BUILD BASIC GATES USING UNIVERSAL GATES (NAND GATE) Digital Techniques PREPARED BY:
1440 AKASH SINGH 1441 ASHWINI BANSODE 1442 JINENDRA BAFNA 1443 KARAN BHANDARE GUIDE BY:
Ms. C. M. Maind
AISSMS’s POLYTECHNIC PUNE 411001 OCTOBER …., 2018
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Abstract
the implementation of universal gates in logic circuits has b een made. There are two functions required to observe and F1 is in the SOP form while F2 is in the POS form. We have been given four variables (A, B, C and D) or in other words, four inputs that we must carry out in their 16 possible combinations by connecting toggle switches for each and one toggle switch that was always on to represent each of combination output. We began to construct a circuit diagram composed mainly of the AND, OR and an INVERTER logic gate for each of the two functions and listed every output voltages we measured from the VOM. We also constructed co nstructed a series of possible answer for each combination so as to serve as a guide to the values were going to measure. We then compared our computed or expected value to what we measured in actual operation and the results did match to one another .Then, to perform the main point of the experiment which was the universal gates, we are required to reconstruct the circuits in the first procedure using universal gates only, but must maintain the same behaviour the previous circuits had obtained. In other words, we have to prove why the NAND and NOR gates are so called universal gates
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Table of Contents
CONTENTS
PAGE NO
1. INTRODUCTION
4
2. MATERIALS
6
3. DATA / RESULT
7
4. PRACTICAL APPLICATION
9
5. CONCLUSION
12
6. ACKNOWLEDGEMENT
13
7. BIBLIOGRAPHY
14
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INTRODUCTION A universal logic gate is is a logic gate that can be used to construct all other logic logic gates. There are many articles about how NAND and NOR are universal gates, but many of these articles omit other gates that are also universal gates. This article covers two input logic gates, demonstrates that the NAND gate is a universal gate, and demonstrates how other gates are universal gates thatcan be used to construct any logic gate
NAND GATE
the NAND the NAND function has functional completeness all logic systems can be converted into NAND gates – gates – the the mathematical mathemat ical proof for this was published by Henry M. Sheffer in Sheffer in 1913 in the Transactions of the American Mathematical Society Society (Sheffer 1913). This is also true for NOR gates. gates. In principle, any combinatorial logic function can be realized with enough NAND gates
Q = A NAND B
Truth Table Input A Input B
Output Q
0
0
1
0
1
1
1
0
1
1
1
0
NOR GATE
A NOR gate is a logic gate which gives a positive output only when both inputs are negative. Like NAND gates, gates, NOR gates are so-called so -called "universal "universal gates" that can be combined to form any other kind of logic of logic gate. gate . For example, the first embedded system, system, Apollo Guidance Computer , was built exclusively from NOR gates, about 5,600 in total total for the later versions. versions. Today, integrated circuits are not constructed exclusively from a single type of gate. Instead, EDA tools are used to convert the description of a logical circuit to a netlist of complex gates (standard cells) cells ) or transistors
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Q = A NOR B
Truth Table Input A Input B
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Output Q
0
0
1
0
1
0
1
0
0
1
1
0
MATERIALS
IC 7400 (3)
Zero PCB
7 connecters
DC Power Supply
Connecting wires
Led (3)
14 Pin IC base
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DATA AND RESULT A NAND gate is a universal gate, meaning that any other gate can be represented as a combination of NAND gates. NOT
A NOT gate is made by b y joining the inputs of a NAND gate together. to gether. Since a NAND gate is equivalent to an AND gate followed by a NOT gate, joining the inputs of a NAND gate leaves only the NOT gate. Desired NOT Gate
NAND Construction
Q = NOT( A )
= A NAND A
Truth Table Input A
Output Q
0
1
1
0
AND
An AND gate is made by inverting the output of a NAND gate as shown below. Desired AND Gate
NAND Construction
Q = A AND B
= ( A NAND B ) NAND ( A NAND B ) Truth Table
Input A Input B
Output Q
0
0
0
0
1
0
1
0
0
1
1
1
If the truth table for a NAND gate is examined or by applying De Morgan's Laws, Laws, it can be seen that if any of the inputs are 0, then the output will be 1. To be an OR gate, however, the output
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must be 1 if any input is 1. Therefore, if the inputs are inverted, an y high input will trigger a high output. Desired OR Gate
NAND Construction
Q = A OR B
= ( A NAND A ) NAND ( B NAND B ) Truth Table
Input A Input B
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Output Q
0
0
0
0
1
1
1
0
1
1
1
1
PRACTICAL APPLICATION
(a) Burglar alarm When the switch is closed one input of the NAND gate is LOW. When the LDR is in the light the other input is LOW. This means that if either of these things happen, i.e. the switch is closed or the light is on one of the inputs is LOW, the output is HIGH and the buzzer sounds.
