It produces a 1 output only when its two inputs are equal i. Load circuit for 3 state and open drain outputs s1 vcc rl 1 kw gnd from output under test l see note a test point load circuit for totem pole outputs open 50% vcc 50% vcc cc 50% vcc 50% vcc 50% vcc cc cc voh 0. How a logic circuit implemented with aoi logic gates could be reimplemented using only nor gates that using a single gate type, in this case nor, will reduce the number of integrated circuits ic required to. This in turns brings the overall wl ratio of the conventional nand gate at the load equal to the wl ratio of the proposed nand gate. Digital logic or gate digital gates electrical technology. This circuit is similar to an or gate circuit, except that the output is connected to the collector of both transistors and the emitter of each transistor is connected to ground. A logic family is a complete set of logic gates that are manufactured using a particular type of electronic circuitry. You can build a twotransistor nor gate by following the steps outlined in this project. Similarly, any 2level implementation of a productofsums pos expression can be converted to an allnor gate implementation of the circuit. So if any one or both inputs are high,the output of nor gate will. Npn transistor nor gate circuit sully station technologies. The diagrams below show two ways that the nand logic gate can be configured to produce a not gate. A universal gate is a gate which can implement any boolean function without need to use any other gate type.
Project on logic gates in physics pdf a logic gate is an idealized or physical device implementing a boolean function, that is. Here, we have shown how to construct the basic logic gates not, and, or gates using nor gate which is one of the universal gates. Instructor demonstrates an electric circuit that produces an am radio. How an nor gate can be using to replace an and gate, an or gate or an inverter gate. Introduction to logic gates not, and, nand, or, nor. Pressing either one of the switches causes that switchs input. Nor is the result of the negation of the or operator. This is a notand gate which is equal to an and gate followed by a not gate.
It can also be done using nor logic gates in the same way. Logic gates class 12 physics investigatory project report. Nor gate is the combination of not gate and or gate. From the logic circuit of the nor gate, the output can be expressed by the equation shown below.
Normally invertors connected directly to input variables are not counted as a level in a circuit terminology 1. I have attached the complete project report for your reference and you can download it for free here. How a logic circuit implemented with aoi logic gates could be reimplemented using only nor gates that using a single gate. This gate is mainly used in applications where there is a need for mathematical calculations.
The truth table, logic symbol and transistor circuit diagrams of nand gate are shown below. Sep 12, 2015 the output of a nor gate circuit should be high only if both the gate inputs are low. So when the button is pressed the corresponding pin of gate goes high. I have created a truth table next the diagram based on my understanding of basic mosfet switching. Jun 19, 2019 it becomes high for any other combination of inputs. How the logic circuits can be designed using these gates. For any other combination of inputs, the output is logic 0 level.
The inputs to the nor gate are two manual push button switches each of which drives a transistor. Drive a power mosfet with a gate driver or logic level mosfet. And then the inputs are connected to power through a button. The nor gate is a digital logic gate that implements logical nor it behaves according to the truth table to the right. What is logic gate and, or, xor, not, nand, nor and xnor. Nor gate is the logic gate and is one of the universal gates. The output of notgate should be low when the input is high. Aim to study about logic gates introduction logic gates.
The output of an or gate assumes 0, if both inputs assumes 0. Digital electronicslogic gates basics,tutorial,circuit. Two level nor gate implementation all about circuits. Nor gate is used to construct the basic gates similar to and gate. Xor gate assumes logic 1 state when any of its two inputs assumes a logic 1 state. This circuit is nearly identical to the transistor or gate. Elec 2210 experiment 1 basic digital logic circuits. Generally, nor gate have 2 inputs, lets say x and y, and one output z. When both the inputs assume the logic 0 state or when both the inputs assume the logic 1 state, the output assumes a logic. Doc physics project theory logic gates class 12 cbse. Nov, 2011 circuitlab provides online, inbrowser tools for schematic capture and circuit simulation. It can also in some senses be seen as the inverse of an and gate. The truth table and the graphic symbol of nor gate is shown in the. However, by designing the circuit such that the output is taken at a voltage divider between the transistor and the positive voltage, the nor circuit has an inverting component.
This book is writ ten for all the people who love innovation. When two nor gates are crossconnected as shown in the schematic diagram, there will be positive. It can also be implemented using andnor circuit as it is equivalent to nand. Describe and, or or nand, nor logic gates realize logic gates belonging to different logic families such as dtl, ttl and cmos understand the factors that define the performance of a logic gate. Such a circuit is easy to build, using a single transistor and a pair of resistors. The truth table and equivalent gate circuit an invertedoutput nor gate are shown here. Iec 61712 and its successor iec 606172 do not include the distinctive shape symbols. Jul 09, 2015 nor gate is the logic gate and is one of the universal gates. Most logic gates have two inputs and one output and are based on boolean algebra.
