Wireless Audio Amfplifier
CHAPTER ONE
INTRODUCTION TO WIRELESS AUDIO AMPLIFIER
1.1 BACKGROUND
The term amplifier refers to any device that increases the amplitude of a signal usually measured in voltage or current. This versatile device s used in a variety of different electronic applications. Especially in audio technology, a wide range of appliers can be produced based on product specifications (1e. Power, voltage, current). Currently, there are many types of audio amplifiers available for consumers. [1]
Sound signal amplification is used for instruments, such as the guitar or the bass. They are also used commonly in-home theater systems and with stereo speakers. The basic design behind all of these amplifiers s derived from the simplest concepts of circuit design.
for our project, we set out to constructs an audio amplifier. The inputs of our circuit were stereo signals from a portable music player. Although we used a low-power speaker, we needed to achieve approximately three times gain over the entre circuit. In addition, the amplifier had to be produced at a known cost with available materials. Before building the actual amplifier, we realized that we had to construct, simulate, and test the circuit. Each step was necessary to understand the concepts involved in amplification. [2]
AN AUDIO POWER AMPLIFIER (or power amp) is an electronic amplifier that amplifies low-power electronic audio signals such as the signal from radio receiver or electric guitar pickup to a level that is high enough for driving loudspeakers or headphones. Audio power amplifiers are found in all manner of sound systems including sound reinforcement, public address and home audio systems and musical instrument amplifiers like guitar amplifiers. It is the final electronic stage in a typical audio playback chain before the signal is sent to the loudspeakers. [3]
BLUETOOTH
As a technology, Bluetooth originated in [4] Sweden in the late 1990s. Its original purpose was to eliminate the need for unnecessary cable connections between devices from different manufacturers.
For example, if you have a smartphone from apple and a speaker from job or Bose, it could be difficult to get an audio signal from one to the other due to the fact that the two devices both have rather proprietary connections.
However, Bluetooth allows devices to connect to one another with short-range radio frequencies that alternate several hundred times a second. This also lends itself to security, making Bluetooth connection a very secure way for data to be transferred.
Bluetooth wireless technology (bwt) has nearly unlimited potential, especially in the internet of things, and is currently also used in smart speakers, smart home implementations, and several other devices.
WIRELESS BLUETOOTH AMPLIFIER
Understanding technology is a complicated uphill battle. Because there’s never any shortage of products brought to market, trying to stay on top of them can seem incredibly daunting. The Bluetooth headphone amp is one such product. Because it hasn’t been around for long, it’s a good idea to start by defining what it is.
1.2 STATEMENT OF PROBLEM
1. It has a tendency to become noisy with age especially in moist climate.
2. The voltage gain reduces at low as well as high frequencies.
3. It provides poor impedance matching and hence it cannot be used as a final stage of an amplifier.
Advantages:
1. It has wide frequency response and large bandwidth.
2. It is most convenient and least expensive amplifier.
3. It provides high audio fidelity.
4. It has low amplitude distortion.
5. It provides low frequency distortion.
1.3 AIMS AND OBJECTIVES
Aims and objectives
To construct cost-effective high-power audio amplifier.
To control the system via wireless Bluetooth module.
The overall objective of this project is to construct wireless audio amplifier whilst ensuring a high sound quality at all input frequencies and volume settings.
The housing for the circuitry and speakers must also be considered, it should be
Strong enough to withstand being moved about and sturdy as to ensure that it doesn't rattle when it is playing music. It should appear professionally made and with an interesting and unique design. It should be simple to use allowing it to be enjoyed by all consumers, of all ages, as well as having a high-quality sound output with minimal static, especially at the more common ranges of frequencies. The speaker system must have a wide range in volume, which must be easily controlled. Portability is not an issue as this is not to be designed as a portable amplifier, rather A semi-permanent loudspeaker system. The product is to have one speaker set up In stereo, with the input to be provided by an mp3 device. The one speaker will Have an internal resistance of 8 ohms each, with each wired to either the left or Right feed of the audio from the mp3 device jack. The amplifier will have a gain of 20db. The volume controls will be an analogue system using a potentiometer connecting both of the two speaker systems together to ensure consistency Throughout the listening experience. The system will be powered by one 12-volt battery which will be easily accessible for ease of access. To ensure that the power source does not drain over time, a switch will be connected to enable the whole system to be turned on and off. The housing for the speakers and for the circuitry will be of a unique design whilst still enabling for practicality in terms of connecting the mp3 device, volume control and powering the amplifier system on and off.
Applications:
1. It is used in the initial stages of public address (pa) amplifier systems.
2. It is used in stereo amplifier.
3. It is widely used as a voltage’s amplifier.
4. It is used in radio and card reader
1.4 METHODOLOGY:
The circuit is constructed by using tda2822 (ic), and two major component which consist of speaker and battery. Where pin one is connected to a 220uf capacitor together with a speaker to the ground and produce output. And pin two +vcc which is the power supply to the circuit. And pin four is move directly to the ground and pin five 10uf is directly to the ground together with 1k-15k resistor that come from pin six+. The 15k resistor are connected to the ceramic capacitor100uf also is connected with 10k variable resistor that move to the ground. The pin seven+ 15k resistor is connected where ceramic capacitor100uf are attach to it with variable resistor 10k is connected to it and directly move to the ground where 1k resistor is connected to the 15k that comes from pin seven (7) and move to the ground. Where left and right of variable resistor are connected together. The last pin which is pin eight (8) is connected with 10uf capacitor to ground.
