Introduction
Amplifiers are components in several devices, such as stereos, television and computers, which allow sound to be produced through speakers. Normally, the "amplifier" term is associated with stereos, or musical devices, most commonly.
Sound
Sound is produced when there is a vibration in the atmosphere. This vibration disturbs the air, causing air particles to bounce off other air particles, carrying the vibration throughout. We hear these changes in air pressure by translating the change to electrical signals that the brain can process.
Sound Equipment
Major components in electronic sound equipment are simply translators. This equipment uses a signal in one form and transfers it into another. The end product in the sound signal is translated into a physical sound wave which is its original form. There are three major steps in sound production. First, there is a diaphragm located in a microphone that is vibrated by moving sound waves. The vibration of the diaphragm is translated into an electrical signal. This signal changes show rarefactions and compressions of a sound wave. Then, a recorder translates the signal as a pattern in another form of medium, such as digital or analog tape. Lastly, a player of some kind is introduced to read the pattern as electrical signal and transfers the electricity to propel a speaker cone back and forth.
Amplification
Most steps of the sound process, such as the microphone and recorder require very little electrical current to be produced. The last step of the process, moving the speaker cone, does require more of a boost in current for the audio signal. This boost has to preserve the same pattern without any distortion of the original signal. The boost is created by an amplifier. The amplifier's sole purpose to to produce a more powerful audio signal in order to be heard through a speaker. Although amplifiers have just a simple purpose, the components that make then can be very complex.
Amplifier Components
The actual amplification process is complex. The amplifier does its job based on several different factors including the input signal, output signal, and power supply. For example, if the power supply is general household electricity, alternating current, then the amplifier must convert this to a battery type electricity, direct current. This is because in alternating current the power produces pulses of electricity and must be returned to the source and this would not work with a speaker and cone. The amplifier must also regulate the electrical current to ensure an even signal reaches the speaker.
Signal Circuits
There are two types of circuits that the amplifier must utilize; the output and the input circuits. The input circuit is an electrical signal that has been previously recorded by a microphone on some type of medium. This circuit supplies the amplifier with a varying signal that the amplifier uses to create the output signal. The output circuit is what the amplifier creates to send to the speaker. It uses the power supply to make a new signal that will match the original input signal but has the level of power that the speaker requires.
Tags: amplifier must, electrical signal, power supply, signal that, speaker cone, alternating current, audio signal