this unit at the end of the assessment tasks A 141

2 BTEC Level 3 Certificate in Electronic Engineering Task 1 Principles and Applications of Electronic Devices and Circuits: Analogue Circuits The Assignment Criteria for this task are: P1 Explain the purpose of two different types of diode, each in a different electronic circuit application P2 Explain the operation of two different types of transistor, one in an analogue and one in a digital circuit M1 Modify an existing analogue circuit to achieve a given revised specification by selecting and changing the value of one of the components (merit criterion). Context Your employer is developing a new battery-powered product, one which requires a 6 V supply and an LED operated by a digital circuit. You are required to construct and test two analogue circuits. One is a voltage regulator using a Zener diode for stabilisation. The other is a transistor wired as a switch. Circuit Build You can obtain credit towards a pass grade for this unit by successfully completing questions 1 and 2 and completing the report as requested. You can obtain credit towards a merit grade for this unit by successfully completing questions 1, 2 and 3 and completing the report as requested. 1 Zener Diode Circuit Build the circuit below on breadboard. 9V ±r J load voltage Figure 5.1: Voltage regulator circuit A

3 Principles and Applications of Electronic Devices and Circuits Measure the output voltage and record it in the *top row of Table 5.1. Test the load stabilisation of the circuit by replacing the load resistor by one of each value listed in Table 5.1, and record the load voltage for each case. Load Resistance Load Voltage 10 kq * 6,35 1 k Q CZT Q Table 5.1: Load regulation Test the supply stabilisation of the circuit by adding a potentiometer as shown in Figure 5.2. Adjust the potentiometer to give an output as listed in Table 5.2, and record the output voltage in each case. 9V-± 10 kq «" > supply voltage 100 Q 6.2 V 0.5 W 1 kq i j load voltage Figure 5.2: Testing supply regulation Desired Supply voltage Measured 9.0 V -SrlA- 8.5 V Load Voltage 8.0 V t 1 5 6, IS 7.5 V 4,51 L ÿ3 7.0 V E.6S C, 6.5 V 6, 4-4 5, )Q 6.0 V 6, 5,4-6 (jr ÿ 3c-\ 3 2- c Table 5.2: Supply regulation Explain the purpose of the Zener diode A 143

4 BTEC Level 3 Certificate in Electronic Engineering 2 Transistor Circuit Build the circuit below on breadboard and check that the LED is illuminated. 22 kq V BC108 / \ 330 Q I T +9 V emitter base vj/ collector V Figure 5.3: LED circuit Figure 5.4: BC108 transistor (as seen from below) Record the voltages listed in Table 5.3, and use them to calculate the currents. Voltages Currents Supply 3,12-V base base J A LED /, rzi/ collector 0,103V collector Table 5.3: LED voltages and currents Explain the purpose of the LED and the transistor in the circuit. To achieve a merit grade and satisfy assessment criteria M1: You can obtain credit towards a merit for this unit by modifying the circuit. 3 Modify the circuit Modify your circuit so that the LED current is approximately 10 ma, and complete Table 5.4, filling in the voltages measured on your new circuit. Report a b Voltages Currents Supply )MV base o(tz/ base 0,5 twa LED collector TOkI/ collector 1J A Table 5.4: modified circuit Explain how the Zener diode circuit acts as a voltage stabiliser, with reference to your measurements. Explain how the transistor circuit can be used to allow digital logic to operate an LED with reference to the currents flowing in the test circuit(s) A

5 Principles and Applications of Electronic Devices and Circuits ' c Explain the operation of the field-effect transistor in Figure 5.5. Your explanation should refer to voltage levels and currents. +v R, fh /K n V. I R gnd Figure 5.5: FET amplifier circuit Video Record a video of your circuit being built. You must be in the video. Record a video of your circuit in operation and the measurements being taken. You must be in the video. (This question provides evidence for P1, P2 and M1) Task 2 Principles and Applications of Electronic Devices and Circuits: Operational Amplifiers The Assignment Criterion for this task is: P4 Build and test two different types of analogue circuit using operational amplifiers Context The company you work for is planning to develop a new product containing an operational amplifier. In order to assess possible designs, you are required to construct and test two op-amp circuits: an inverting and a non-inverting amplifier. You can obtain credit towards a pass grade for this unit by successfully completing questions 1 and 2 and completing the report as requested A 145

6 BTEC Level 3 Certificate in Electronic Engineering Circuit Build 1 Inverting Amplifier Build the circuit shown in Figure 5.6 on breadboard. 2.2 kq input voltage Output Figure 5.6: Inverting amplifier For each of the voltages in Table 5.5, adjust the potentiometer to give the desired voltage and record the actual input and output voltages. Desired Input voltage Measured Output Voltage 0.0 V 0.5 V 1.0 V 1.5 V 2.0 V 2.5 V 3.0 V 3.5 V 4.0 V 4.5 V 5.0 V Table 5.5: Inverting amplifier Draw a graph of output against input voltage. Estimate the gain from the graph A

