**Logic Operators, Truth Tables and Logic Gates**

Starter Activity

Jig Saw Puzzle

Learning objectives

All must be able to name the three basic logic gates

Some should be able to use the truth table to work out the output of possible combinations

Some could discuss a statement which negates an output value.

Call register

What are logic gates

What is a Truth Table

Why are Truth tables used

Answers

A truth table shows how a logic circuit's output responds to various combination of the input

A logic gate is the basic block of digital circuits. It determines how data is converted inside the computer

Statements

A statement is a sentence which has a declarative

meaning. That means th

e

statement can only be

either

true or false

Give examples of statements

Indigo is a colour in the rainbow

Fish can swim

Cars have wheels

The

three basic

logic gates operators

What is a statement

Research Questions

To help with calculations.

To help plan the layout of a special type of electrical circuitry/digital circuits.

To minimise cost.

To test statements

Truth table

(logic use letters to represent statements

in this case we are using P & Q)

Unique possible combinations (on or off, 0s and 1s)

"AND" -

P

Q

P Q

T

T

T

T

F

F

F

T

F

F

F

F

Possible input combinations for

"OR" truth table

P

Q

P

OR -

Q

T

T

T

F

F

T

F

F

F

T

T

T

Unique combination for the "Not"

Logic gates

Not -

P

P

T

F

F

T

QUIZ

What symbol is used for the "Not" logic gate?

What symbol is used the "AND" logic gate?

Which logic gate does this symbol represent? V

What is a statement?

Answer A or B

In the truth table:

A.

Is it many input combinations to get the result of one out put? Or

B.

Many output combinations to get one input

Homework

Name and draw the symbols for four other logic gates.

Due date February 2013

Opposite of the statement

(Conjunction)

(Negation)

(Disjunction statement)

Three types of logic circuits

D-Type Frequency Divider

Programmable Inverter

Edge triggered RS Flipflop

**Watch video**

Using "Not" transistor circuit

Using "Not" transistor circuit

http://www.neuroproductions.be/logic-lab/

Simulation of logic gates

Logic Gates

Design a leaflet explaining

about logic gates. The leaflet must include:

The truth table for "NOT", "AND", "OR"

The symbol for each of the above

Give reason why the truth table is used.

Learning Outcomes

All MUST able to simulate a combination using the online tutorial

Most s SHOULD: Explain the use of logic gates in engineering (leaflet)

Some COULD: Create multiple combination of input using the simulator

Watch how logic gates are used in circuits

Truth tables and logic

gates

What is the purpose of truth tables in engineering

How truth tables help in constructing digital circuitry

How truth tables and logic gates help when designing digital circuitry.

what is a digital circuit

Starter Activity

Match the internal component

Learning objectives

All must know the 3 basic logic gate operators.

Most should be able to utilise the Truth Table to work-out the output of given inputs.

Some could explain the use of Truth Tables for working-out the output of an input combination.

Logic gate operators act like gatekeepers.

Logic gate operators allow or dis-allow an electrical current in a circuit.

(In binary what does that mean?)

Logic gates are used to calculate an output depending on the combination of inputs.

Truth tables have of all the possible combinations for logic gate operators.

Example of a circuit

.

AND

NOT

OR

Logic gates

Truth tables

Truth tables contain the unique combinations for all the logic gate operators.

In this lesson we are looking at the basic 3 logic gates.

Starter Activity

Match the Internal Components

of a computer to the correct label.

Logic Gates

What are statements

Logic gates test statements giving the result to be either true or false

Logic gates' values are represented in Truth Tables.

In put

There are colours in the rainbow.

Ducks can swim.

The prime minister attended Kingford School.

Sunday is the first day of the week.

OutPut

yes

yes

yes

No

**Plenary**

**What is the name of this logic gate?**

**Homework**

**Find other logic gates**

**End of lesson**

**What information truth tables contain?**

**How many values a statement have?**

**What makes the decision to allow or dis-allow current to pass through a certain point in circuits.**

Demonstrating how the 3 basic logic gates work using volunteers

Call Register

Class Activity: Search Online

for the following:

What are logic gates?

What are Truth Tables?

What is a statement?

A statement is a meaning which has

only two values. It can either be true or false

Convert this table to Binary.

Convert this table to binary

Convert this table to binary

Watch video: Truth tables for

AND, OR and NOT logic gates