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20W audio amplifier using TDA7240

Description
The audio amplifier shown here is based on the TDA7240 IC from ST Microelectronics. The TDA 7240 is an integrated audio amplifier IC that can deliver 20 watts of audio output power into a 4ohm load. The IC has minimum external parts count and is available in the 7 pin compact Heptawatt package. The IC also has a lot of good features like loud speaker protection, short circuit protection, low noise, low distortion etc. The circuit can be operated from a 12V DC single power supply and this makes it very useful in car audio applications.

Circuit diagram.

 Notes.
  • Assemble the circuit on a good quality PCB.
  • Use 12V DC for powering the circuit.
  • K1 can be a 4 ohm, 20W speaker.
  • S1 is the standby switch and S2 is the ON/OFF switch.
  • LED D2 is a power ON indicator.
  • Fit the IC to a proper heatsink.