7 Principles and Applications of Electronic Devices and Circuits 2 Non-inverting Amplifier This amplifier circuit is intended to produce a large gain. As a result, the input signal would need to be too small for a digital multimeter to read, so a voltage divider is used to attenuate the input by a factor of around 100. Build the circuit shown in Figure 5.7 on breadboard. o [ input input/1000 _o output 100 Q 22 kq 9 V "±" 100 Q 9 v Figure 5.7: Non-inverting amplifier Use an ac source to generate a signal for each of the frequencies in Table 5.6, and measure the input and output voltages. 50 Hz 100 Hz 200 Hz 500 Hz 1 khz 2 khz 5 khz 10 khz Frequency Input Voltage Output Voltage Gain Table 5.6: Non-inverting amplifier Calculate the voltage at the amplifier's non-inverting input, and hence the gain for each data point in the experiment. Draw a graph of gain against input frequency A 147

8 BTEC Level 3 Certificate in Electronic Engineering Report Compare the results of the two experiments to those predicted by theory. Estimate the bandwidth for the second amplifier, describing how you arrived at your value. Your report should include tables of results and graphs, and comment on any discrepancies. Video Record a video of your circuit being built. You must be in the video. Record a video of your circuit in operation and the measurements being taken. You must be in the video. (This question provides evidence for P4) Task 3 Principles and Applications of Electronic Devices and Circuits: Digital Circuits The Assignment Criteria for this task are: P3 P5 Explain the operation of three different logic gates with appropriate gate symbols, truth tables and Boolean expressions Build and test a combinational logic circuit that has three input variables P6 Build and test a sequential circuit using integrated circuit(s) M2 Modify a digital circuit to achieve a given revised specification by selecting and changing up to two logic gates (merit criterion) M3 Evaluate and minimise a three-input combinational logic circuit containing three gates (merit criterion) D2 Compare and contrast two different types of logic family with reference to five characteristics (distinction criterion). Context Your employer is developing safety equipment for an industrial machine. The first part of the circuit displays an alarm if certain conditions are not in place. The second counts the number of times the alarm has been triggered. You are required to build two prototype circuits on breadboard to ensure that they operate as required. Firstly, explain the operation of three different logic gates with appropriate gate symbols, truth tables and Boolean expressions A

9 Principles and Applications of Electronic Devices and Circuits Circuit Build You can obtain credit towards a pass grade for this unit by successfully completing questions 1 and 2 and completing the report as requested. You can obtain credit towards a merit grade for this unit by successfully completing question 1, 2 and 3 and completing the report as requested. 1 Combinational Logic Build the combinational logic circuit shown in Figure 5.8 on a breadboard, taking a note of pin numbers for all the gates used. A B c Figure 5.8: Safety system logic Test the circuit by setting A = 0B=1 C = 0. Record the input(s) and outputs of every gate, as measured by a logic probe. Complete Table 5.7, recording the status of the output for each combination of logic inputs. A B c Desired X Recorded X Table 5.7: Safety system results 40764A 149

10 BTEC Level 3 Certificate in Electronic Engineering 2 Sequential Logic Build the SR latch circuit shown in Figure 5.9 on a breadboard and check that it operates correctly. +5 v 10 KQ 10 KQ "ÿoutput set o\ o reset switch Figure 5.9: Debounced switch Then, build the 3-bit counter circuit shown in Figure on a breadboard, using the output from your latch as a clock input. +5 v clr clr clr _n_ 0. clock from debounced switch Figure 5.10: Counter circuit Test the circuit by using a logic probe to determine the output from each bit of the counter as the clock input is taken high then low. Record the results in the form of a waveform diagram. To achieve a merit grade You can obtain credit towards a merit grade for this unit by successfully redesigning the circuit A

11 Principles and Applications of Electronic Devices and Circuits Redesigning the circuit The new circuit must have the output inverted, as shown in Table 5.8. Also, you are required to use logic minimisation methods to design the simplest possible circuit. Build your new circuit and test it, recording the results in Table 5.8. A B c Desired X Recorded X Report Table 5.8: Redesigned circuit To achieve a pass grade your report should include: Tables of results Circuit diagram for minimised circuit (if attempted) Waveform diagram for counter circuit Show that your circuits are working correctly. To achieve a distinction grade your report should include: Compare and contrast TTL and CMOS logic with reference to characteristics such as Supply voltage Input and output voltages Input and output current Speed Power. Use an inverter ic as an example and quote specific values. You must state the sources of information. (This task provides evidence for D2) 40764A 151

