This is just another 20W audio amplifier circuit , but this time
based on the LM1875 audio amplifier IC from National Semiconductors. With a 25V
dual power supply LM1875 can deliver 20W of audio power into a 4 ohm speaker.
The LM1875 requires very less external components and has very low distortion.
The IC is also packed with a lot good features like fast slew rate, wide supply
voltage range, high output current, high output voltage swing, thermal
protection etc. The IC is available in TO-220 plastic power package and is well
suitable for a variety of applications like audio systems, servo amplifiers,
home theatre systems etc.
Circuit diagram
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Notes.
- Assemble the circuit on a good quality PCB.
- Use +/-25V DC dual supply for powering the circuit.
- K1 can be 4 ohm, 20W speaker.
- A proper heat sink is necessary for the IC.
- F1 and F2 are 2A fuses
