International Journal of Science, Engineering and Technology Research (IJSETR) Volume 1, Issue 1, July 2012 Development of Digital Logic Trainer for Student’s Experimentation Myo Su Su Theint1, Zaw Myo Tun2 Abstract– This research work describes design, development and application of a digital trainer circuit prototyping system, for student in their digital electronic course. The primary objective is to design an inexpensive, simple to use device that could be retained by students, so that they could undertake digital experimentations. This research paper is one part of the Digital Trainer Board which contains power supply section, logic gate section, function generator section and encoder/decoder section. It mainly concerns with logic gate section. Logic gate section is aimed to perform basic Boolean functions, such as AND, OR, NOT, NOR, NAND and so on. All logic gate circuits are firstly simulated in Multisim simulation environment and then constructed. After construction, several tests have been performed and satisfactory results are obtained Index Terms— Digital logic trainer, AND gate, NAND gate, NOR gate, OR gate, NOT gate. I. INTRODUCTION Digital electronics is now used in all fields of electronics from computers to digital phones and most industrial machines and motor vehicles. When prototyping digital electronic circuits, specific digital input signals are required to design the digital circuit. To accomplish this task, a teaching device known as a “Digital Trainer” is utilized. The purpose of this research work is to provide a method for students to test digital circuits, with a simple and inexpensive digital trainer. Digital trainer kit is a self contained set of electronic circuits that can be interlinked by students to create working circuits. Component parts cannot be removed or lost in the classroom and interlinking is performed by short coloured cables fitted with small insulated alligator clips. Rapid changes in the field of engineering technology have increased the need for universities to provide engineering and engineering technological students with meaningful and relevant practical experiences. To partial fulfill this need, study and implementation of digital logic trainer board has been done. The digital logic section contains NOT gate, AND gate, OR gate, NAND gate and NOR gate with control switches and LEDs. The overall block diagram of the system is shown in figure 1. NOR Gate Section OR Gate Section AND Gate Section NAND Gate Section NOT Gate Section Test Bench Bread Board Input Switches 1-32 Display LED 1-32 Fig. 1. Overall Block Diagram Digital logic Trainer II. HARDWARE DESIGN The logic gate section contains AND gate subsection, NAND gate subsection, OR gate subsection, NOR gate subsection and NOT gate subsection. A. AND Gate Section AND gate subsection has been implemented with 74HC08 AND gate IC. This IC contains four AND gates. First of all, the AND gate test circuit is constructed. This circuit is very simple and shown in figure 2 Eight switches are used to give inputs for four AND gates and four LEDs are used to check the outputs. 5 volts 1 2 3 4 14 7408 Quad AND Gate 13 12 11 5 10 6 9 7 8 Fig. 2. AND Gate Test Circuit B .NAND Gate Section NAND gate subsection has been implemented with 74HC00 NAND gate IC. This IC contains four NAND gates. NAND gate test circuit is constructed as shown in figure 3. Eight switches are used to give inputs for four NAND gates and four LEDs are used to check the outputs. 5 volts 1 14 2 13 3 4 Manuscript received Oct 15, 2011. Myo Su Su Theint, Electronic Department, Mandalay Technological University., (myonyein87@gamil.com). Mandalay, Myanmar, 09-401646916 Zaw Myo Tun, Electronic Department, Mandalay Technological University.,, Mandalay, Myanmar, 09-444045182, (zawmyotun.mtu@ gmail.com). 5 6 7 12 7400 Quad NAND Gate 11 10 9 8 Fig.3.NAND Gate Test Circuit 1 All Rights Reserved © 2012 IJSETR International Journal of Science, Engineering and Technology Research (IJSETR) Volume 1, Issue 1, July 2012 C.OR Gate Section OR gate subsection has been implemented with 74HC32 OR gate IC. This IC contains four OR gates. OR gate test circuit is constructed as shown in figure 4. Eight switches are used to give inputs for four OR gates and four LEDs are used to check the outputs. 5 volts 1 14 2 13 3 4 5 6 NOT gate. The circuits for logic gates are simulated separately. Figure 7 shows the simulation window for AND gate logic circuit. Two switches are used as input signals for the gate and output is tested with Light Emitting Diode (LED). The trainer uses 7408 Quad AND gate and the results assure the AND logic. 12 7432 Quad OR Gate 11 10 9 7 8 Fig .4. OR Gate Test Circuit D.NOR Gate Section NOR gate subsection has been implemented with 74HC02 NOR gate IC. This IC contains four NOR gates. NOR gate test circuit is constructed as shown in figure 6. Eight switches are used to give inputs for four NOR gates and four LEDs are used to check the outputs. 5 volts 1 13 3 5 6 Figure 8 shows the simulation window for OR gate logic circuit. Two switches are used as input signals for the gate and output is tested with Light Emitting Diode (LED). The trainer uses 7432 Quad OR gate and the results assure the OR logic. 