The thesis encompasses the theoretical background, design and production of the printed circuit board (PCB) for a power audio amplifier. The circuit is tested with simulation tools before designing the PCB. This is followed by prototype implementation, PCB fabrication, and completion of the circuit by soldering the components.
During the simulation with the SPICE software tool and the practical testing of the prototype circuit, we encountered limitations for which we found solutions and modified the circuit accordingly. We changed the topology of the circuit to ensure greater stability.
The circuit consists of an operational amplifier with an input filter, followed by a class AB output amplifier stage in a Darlington configuration. The circuit features an adjustable feedback loop that determines the gain. The bias voltage is also adjustable, which affects the distortion of the amplified output signal and thus the quality of the amplifier.
Due to the relatively high power consumption of the class AB amplifier, we designed the final version of the PCB to be mountable on a heatsink with a fan using spacers for proper heat dissipation. The fan has an adjustable speed regulation circuit.
We conducted measurements to verify the performance of the circuit and to gain insight into possible improvements.
|
