LM386 Audio amplifier Tutorial

[Agatha]

Here is a simple LM386 based audio amplifier circuit . It is built around popular amplifier LM386 (IC1), an 8-ohm, one-watt speaker (LS1), four capacitors and a few other components. A 6V battery is used to power this project.

Four electrolytic capacitors [two 10µF, 16V (C1 and C2) and two 220µF, 16V (C3 and C4)] are used in this circuit. C1 is connected to the middle terminal of 10k potmeter VR1. C2 is connected to pins 1 and 8 of IC1. Pin 5 of IC1 is its output terminal, which is connected to speaker LS1 through C3.

C4 is connected to the positive terminal of 6V battery and ground. Positive side of 6V is connected to pin 6 of IC1 and the other side to ground terminal to pin 4.

Circuit Diagram

LM386-power-Amp.jpg (38.62 KiB) Viewed 2001 times

Inverting pin 2 of IC1 is connected to ground and non-inverting pin 3 is connected to the input terminal through VR1. Audio input is fed to CON1. VR1 is used to control volume.
Construction and testing.

Circuit-Board-for-printing.jpg (26.53 KiB) Viewed 2001 times

Before using this project, test it using the 6V battery. Connect the 8-ohm, one-watt speaker to output pin 5 of IC1 through C3. Switch on S1 and keep VR1 to its mid position. Now, take a screwdriver and gently touch it on input terminal pin 3 of IC1. You should hear a humming sound from the speaker. This will confirm that your circuit is working and ready to use.

Let me know if this simple project helps. I will make another tutorial to improve this amplifier including some bass, trible etc