14 2 4 Fig .7. Simulation Window for AND Gate Logic Test Circuit 12 7402 Quad NOR Gate 7 11 10 9 8 Fig .5. NOR Gate Circuit Test E.NOT Gate Section NOT gate subsection has been implemented with 74HC02 NOT gate IC. This IC contains six NOT gates. NOT gate test circuit is constructed as shown in figure 6. Six switches are used to give inputs for six NOR gates and six LEDs are used to check the outputs. 5 volts 1 16 2 3 4 5 15 7404 NOT Gate Fig. 8. Simulation Window for AND Gate Logic Test Circuit Figure 9 shows the simulation window for NAND gate logic circuit. Two switches are used as input signals for the gate and output is tested with Light Emitting Diode (LED). The trainer uses 7400 Quad NAND gate and the results assure the NAND logic. 14 13 12 6 11 7 10 8 9 Fig.6.NOT Gate Circuit Test III. SIMULATION The simulation of logic gate section has been done with Multisim Simulation Software. The logic gates used in the trainer are AND Gate, NAND Gate, OR gate, NOR gate and Figure.9. Simulation Window for NAND Gate Logic Test Circuit 2 All Rights Reserved © 2012 IJSETR International Journal of Science, Engineering and Technology Research (IJSETR) Volume 1, Issue 1, July 2012 Figure 10 shows the simulation window for NOR gate logic circuit. Two switches are used as input signals for the gate and output is tested with Light Emitting Diode (LED). The trainer uses 7402 Quad NOR gate and the results assure the NOR logic. (a) (b) Fig .10. Simulation Window for NOR Gate Logic Test Circuit Figure 11 shows the simulation window for NOT gate logic circuit. One only switch is required as input signal for the gate and output is tested with Light Emitting Diode (LED). The trainer uses 7404 NOT gate IC and it contains six NOT gates. (c) (d) Fig.12. Results with AND gate with various inputs; (a) inputs (1,1), (b) inputs (1,0), (c)inputs (0,0), (d)inputs (0,1) Table .1 .Truth Table for AND gate Fig .11. Simulation Window for NOT Gate Logic Test Circuit . Test and results of OR gate implementation is shown in figure 1to 4. The results satisfy that truth table for OR gate shown in table 2. IV. TEST AND RESULTS OF DEVELOPED TRAINER BOARD Test and results of AND gate implementation is shown in figure 1to 4. The results satisfy that truth table for AND gate shown in table 1. 3 All Rights Reserved © 2012 IJSETR International Journal of Science, Engineering and Technology Research (IJSETR) Volume 1, Issue 1, July 2012 (a) Fig .14. Results with NOR gate with various inputs; (a) inputs (1,1), (b) inputs (1,0), (c)inputs (0,0), (d)inputs (0,1) Table .3. Truth Table for NOR gate (c) (d) Fig .13. Results with OR gate with various inputs; (a) inputs (0,0), (b) inputs (0,1), (c)inputs (1,0), (d)inputs (1,1) Table .2. Truth Table for OR gate Test and results of NAND gate implementation is shown in figure 1to 4. The results satisfy that truth table for NAND gate shown in table 4. (a) (b) Test and results of NOR gate implementation is shown in figure 1to 4. The results satisfy that truth table for NOR gate shown in table 3. (c) (d) Fig.15. Results with NAND gate with various inputs; (a) inputs (0,1), (b) inputs (1,0), (c)inputs (0,0), (d)inputs (1,1) Table. 4 .Truth Table for NAND gate (a) (b) A 0 0 1 1 B 0 1 0 1 Output 1 1 1 0 Test and results of NOT gate implementation is shown in figure 1to 4. The results satisfy that truth table for NOT gate shown in table 5. (c) (d) 4 All Rights Reserved © 2012 IJSETR International Journal of Science, Engineering and Technology Research (IJSETR) Volume 1, Issue 1, July 2012 [2] [3] [4] [5] [6] (a) Bio-technology, Mohai, India, Microcontroller Based Home Automation System with Security” Umm Al-Qura University,Computer Engineering Department, “ Digital Design Lab Manual [http://www.elenco.com/digital/analog trainer/XK 550 EcE-2022 Digital Electronics, Department of Electronic Engineering Department of Technological and Vocational Education, Ministry of Science and Technology, Myanmar. www.ALLDATASHEET.com 1972 EXAR Corporation, Datasheet June 1997 (b) Fig .16 .Results with NOT gate with various inputs; (a) inputs (0), (b) inputs (1), Table .5. Truth Table for NOR gate Fig .17. Complete Circuit Diagram of Digital Logic Gate Section V .SUMMARY The hardware design and software implementation of the digital logic trainer is described. The simulation results of logic gate section has been done in Multisim. Thirty-two switches labeled SW1 to SW32 are applied as an input in this system. VI. CONCLUSION The development of digital logic trainer for students’ experimentation is described. The components required in trainer board are chosen. The overall circuit for logic trainer is designed The complete system can be implemented to perform higher standard than any other commercial products. An inexpensive and excellent digital trainer board is designed and implemented. Multisim software is used for simulation. The results are convenient and simple for students to test. REFERENCES [1] Inderpreet Kaur (Asstt.Prof), Rayat and Bahra Institute of Engineering and 5 All Rights Reserved © 2012 IJSETR