Of course, totempole output stages are also possible in both nor and or ttl logic circuits. If all inputs are low or 0, the output will be off. In this project, we will show how to build an or gate circuit with diodes. Universal gate nor universal gate nor this presentation will demonstrate the basic function of the nor gate. The outputs of all nand gates are high if any of the inputs are low. In this new coding we made the output of the conventional nand gate coincide with the proposed nand gate. An or gate may be created by adding an inverter stage to the output of the nor gate circuit. So with two buttons we can realize the truth table of nand gate.
Basic logic gates and, or, and not gates objectives. Logic gates are primarily implemented electronically using diodes or. In this not gate circuit we are going to pull down both input of a. If we connect the output y of or gate to the input of a not gate, then the gate obtained is the nor gate. So the not gate provides output which is inverted logic of input.
The input is connected through resistor r2 to the transistors base. The output y is voltage at c with respect to earth. This is why, a not gate sometimes is referred as an inverter not to be confused with a power inverter. Universal gate nor now i will demonstrate the basic function of the nor gate.
A logic gate is a building block of a digital circuit. This was achieved by changing the w for nmoss in conventional nand gate from 50 to 100. Logic gates not, or, and, nor, nand, xor, xnor gate, pdf. As of circuit diagram an inverter gate has one output for one input. These tools allow students, hobbyists, and professional engineers to design and analyze analog and digital systems before ever building a prototype. Logic gates and, or, not, nor, nand, xor, xnor gates. By combining not gate and or gate, nor gate can be constructed. A not gate is a logical gate which only inverts the input digital signal. The graphic symbol for the nor gate consists of an or symbol with a bubble on the output, denoting that a complement operation is performed on the output of the or gate. As by the truth table, the output of not gate will be high when the input is low. Key topics presented in logic gates class 12 physics investigatory. The gate is either a nand or an ex or gate b nor or an exnor gate. Ttl nor and or gates logic gates electronics textbook. Schematic diagram illustration instructions the 4001 integrated circuit is a cmos quad nor gate, identical in input, output, and power supply pin assignments to the 4011 quad nand gate.
A logic gate is an idealized or physical device implementing a boolean. An xor gate is a two input, one output logic circuit. A high output 1 results if both the inputs to the gate are low 0. Several kinds of digital logic circuits are the basic elements that form the building blocks for such complex digital system as the.
Depending on the type of logic gate being used and the. The output of an or gate assumes 1, if one or more inputs assumes 1. Logic gates class 12 physics investigatory project. When power is applied to this circuit, both inputs initially will be low, and the output will be high. Thus operation of or gate is based on the following rules. Oct 02, 2017 calculating gate resistor for logic level mosfet. Click on the inputs on the bottom to toggle their state. An or gate is a logic circuit that turns on an output if one of the inputs is high or a logic state of 1. The output of a logic gate is 1 when all its input are at logic 0. If any 1 of the inputs are high, the output will turn on. So in calculators, computers and many digital applications use this gate. Logic gates practice problems key points and summary first set of problems from q. This circuit produces a sound similar to the police siren.
The nor gate represents the complement of the or operation. Aim to study about logic gates introduction logic gates are. Jul 26, 2017 in this physics video lecture in hindi for class 12 we explained the working of various logic gates like or, and, not, nor, nand, xor and xnor gate and also drawn their truth tables. As a nor gate is equivalent to an or gate leading to not gate, this automatically sees to the or part of the nor gate, eliminating it from consideration and leaving only the not part. Converting logic level sink to source for powering nchannel mosfet gate. If the input is high, the output is low, and if the input is low, the output is high. If at least one of the inputs is high, the output is low. Since the logic circuit involves an or gate followed by an inverter, the output can only be high when both the inputs are low. The output of a nor gate circuit should be high only if both the gate inputs are low. An encircled plus sign is used to show the eor operation. Logic gate actually the term logic is applied to digital circuits used to implement logic functions.
Friends, heres a great physics investigatory project for class 12 students. In order to turn this nor gate circuit into an or gate, we would have to invert the output logic level with another transistor stage, just like we did with the nandtoand gate example. In this physics video lecture in hindi for class 12 we explained the working of various logic gates like or, and, not, nor, nand, xor. In this nand gate circuit diagram we are going to pull down both input of a gate to ground through a 1k. In practice, this is advantageous since nand and nor gates are economical and. Not gate is a digital logic gate, designed for arithmetic and logical operations, every electronic student must have studied this gate is hisher career. It produces a 1 output only when even number of 1 is present at the input. The following inference can be easily drawn from the workingof electrical circuit. May 24, 2014 logic gates and, or, not, nor, nand, xor, xnor gates.
It becomes high for any other combination of inputs. The nor gate has two inputs x and y, and a single output z. The action of logic circuits is usually summarized in the form of truth tables, which shows the output for the combinations of the input signals. At any given moment, every terminal is in one of the two binary conditions false high or true low. How a logic circuit implemented with aoi logic gates could be reimplemented using only nor gates that using a single gate type, in this case nor, will reduce the.
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