Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/shubhamatkal/4-bit-adder-using-transistors


https://github.com/shubhamatkal/4-bit-adder-using-transistors

Last synced: 9 days ago
JSON representation

Awesome Lists containing this project

README 

        

# 4-bit Adder Using Transistors



This project demonstrates the construction of a 4-bit adder using BC547 transistors, resistors, LEDs, and other components on breadboards. The adder takes two 4-bit binary numbers as input and provides a 5-bit binary result displayed using LEDs.



### [demo video link](https://youtu.be/X30VRVgSusA?si=7kjyowYuODl_7c2p)



## Table of Contents

- [Components](#components)

- [Circuit Design](#circuit-design)

- [Adder Logic](#adder-logic)

- [Breadboard Layout](#breadboard-layout)

- [Assembly Instructions](#assembly-instructions)

- [Examples](#examples)

- [Testing](#testing)

- [Troubleshooting](#troubleshooting)

- [Conclusion](#conclusion)



## Components



- **6 Breadboards (800 pins each)**

- **BC547 Transistors (100 pieces)**

- **Jumper Wires (100 pieces)**

- **Resistors:**

  - 220k ohm (100 pieces)

  - 47k ohm (50 pieces)

- **9V Batteries (2 pieces, connected in parallel)**

- **5mm LEDs (13 pieces)**

- **Push Buttons (optional, for input)**

- **Battery Holders**

- **Connecting Wires**



## Circuit Design



The adder is constructed using the following gates for each bit addition:

- **2 XOR gates** for the sum

- **2 AND gates** for generating carry

- **1 OR gate** for combining the carries



Each gate is built using BC547 transistors.



### XOR Gate (Sum Calculation)

- **Transistors:** 2

- **Resistors:** 47k ohm (2 pieces)



### AND Gate (Carry Generation)

- **Transistors:** 2

- **Resistors:** 220k ohm (2 pieces)



### OR Gate (Carry Combination)

- **Transistors:** 1

- **Resistors:** 47k ohm (1 piece)



## Breadboard Layout



Use the following layout for each 4-bit adder section:



1. **Place transistors** on the breadboard.

2. **Connect resistors** to the base of each transistor as per gate requirement.

3. **Connect the emitters** to ground.

4. **Connect the collectors** to the LEDs and then to Vcc through appropriate resistors.

5. **Arrange the inputs** using jumper wires.



## Assembly Instructions



1. **Power Supply:** Connect the 9V batteries in parallel to ensure a stable power supply.

2. **Place Components:** Place transistors, resistors, and LEDs on the breadboards according to the circuit design.

3. **Wiring:** Use jumper wires to connect the components, following the breadboard layout.

4. **Testing Inputs:** Optionally, use push buttons to simulate binary inputs.

5. **Verify Connections:** Ensure all connections are secure and correct.



## Examples



Here are examples of input and output for the 4-bit adder:



- **Example 1:**

  - Input: A = 0101 (5), B = 0011 (3)

  - Output: Sum = 1000 (8)



- **Example 2:**

  - Input: A = 1111 (15), B = 0001 (1)

  - Output: Sum = 10000 (16)



- **Example 3:**

  - Input: A = 1010 (10), B = 0101 (5)

  - Output: Sum = 1111 (15)



## Testing



1. **Apply Inputs:** Provide binary inputs through the input lines.

2. **Observe Outputs:** Check the LED outputs for the sum and carry.

3. **Verify Results:** Compare the LED outputs with expected binary results.



## Troubleshooting



- **No Output:** Check power supply and connections.

- **Incorrect Output:** Verify the arrangement of transistors and resistors.

- **LEDs Not Lighting:** Check the LED connections and ensure they are not reversed.



## Conclusion



This project successfully demonstrates the construction of a 4-bit adder using transistors. By following the circuit design and assembly instructions, you can understand the fundamental working of digital circuits and logic gates.



---



**Note:** Ensure safety while working with electronic components and follow proper guidelines to avoid damage or injury.