Mini Audio amplifier Circuits comes into play whenever we like to take music wherever we go. These kind of mini audio amplifier will make the music system light and can be moved from one place to another. Also these kind of amplifiers will reduce the cost without compromising the performance of the music system. The above system was built using a mono BTL output amplifier IC TDA7502.
The IC TDA7502 is a mono BTL output amplifiers which is best suited to use with portable recorder, radios and other mini audio devices. This IC operates with 4.5 to 18V and comes with internal DC volume control. The maximum gain of the amplfier is fixed at 35.5 db and can be altered using Volume Control (VC) pin. This amplifier is capable of driving load of 2 to 3W and will suit perfectly to drive a 8 ohm speaker with a supply of 6V. See detailed description about this IC in Datasheet here.
WORKING OF MINI AUDIO AMPLIFIER CIRCUIT:
The IC TDA7502 is the heart of this circuit which serves the purpose of amplification. A variable resistor RV1 is used in order to control the volume of the audio signal. Since the volume control was done using RV1, 4th pin Volume Control VC was left unconnected in the above schematic.
The capacitor C1 and C2 was used to filter the supply voltage and can be eliminated if a battery was used. And the output part comes with a simple 8 Ohms 2Watt speaker. Make sure you select appropriate speaker for this mini amplifier since the chip can only drive up to 3Watt with a 6V supply. If you use high load speakers you may end up smoking the amplifier IC.