1.5 SIGNIFICANCE OF THE PROJECT
Significance of using audio power amplifiers
Let us discuss here in detail about power amplifiers but for that we need to know what the term amplifier. It is used to take an input signal and increase its amplitude. These amplifiers find use in all major kinds of electronic devices which are designed to perform many functions. There are various types of amplifiers available in the market and each one has its own specific utility. Take example of a radio transmitter which uses an rf amplifier which is designed to amplify a signal to drive an antenna. The power amplifiers are designed to drive loudspeakers.
In simple terms let us make you understand the purpose of using power amplifier; it takes signal from a source device which is then used at the transmitter end to drive a loudspeaker receiver such as those found here. It simply increases the amplitude of the input signal and drives it to the output end without any signal power l oss.
However, the signal received at the receiver end of all audio amplifiers contain many unwanted components that were not present at the transmission end which is called as the distortion. There are many types of distortion let us not go deep into that. One type of distortion creates noise that is heard by all of us at the background which does not allow the music to be played.
1.6 SCOPE OF THE PROJECT
Scope of the report
An audio amplifier is an electronic amplifier, which amplifies low-power electronic audio signals, such as the signal from a radio receiver to a level that is high enough for loudspeakers or headphones.
1.7 REPORT OUTLINE
This section describes the introduction part of our project. It introduce basic concept of audio amplifier wireless performance using a minimum amount of power of bandwidth. The second chapter explain literature review. It include background history of audio amplifier previous studies and theories used to guide during our project. The third chapter discourse the constructions and analysis of the body of the project. Its explain block diagram, calculation component value, schematic diagrams and result. The fourth chapter explain the value test carries out the result in tabular format and the discussion from the result. Finally the project also include conclusion, limitation, recommendation, references. [5]
CHAPTER TWO:
LITERATURE REVIEW
The previous tutorials, the amplifier circuits to boost audio from a single channel were designed. Over the last decade, there is growth in the audiophile. This has brought a revolution in the music industry. Now, people like to hear the high-resolution surround music just like a 3d video. A surround sound system is designed to create a sound field like the sound is coming from back, front, left and right sides. It can also create the sound above the listener. The surround sound system is used in cinemas and drama theaters to give a realistic feeling to the audience. An alternative to the surround sound system is stereo audio system. [6].
There are basically two sound systems –
1) mono sound system- the mono system produces a mono-natural sound which comes from a single channel and is reproduced by a single speaker. Though a greater number of speakers can be added to play the same audio channel but a copy of the same sound will be played on all the speakers in such system.
2) stereo sound system – in the stereo sound system, the stereophonic sound, also known as stereo sound, can be heard by different channels using more than one speaker. Generally, by the stereo system, it is meant that there are two independent audio channels which are reproduced by two or more speakers separately. Such a system is widely used in head phones. For designing a stereo sound system there are two channels required as well as the audio source is required which can provide the stereo sound. So that the audio signal from two audio channels could be obtained and the sound can be reproduced at different speakers. [7]
For a stereo sound system, the same number of amplifiers are required as the number of audio channels. In this tutorial, a stereo power audio amplifier will be designed using tda2822 ic. Tda2822 is a dual power amplifier having two independent amplifier circuits on the same chip. The ic can be used as bridge or stereo audio amplifier.[8]
In the circuit designed in this tutorial, the ic is used as stereo power amplifier to boost to audio channels and output audio to two separate speakers.
In the introductory article of this series, various design parameters of the audio amplifier circuits were discussed like gain, volume, skew rate, linearity, bandwidth, clipping effect, stability, efficiency, snr, output power, thd and loop grounding. This amplifier circuit will be designed considering the following design parameters –
Gain (voltage) – 39 db
Bandwidth – 20 hz to 20 khz
Output power – 1 watt
The amplifier will be designed to supply audio to two speakers having an impedance of 8 ohms. The circuit will have the following additional features –
– no clipping effects
– stereo output
The designing of the circuit will be followed by testing of the circuit for the verification of the intended design factors
Component required
CHAPTER THREE
3.1 SYSTEM'S DESCRIPTION
The amplifier circuit is built by assembling the following components together –
Circuit connections –
1) DC SOURCE – the amplifier circuit is powered by a battery of 3.7v and 1.5 a rating. The power supply is passed through a capacitor (shown as c3 in the circuit diagram) of 10uf. This is a filtering capacitor to remove any unwanted ripples from the power source.
2) AUDIO SOURCE – the audio input is provided from a smart phone. For receiving audio from the smart phone, an audio jack of 3.5 mm is plugged into the phone. The 3.5 mm audio jack has three wires – one for ground and two wires for left and right channel. As the amplifier is designed for both channels, both of the channel wires will be connected to the amplifier as audio input. Both the channels are used for applying the stereo sound to the input of the amplifier. The ground wire of the jack will be connected to the common ground of the circuit. Generally, the audio signals on such two channels are out of phase by 180 degrees making the system a balanced audio system. [9].
3) SPEAKER
A speaker is a device that use to convert electrical signal or electro- magnetic waves into sound energy
4)AMPLIFIER
An amplifier is an electronics device which use to boost the level of alectric signal from one stage to another
5) VOLUME CARDS are electrical programmable devices that use to control/ regulate the volume of a system
3.2 FUNCTIONAL COMPONENTS
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses. High-power resistors that can dissipate many watts of electrical power as heat, may be used as part of motor controls, in power distribution systems, or as test loads for generators. Fixed resistors have resistances that only change slightly with temperature, time or operating voltage. Variable resistors can be used to adjust circuit elements (such as a volume control or a lamp dimmer), or as sensing devices for heat, light, humidity, force, or chemical activity. Sejdic, E. and Mickle, M. (2015).
Date: 2026-08-14 00:00:00.000000