A PRESENTATION ON
“PRACTICAL USES OF LOGIC GATES”
By : Abiral Gautam

LOGIC GATES
• The logic gates are the devices that performs basic logical functions that are
fundamental to digital circuits.
• It performs a logical operation on one or more binary inputs and produces a
single binary output.

TYPES OF LOGIC GATES
• There are 7 types of logic gates.
• Out of 7 types of logic gates, 3 are basic logic gates (AND,OR,NOT) and 4 of
them are derived logic gates (NAND, NOR, X-OR, X-NOR).
• Derived logic gates are the gates that are derived from the basic logic gates.

TYPES OF LOGIC GATES

WHAT DOES LOGIC GATES LOOK LIKE ?

HOW LOGIC GATES ARE MADE ?
• Made using digital circuits and components like Transistor, Resistor and Diodes.
• Specific implementation depends on the type of gate and technology used.
Transistor Resistor Diode

WHAT ARE THE USES OF LOGIC GATES?

AND GATE
• AND Gate performs logical AND operation.
• The output of AND gate isTrue only when its all input are true. If one input is
False then the output is also False.
• Boolean Expression :Y = A.B where A and B are inputs andY is output
• Mostly used in digital data transmission for either allowing or disallowing the
data through a channel
• Used in alarm circuits, automatic temperature-regulating circuits, etc.

AND GATE USE IN BURGLAR ALARM
Motion Sensor
Alarm Switch
AND GATE Burglar Alarm
On/Off
On/Off
If the alarm switch is ‘ON’ and if a burglar enters into the room, then he/she will set the
motion sensor switch “ON”, the alarm is activated.

OR GATE
• OR Gate performs logical OR operation.
• The output of OR gate isTrue if atleast one input isTrue
• Boolean Expression :Y = A + B where A and B are inputs andY is output
• If occurrence of one or more than one event is to be detected and action is to
be taken then OR gate can be used.

OR GATE USE IN DORBELL SYSTEM
Front Door Switch
Back Door Switch
Doorbell
If either the front door switch or the back door switch is pressed, the doorbell rings.
OR GATE

NOT GATE
• NOT Gate performs logical NOT operation.
• The output of NOT gate isTrue if the input is false and vice-versa
• Boolean Expression :Y = A’ where A is input andY is output
• NOT gate is mostly used in temperature control systems.

NOT GATE USE IN TEMPERATURE CONTROL SYSTEMS
Temperature Sensor
(Above 20 ℃ ) Heating System
If the temperature is above 20 ℃ then the heating system turns off .
If the temperature is below 20 ℃ then the heating system turns on.
NOT GATE
On/Off

NAND GATE
• NAND Gate is the combination of NOT gate and AND gate.
• The output of NAND gate is False if only all input isTrue.
• Boolean Expression :Y = (A.B)’ where A and B are input andY is output
• NAND gate are used in Failure Detection System, Freezer warning buzzer, etc.

NAND GATE USE IN FAILURE DETECTION SYSTEM
Alarm
While all the devices are working the input to the NAND Gate are 111 so the output is 0.
But if a device stops working then the output of NAND gate will become 1 and the alarm
will ring.
Device 1 Device 2 Device 3

NOR GATE
• NOR Gate is the combination of NOT gate and OR gate.
• The output of NOR gate isTrue if only all input are False else the output will
be False.
• Boolean Expression :Y = (A + B)’ where A and B are input andY is output
• NOR gate are used mostly in Mixer Tanks in Industries.

NOR GATE USE IN MIXER TANK
Ingridient 2
Ingridient 1
Motor
Mixer tank
When the both ingridients are filled up in the tank the input will be 0 and the NOR gate will give
output 1 and the motor of the mixer starts

X-OR GATE (EXCLUSIVE OR)
• X-OR gate is a digital logic gate that gives true output if the number of true
inputs are odd else it will give false output.
• Boolean Expression :Y = A’ . B + A . B’ where A and B are input andY is output
• X-OR gate can be used in the conveyer belts in industries.

X-OR GATE USE IN CONVEYER BELT
Box Box Box Box
Conveyor Belt
Controller
Color Sensor
Motor
In the conveyer belt above, when the orange boxes are detected by the color sensor then the both inputs
will be 1 but when a black box arrives the color sensor input will change to 0 which makes the output of
X-OR gate 1 and the motor will activate and the black box will be kicked out.
Orange color is set true

X-NOR GATE (EXCLUSIVE NOR)
• X-NOR gate is a digital logic gate that gives output the complement of output
of X-OR gate
• Boolean Expression :Y = A . B + A’ . B’ where A and B are input andY is output
• X-NOR gate are used mainly in Parity Checkers, Computers, Mobile Phones,
and are used for error detection in data transmission systems like Anti-Lock
Braking System, Engine Control Unit, Heart Monitors, ECG, etc.

X-NOR GATE USE IN PARITY CHECKER CIRCUIT
A
B
C
P
Cp
A B C P Cp
0 0 0 0 1
0 0 0 1 0
0 0 1 0 0
0 0 1 1 1
0 1 0 0 0
0 1 0 1 1
0 1 1 0 1
0 1 1 1 0
ODD PARITY CHECKER
If the 4-bit received message contains even number of 1 then the value of Parity Checker (Cp) is 1 which means
error and the data is invalid and If the 4-bit message contains odd number of 1 then the value of Cp is 0 which
means no error.

THANK YOU