Problem StatementMany amplifiers are being used today to increase to quality and quantity of sound. There are many different applications in which amplifiers are used. Many manufacturers market their products based on features that are provided with the amplifier. They use these features as a main attraction of customers to their products. People who are interested in increasing the sound quality of either their home entertainment system or caraudio system are the main customers of audio amplifiers. Many customers are searching for the best amplifier that can produce the best quality sound. Therefore, amplifiers that use digital filtering are becoming more in demand by customers than analog systems. Our goal is to design and construct a portable amplifier that will meet the needs of our customers.An amplifier is an electronic device that increases the voltage, current, or power of a signal. An amplifier is categorized as either a weak signal amplifier or a power amplifier.Weak signal amplifiers are primarily wireless receivers such as acoustic pickups, audio tape players, and compact discs. Usually, weak signal amplifiers are designed for small inputs. The power rating of a weak signal amplifier tends to be measured in milliwatts (mW). Power amplifiers are primarily used for high demand for power to the load (speaker). Home theaters systems, car audio systems, and musical equipment are examples of the use of power amplifiers. A power amplifier usually produces a much higher output power rating which is measured in watts (W).Amplifiers are used in a number of applications. In modern days, the slogan of “the louder the better” tends to be main focus in the design process of amplifiers that are beingproduced today. The steady rise in DVD sales has increased the demand of home theater systems. A home theater system basically consists of an amplifier and speakers. The amplifier takes a signal from either the television or DVD player and amplifies the signal into the speakers. The speakers may be placed in different areas of a room to produce surround sound. Amplifiers are regularly used in enhancing the sound quality of car audiosystems. In a car audio system, the amplifier takes the signal from the head unit (car stereo) and amplifies the signal enough to drive car speakers. Car speakers can range from 10-200 W, which are power ratings for normal size speakers. Also subwoofers can be considered as car speakers. They can have ratings that can range from 200-2000 W. Some musicians use amplifiers to amplify the signals of their instruments to increase the sound at different events, such as parties and concerts. Tape recorders and personal compact disc players use smaller amplifiers. Their amplifiers are so small that they are usually built into the device.Power amplifiers on the markets today usually have special features. Features are added to attract the customer to buy their products. Features may consist of volume, balance, bass, displays, load matching, and treble controllers. Some amplifiers give the user an option to control the crossover factor between the high and low output signals. Thermal and overload protection modes have become a major factor to customers recently. Thermal protection mode helps prevent the amplifier from overheating by shutting off theamplifier when it has reached a certain temperature. Overheating can result in extremedamage to the components of the amplifier. Overload protection mode helps prevent to the user from dropping below the minimum impedance. This feature operates much like the thermal mode in that it shuts off the amplifier when the impedance of the load is not in balance. Many of the power amplifiers in today’s society are not portable. They are either mounted close to their voltage source or plugged into an outlet. In recent years, there has been an increase in converting signals from analog to digital. The main reason for this is that a digital signal is more discrete than an analog signal. This means that a digital signal will be more crisp and clearer than an analog signal. Filtering a digital signal is much more efficient than filtering an analog signal. With an analog signal, noise within the signal itself plays an important part in the quality of the sound. The noise can result in a large amount of distortion in the sound that is produced within the speakers. Although producing digital signal is more expensive than that of an analog signal, the overall best quality sound will come from a digital signal. The device in which we plan to design will be designated for all individuals who enjoy the best quality of sound. To obtain a high quality sound, the amplifier will take advantage of a modern day technology signal processing technique, known as digital filtering. Digital filtering allows the incoming signal’s tone and soundness to be improved and reduces the distortion of the signal. The incoming signal will be filtered to only allow frequencies in the range of 20Hz to 20 kHz to pass through the filter. This range of frequencies is the frequencies in which audio signals operate in. Also by using digital filtering, the signal to noise ratio of the signal will be improved.There are three features that separate the amplifier we plan to design from the ones currently on the market. The features will include the option of impedance matching, displaying of the gain in decibels, and portability of the amplifier. Most amplifiers on themarket today are designed only for specific impedance speaker loads. The amplifier that we plan to design will have the option to choose between different impedance loads. Theamplifier will allow the user to choose a speaker with an impedance of 4 ohms or 8 ohms and perform at the same power output for both impedance loads. The second feature that the amplifier has is the displaying of the gain. This is a feature that is not normally included with some of the amplifiers on the market. This feature can result in a large number of sales. The third feature will include the portability and the compact size of theamplifier. Our amplifier will be designed to be easily transported and stored. We plan to design our amplifier to be confined to a 6” X 9” area.There are many different amplifiers on the market today. Our main objective is to design and construct a portable amplifier that will be suitable for our customers and also will meet their needs. The main features of
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