Power Supply and Audio Amplifier

Overview

Built and characterized a variable AC-DC power supply and speaker amplifier system across analog and power electronics labs.

What I Built

• Variable AC-DC supply
• Rectifier and capacitive filter stages
• Zener regulation
• Potentiometer-based output control
• MOSFET source-follower buffering
• Discrete MOSFET amplifier stage
• TPA3122D2 Class-D audio amplifier
• LC output filtering and speaker-load testing

Technical Details

The power supply converted AC input into an adjustable DC output using rectification, smoothing, Zener regulation, and source-follower buffering. The audio amplifier work included discrete MOSFET amplifier testing and a Class-D amplifier stage using the TPA3122D2. The amplifier was tested under speaker-emulation loads.

My Role

Daniel assembled, tested, and characterized the supply and amplifier circuits, using lab instruments to validate output behavior and performance.

Challenges and Debugging

• Managing load regulation in the variable supply
• Understanding source-follower buffering and output resistance
• Measuring distortion and frequency response
• Testing thermal behavior under load
• Debugging soldered circuit behavior and component placement

Results

• Built adjustable power supply for downstream audio circuitry
• Measured output waveforms, THD, frequency response, efficiency, load power, and thermal behavior
• Demonstrated audio amplifier behavior under speaker-emulation loads

Tools and Skills