Audio Amplifier

This audio amplifier project was created in my microelectronics lab for the final project. The objective of the project was to build an audio amplifier that can play music through headphones using an external music player. The process of building the amplifier started by picking components and designing the complete electrical schematic on EAGLE.

Once the components were correctly chosen the printed circuit board was designed and routed using EAGLE. The total electrical system was broken down into three main sub systems: left channel, right channel, and power supply. Both the left and right channels are provided the audio signal and the audio operational amplifier manages the signal. The power supply is designed to provide 15 volts to each channel. The final step was to solder the components on the PCB and conduct the board testing. During board testing I conducted trouble shooting by using a digital multi meter to observe if components were receiving the correct amount of power.

The power supply is responsible for converting the AC power that comes into the board to the necessary +/- 15 volts for the operational amplifier power rails. The AC power is regulated and rectified using a series of diodes, resistors, and capacitors. The power supply components have much larger values of capacitance and resistance to handle and regulate the high power signal.

The right and left channel are responsible for receiving the audio signal then passing it through to the operational amplifier. The signal is also passed though various components including capacitors, resistors, diodes, and transistors. Both of the operational amplifier output signals are sent to the headphone audio jack.