Analog Sound Frequency LED Indicator

Proteus Simulation & PCB Design Project

This project presents an analog electronic circuit that visualizes sound frequencies using LEDs.

The system detects sound signals through a microphone, processes the signal using RC filters, and drives LEDs using transistor amplification. Different LEDs respond to different frequency ranges, allowing the circuit to represent low, medium, and high frequency sounds visually.

Project Features

• Analog sound signal processing
• RC frequency filtering
• Transistor amplification
• Frequency-based LED visualization
• PCB design and implementation
• Designed and simulated in Proteus

How the Circuit Works

1. Microphone converts sound waves into electrical signals.

2. RC filters separate different frequency components of the sound signal.

3. BC546 transistors amplify the filtered signals.

4. LEDs indicate different frequency ranges:

• Red LED → Low frequencies
• Green LED → Medium frequencies
• Blue LED → High frequencies

Components Used

• BC546 Transistors
• Resistors
• Capacitor (22nF)
• Microphone
• LEDs
• 9V Power Supply

Engineering Design Process

1. Circuit schematic design in Proteus
2. Circuit simulation
3. PCB layout design
4. PCB manufacturing
5. Component soldering
6. Circuit testing

Project Report

Detailed explanation of the circuit design, calculations and PCB manufacturing process can be found in the project report.

---

Project Images

Proteus Circuit Design

PCB Layout

3D PCB View (Front)

3D PCB View (Back)

Copper Board Before Etching

PCB Etching Process

PCB Drilling

Component Soldering

Final PCB

Author

Elif Tütüncü
Electrical & Electronics Engineering Student