# Logic Gates Demonstration

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## Introduction: Logic Gates Demonstration

Here's my first DIY instructable, for explaining the functioning of
Basic Logic Gates(NOT, AND & OR) using simple push-button and LEDs.

A Digital Logic Gate is an electronic device that makes
logical decisions based on the different combinations of digital signals present on its inputs. Digital logic gates may have more than one input but generally only have one digital output. Individual logic gates can be connected together to form combinational or sequential circuits, or larger logic gate functions.

The Digital Logic Gate is the basic building block
from which all digital electronic circuits and microprocessor based systems are constructed from. Basic digital logic gates perform logical operations of AND, OR and NOT on binary numbers.

In digital logic design only two voltage levels or states are allowed and these states are generally referred to as Logic “1” and Logic “0”, High and Low, or True and False. These two states are represented in Boolean Algebra and standard truth tables by the binary digits of “1” and “0” respectively.

Enough Theory, now its time for some practical.

## Step 1: Assemble Equipments and Components

Let's Begin.

First step first, assemble the equipments and components required for the project.

Here's what you need:

1. 1 LEDs X 8
2. Push buttons X 10
3. 330 ohm resistors x 8
4. 9 volt battery X 2
5. wires(red, black, yellow, green) X 2 meters each
6. Perfboards(3.5"x3") X 3
7. Solderings machine, Flux and Solder iron

See the illustrations.

(I know, I know, its bit of a messy, but you know, such projects make your table look horrible, and am also not very good at presenting things, but all we want is our project working)

## Step 2: For the NOT Gate

• On a Perfboard arrange the components( 2 LEDs, 2 Pushbuttons and 2 resistors) as shown.
• The soldering should be done by making the appropriate connections.
• connect the +ve terminal of LED(the longer terminal) with the resistor.
• The circuit diagram as shown is for Simplicity.
• After connections and soldering is done, connect the batteries at respective terminals, and we are ready.
• Both Buttons are to be pressed simultaneously for indicating input.
• You can refer to the Truth Table given.

## Step 3: AND Gate

• On a Perfboard arrange the components( 3 LEDs, 4 Pushbuttons and 3 resistors) as shown.
• The soldering should be done by making the appropriate connections. connect the +ve terminal of LED(the longer terminal) with the resistor.
• The circuit diagram as shown is for Simplicity.
• After connections and soldering is done, connect the batteries at respective terminals, and we are ready.
• Both Buttons are to be pressed simultaneously for indicating input.
• You can refer to the Truth Table given.

## Step 4: OR Gate

• On a Perfboard arrange the components(3 LEDs, 4 Pushbuttons and 3 resistors) as shown.
• The soldering should be done by making the appropriate connections.
• connect the +ve terminal of LED(the longer terminal) with the resistor.
• The circuit diagram as shown is for Simplicity.After connections and soldering is done, connect the batteries at respective terminals, and we are ready.
• Both Buttons are to be pressed simultaneously for indicating input.
• You can refer to the Truth Table given.

## Step 5: Finally...

You can connect all the Positive and Negative terminals to one, I have done it.

Looks some what like this.

The wires can be at times messy, but that's not really a big deal.

Hope, you find this informative and useful.

Thanks for having a look at this.

Bye for now.

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