12 BTEC Level 3 Certificate in Electronic Engineering Video Record a video of your circuit being built. You must be in the video. Record a short video of your circuit in operation and the measurements being taken. You must be in the video. (This task provides evidence for P3, P5, P6, M2, M3 and D2) Task 4 Principles and Applications of Electronic Devices and Circuits: Simulation The Assignment Criteria for this task are: P7 Use a computer software package to simulate the construction and testing of an analogue circuit with three different types of components P8 Use a computer software package to simulate the construction and testing of a digital logic circuit with three gates D1 Using a simulation package, analyse the effects of changing the values of circuit parameters on the performance of an analogue circuit containing an operational amplifier or transistors (distinction criterion) Context You are required to simulate two circuits using a computer package, one analogue and one digital. The analogue circuit will be a simple active filter, while the digital circuit will be a combinational logic circuit. You can obtain credit towards a pass grade for this unit by successfully completing question 1.1 and 2 and completing the report as requested. You can obtain credit towards a merit grade for this unit by successfully completing questions 1.1, 1.2 and 2 and completing the report as requested. 1.1 Analogue Simulation A low-pass filter circuit is required for use with a sound recording device your employer is developing. Simulate using a relevant simulation software package (such as LTSpice available at: the filter design in Figure A

13 Principles and Applications of Electronic Devices and Circuits 22.5 nf input 1 KQ 1 Kq 0 output 11.3 nf=ÿz Figure 5.11: Low-pass filter Produce a graph of output voltage against frequency in the range 1 khz to 1 MHz. and print it out. To achieve a distinction grade: 1.2 You can obtain credit towards a distinction for this unit by successfully answering the question below. Produce two more graphs, replacing the 11 nf capacitor with: a 47 nf b 0.47 nf Analyse (i.e. examine in detail in order to explain) the effect of replacing the 11 nf capacitor. 2 Digital Simulation Simulate using a relevant simulation software package (such as LTSpice available at: the digital circuit design in Figure This circuit is required for an alarm to be fitted to a car. A warning chime is to sound whenever the driver opens the door with the lights on but the ignition off. door open Q- ignition on q- chime lights on q. Figure 5.12: Car light warning system Test the circuit by running through all eight possible combinations of input and recording the output in Table A 153

14 BTEC Level 3 Certificate in Electronic Engineering Door Open Ignition On Lights On Chime Table 5.9: Car light warning system Then, record the input and output waveforms while simulating the following driver actions: Ignition turned on Lights turned on Ignition turned off Door opened Door shut Lights turned on Door opened. Print out the waveforms, ensuring that all of the test data is visible. Report Your report should include: Printouts of both circuits The graph of gain against frequency for the filter An estimate of the gain and bandwidth of the filter, along with an explanation of how you arrived at these figures Completed truth table for the car warning system A waveform diagram along with a description indicating what the driver is doing and showing that the chime is operating correctly. To achieve a pass with distinction, your report should also analyse the effects of changing component values on the performance of the filter circuit. (This task provides evidence for P7, P8 and D1) A

15 Principles and Applications of Electronic Devices and Circuits In this assessment you will have opportunities to provide evidence against the following assessment and grading criteria: To achieve a pass grade the evidence must show that the learner is able to: PI Explain the purpose of two different types of diode, each in a different electronic circuit application P2 Explain the operation of two different types of transistor, one in an analogue and one in a digital circuit P3 Explain the operation of three different logic gates with appropriate gate symbols, truth tables and Boolean expressions P4 Build and test two different types of analogue circuit using operational amplifiers To achieve a merit grade the evidence must show that, in addition to the pass criteria, the learner is able to: M1 Modify an existing analogue circuit to achieve a given revised specification by selecting and changing the value of one of the components M2 Modify a digital circuit to achieve a given revised specification by selecting and changing up to two logic gates M3 Evaluate and minimise a three-input combinational logic circuit containing three gates To achieve a distinction grade the evidence must show that, in addition to the pass and merit criteria, the learner is able to: D1 Using a simulation package, analyse the effects of changing the values of circuit parameters on the performance of an analogue circuit containing an operational amplifier or transistors D2 Compare and contrast two different types of logic family with reference to five characteristics r P5 Build and test a combinational logic circuit that has three input variables P6 Build and test a sequential circuit using integrated circuit(s) P7 Use a computer software package to simulate the construction and testing of an analogue circuit with three different types of components P8 Use a computer software package to simulate the construction and testing of a digital logic circuit with three gates Now send your answers to ICS A 155

16 BTEC Level 3 Certificate in Electronic Engineering A