This necessities the use of a public address system(PA). The PA system requires special design as they must be tailor made to meet the client's specifications and wants. It is therefore necessary to design the PA systems using an organized procedure such as the Pahl and Beitz method. The process involves the surveying of the customer's needs and wants, generating some demands and wishes from the client, developing of the solution using a function analysis matrix and finally developing the product using the information from the demands and the function analysis. After the development of the product, it is tested for its overall suitability particular in satisfying the customers wants and needs, if the product is found unsuitable or with some limits, it is necessary to redesign and reconfigure the product to ensure that it satisfy the customer needs and promotes usability engineering and ergonomic principles.
The power supply: This is the system that supplies the public address unit with electrical power that is used to run the whole PA system. The most common types power supplied include the alternating current (AC) and the direct current (DC). Most PA system use direct current while most of the commercially available power is in form of AC supplied at 240 Volts or 110 volts.
Rectifier unit or DC adapter
This adapter is used for the conversion of AC power to DC power. Some of the PA systems incorporate this gadget inside the systems while others have the same system incorporated outside as a separate unit
The amplifier unit
The amplifier unit is used for amplification of the voice signal. The amplifier receives low power electrical signal and amplify the signals to high power and voltage which is fed to the loud speaker systems. Amplifier uses the transistors, MOSFET devices, field effects transistors (FET), CMOS and operational amplifiers circuit to provide gain to the input signal.
The microphone unit
The microphone unit is used for changing voice sound to an electrical signal that can be amplified by the amplifier. Upon receiving the sound signal, the crystal microphone vibrate generating a small electrical current that is fed to the amplifier
The mixer is used for signal conditioning, this helps is controlling the voice produced by the amplifier unit. The mixer enhances the audibility of the sound