DESIGN AND CONSTRUCTION OF A 60 WATTS POWER AMPLIFIER
ONYEKE CHIAMAKA EE/N2003/361
Department of Electrical/Electronic Engineering
An audio AMP is basically a system which is used as a means of increasing the level of sound or audio signals for maximum use.
A public address system consists basically of microphone, Amplifier and speaker(s) to facilitate the communication to intelligible speech to groups of people or an audience. The main purpose of providing sound reinforcement indoors with sufficient high â€“ fidelity being the coverage of large groups with unobstrusive sound system. Directional horns are often employed in outdoor systems to concentrate sound energy efficiently over the areas served. Intelligibility may be the performance criteria for an indoor system such as an air waiting room. On the other hand, high fidelity reproduction is required for sound reinforcement system for instance, a conference hall, or a class room.
Most power amplifiers of a public address system have provisions for one or more microphones and one or other sound sources such as FM, AM radio tuner output, tape recorder and record player generally tagged auxiliary sound sources. Level traders or volume contracts are provided to adjust the volume of each of those sources independently.
In this project, the concentration of a high fidelity (H1 â€“ F1) power amplifier for the in public address system.
This amplifier is designed as a unit utilizing three input sources. Operating controls are provided for each input source with the possibility of mixing the three input sources depending on the setting of the operating or gain controls.
This flexibility of mixer operation is without sudden increase or decrease in volume.
TABLE OF CONTENTS
1.0 Power Amplifiers
1.1 Power Supply
1.2 The Preamplifier
1.3 Impedance Matching, Signal and Equalization
2.0 Methods of Cooling the System
2.1 Perforation of the Panel
2.2 Power Transistor Heat Sink
2.3 External Cooling
3.0 Trouble Shooting of the Power AMP
3.1 Preliminary Checks
3.2 Likely Faults
3.3 No Output, Reduced Output, Distortion & Noise Intermittence
4.0 The Console
4.3 Circuit Layout
4.4 Components Lists & Values