1. Logic Gates

2. Learning outcomes: At the end of the lesson you should be able to:
Identify gates symbols (NOT , AND, OR)
Draw truth table for each of the above types of gate

3. Definition
Logic gates are the building blocks of digital circuits. 

4. Gate
A gate has two states either open or close
open
closed

5. Similarly 1 or 0 Logic gates process signals in only 2 state Either
ON or OFF
True or False

6. Logic Gates Each gate has 1 or more inputs and produces 1 output
If the number of input(s) is X then the number of possible outcomes are 2x
E.g. if number of input = 1 then the number of possible output will be 21 =2

7. NOT Gate
NOT

8. NOT Gate The NOT gate is also known as an inverter
The output of a NOT gate is the inverse of its input
If A is the input then the output will be (NOT A) A A A

9. Truth Table of NOT Gate
INPUT (A)
OUTPUT () 1

10. AND Gate
AND

11. AND Gate
The output of an AND gate is True only if all inputs are True, otherwise the output is false A B Q 1 A B Q
Q = A.B

12. OR Gate
The output from an OR gate is True if any input is True, otherwise the output is false A B Q