Voice Amplifier Circuit Using TDA2003 Amplifier IC

A Voice amplifier circuit is an electronic amplifier that amplifies low-power audio signals such as the signal from a radio receiver or a microphone to a level that is strong enough for driving loudspeakers or headphones. Different kinds of sound systems such as sound reinforcement systems, public address, speech systems & musical instrument amplifiers like guitar amplifiers use different types of audio amplifiers. In this project. We will design a 10W Voice amplifier circuit using a TDA2003 audio amplifier IC.

TDA2003 is a general-purpose audio amplifier circuit IC for stereo or mono audio design circuits. This amplifier IC can output up to 3.5A current to drive speakers & can also handle high currents up to 5A for a shorter duration without any damage. It can also handle short circuits in both AC & DC rails without damaging itself. It has an operating voltage of 18V but can handle high voltages up to 28V. This makes it robust to be used in automotive audio designs such as car stereos.

Hardware Component

you will need the following parts to build this project

S.no	Component	Value	Qty
1.	Breadboard	–	1
2.	Electrolytic Capacitor	0uF, 470uF, 1000uF	1, 1, 2
3.	Battery	9v	1
4.	Audio Amp IC	TDA2003	1
5.	Ceramic Capacitors	100nF/63V, 1822pF	1
6.	Resistor	470Ω, 100Ω, 47Ω, 1Ω	1
7.	Speaker	4 ohm	1

TDA2003 Pinout

Pin No.	Pin name	Description
1	Non – Inverting Input	Non-inverting end (+ve) of Amplifier
2	Inverting Input	Inverting end (-ve) of Amplifier
3	GND	Connect to the ground of the circuit
4	OUT	Outputs the amplified signal
5	Supply Voltage	Supply voltage, Minimum 6V & Maximum 28V

Circuit Diagram

Working Explanation

The heart of this circuit is a TDA2003 amplifier IC. Voice amplifiers are generally used to address a large group or audience. There are 2 stages to the operation of this circuit. The Preamp stage & the Amplifier stage. In the first stage, the audio input comes from the electret microphone. Here, a Capacitor (10μF) blocks the DC component, allowing the AC component to flow to the base of the transistor amplifier(2N3904). The transistor amplifies the weak AC audio signal and sends it to Pin 1 of the TDA23003 IC.

Now in the 2nd stage, the TDA2003 IC receives the input signal from the preamp stage. It further amplifies the audio signal and sends it to an audio transducer such as a loudspeaker

Applications

• Generally used in devices designed for people with deficiencies such as vocal chord damage & throat/voice problems.
• Commonly used in devices such as radio amplifiers & Speech amplifiers.