(b) Freezer warning buzzer When the thermistor is COLD its resistance is LARGE and the input to the NAND gate is high. Since the NAND gate is connected as an INVERTER the output is LOW. As the thermistor warms up its resistance decreases, the voltage across it falls and the input to the NAND gate falls. When it becomes low enough the output becomes HIGH and the buzzer sounds. How would you adjust the temperature at which the buzzer came on?
Further circuits using logic gates The following four circuits demonstrate some further practical applications of logic gates, the function of each circuit being explained. A push-button lock To open the lock the solenoid must be activated and this can be done by pressing both switches A and B. If B is pressed before A, however, the buzzer will sound.
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A light-activated burglar alarm When the switch is in position A the buzzer stays off whatever the illumination of the light-dependent resistor. If the switch is closed in position B the buzzer will come on, however, and stay on when a brief flash of light (perhaps from the torch of a burglar) falls on the light- dependent resistor. The buzzer may only be turned off by returning the switch to position A.
A safety thermostat The two contacts X and Y are near the top of the hot water tank and are normally covered with water so that there is a contact between them. The thermistor is also in the water. If the water is too cold and if the contacts are also covered the heater comes on. The temperature at which this occurs may be set by the variable resistor R.
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An automatic watering system This is designed to water plants only if the contacts, which may be buried in the soil, are too dry and it is night-time. The relay closes and starts the pump only if both these conditions are fulfilled. (Presumably somebody waters the plants in the daytime because if the switch is pressed the water pump works regard less.)
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CONCLUSION
In conclusion, a NAND gate is an inverted AND gate, and a NOR gate is an inverted OR gate. The output of a two input NOR gate is low, when either one or both inputs are “High”. In Comparison, Comparison, The output of o f a two input NAND gate is high, when either one or both inputs are “LOW”. To configure a NAND or NOR gate to function like an inverter, connect the inputs together.
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BIBLIOGRAPHY https://www.google.co.in/url?rc https://www.goo gle.co.in/url?rct=j&q=wp3E t=j&q=wp3EDU DU https://www.google.co.in/url?rct=HJU=HTMLBEGINNERS https://writinginstructor. https://writ inginstructor.org/files/co org/files/conciusion.htm nciusion.htmll https://www.Decoder.com https://www.chrome.com https://informatiabout7segmentdecoder https://www.google.com
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ACKOWLEDGEMENT In performing our assignment, we had to take the help and guideline of some respected persons, who deserve our greatest gratitude. The completion of this assignment, give us much pleasure. We would like to show our gratitude to Mrs.C.M.Maind for give us a god guideline for assignment throughout numerous consultations we would also licke to expand our deepest gratitude to all those who have directly and guided us in writing this assignment. In addition, a thank you to professor of work shop mam who introduced us to the methodology of work, and whose passion for the ‘’underlying structures’’ had lasting effect. We also thank the University of AISSMS for consent to include cop yrighted pictures as a part of our paper. Man y people, especially our classmates and team members itself, have made v aluable comment suggestion on this proposal which gave us an inspiration to improve our assignment. We thank all the people for their help directly and indirectly our assignment.
Guided By- Mrs.C.M.Maind
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