Many Electronic circuit projects in simple ways of learning

LM386 audio amplifier circuit with PCB

Though LM386 audio amplifiers are very old. But they still have a lot of useful.

Thanks, designer.

Imagine your audio player is weak sound. You want to increase sound up. They are a good choice. Because of the low voltage supply and work well with a battery.

Some may see its features in LM386 datasheet. Next, we learn for example of LM386 projects of 3 circuits.

Mini LM386 amplfier

If saving energy is important for you. This circuit is suitable. Because you can use it with a 9V battery at 5mA current. But give the gain of output to approx 50. Or the power of 300mW to 500mW at 8 ohms speaker.

LM386 audio amplifier circuit project


LM386 mini audio amplifier circuit

Imagine you make an AM receiver circuit. You can use this LM386 to amplify to a speaker 0.5W, 2 inches. With a 9V battery can listen sound for long.

Flexible of choosing parts
You can use similar devices. To instead each other.
For example:

  • The loudspeaker—use 4 ohms or 8 ohms. @ 0.25W or 0.5W. And any size as free space.
  • Voltage supply—use 4V to 12V. And low voltage low watts. It is correct.
  • The voltage of capacitors—use High voltage instead of low voltage. For example, C5 is an electrolytic capacitor. You may use 50V instead.
    But… Of course, it is more expensive.

Note:I will explain to you the working of these circuits.

In other circuits below.

How to builds

If you want to build these circuits. You can finish them on the universal PCB or even the breadboard.

But sometimes you want a PCB board. You can make it with a PCB layout and components layout.

lm386-audio-amplifier-pcb-layout
Figure 2 the PCB and components layout of the LM386 audio amplifier.

Parts lists
0.25W Resistors, tolerance: 5%
R1—10Ω
R2—1.2K
VR1—10K Potentiometer

Capacitors

C1, C2—0.1μF 50V Ceramic
C3,C4—10μF 25V Electrolytic
C5—220μF 16V Electrolytic

Semiconductors and others

IC1—LM386, Low voltage audio amplifier
SP1—8Ω 0.25W speaker
B1—Battery, 9V

9V Power Amplifier using LM386

Also, the above circuit. This one of the 9V amplifier circuit diagram. I like it. Because of high gain up to 200.

9V Power Amplifier using LM386

LM386 mini amplifier

How it works

To begin with, the signal goes to the input pin 3, non-inverting input. This is a signal amplifier in the non-return phase form.

They have…


  • The C1 absorbs this noise to protect the input.
  • And C2 increases the gain of the amplifier. If you want more gain. You can add more C2 value. But, more value, too distortion (should be lower 100uF).
  • The output comes out of pin 5 of IC1.
  • Then, through C4 coupling the stronger audio signals to better. And DC block and not passed to the speaker.

And while both R1 and C3 in series. They keep the high-frequency response better.
Parts lists
0.25W Resistors, tolerance: 5%
R1—10Ω
R2—1.2K
VR1—10K Potentiometer

Capacitors

C1—0.01μF 50V Ceramic
C2—10μF 25V Electrolytic
C3—0.1μF 50V Ceramic
C5—220μF 16V Electrolytic

Semiconductors and others

IC1—LM386, Low voltage audio amplifier
SP1—8Ω 0.25W speaker
B1—Battery, 9V

500 mW Power Amplifier using LM386N

Does it use with the 12V battery? Yes, LM386 can work within a car. Because of the long wide voltage supply range from 4V to 12V at 50mA only. Give power out of 500mW at 8 ohms speaker.

Some other features and the frequency response from 40Hz to 100 kHz rate. And the gain of 46 dB. And distortion Less than 1%.

500mW amplifier circuit project using 12V

How it works

First of all, Enter the power supply to the circuit. Then, LED1 lights up to show power on the circuit.

And, capacitors C6 and C7 filtered to smooth.

Then, Enter a signal to the input through C1.

It is the coupling signal to protect DC voltage noise in the circuit.

Next, the sound signal flows through VR1 to turn the volume up or down.

After that, the sound signal goes to pin 3 of IC1.

To increase the sound up. Then, the strong sound comes out of pin 5 through C5. It protects dc voltage and passes the low frequency better to power a loudspeaker.

The C4 and R1 are acting cut noise signal out away.

And, the pin 1 of IC1 has a jumper to access C3 to boost up to gain.
When the input signal is very small.
Parts lists
0.25W Resistors, tolerance: 5%
R1—10Ω
R2—1.2K
VR1—10K Potentiometer

Capacitors
C1—3.3μF 25V Electrolytic
C2, C6—0.1μF 50V Ceramic
C3—10μF 25V Electrolytic
C4—0.047μF 50V Ceramic
C5—470μF 16V Electrolytic
C7—100μF 25V Electrolytic

Semiconductors and others

IC1—LM386N4, Low voltage audio amplifier
LED1—Red LED 5mm.
SP1—8Ω 1W speaker
B1—Battery, 4V to 12V

Conclusion

We love LM386, me too. Because it uses a battery. We can test and make them more. It is easy and cheap. What do you think about it?

Keep Reading: LM386 Stereo Amplifier with Bridge model

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This Post Has 14 Comments

  1. Hi, I want to know how to give input, and can I use 3.5mm jack to input and use it with mp3 player

  2. How to give input plz tell fast????

  3. Hi,Shital
    Thanks for your feedback.
    You can use input for any low audio, example: CD audio, MP3, others.

  4. Hi! nice site i would like to ask ..Where i can find the block diagram or schematic diagram for making amp for tweeter and low driver

    High > need amp driver
    Mid > already have sound standard ex1200
    Low > need amp driver

  5. sir,pls tell me how to give input …???

  6. What is the size of this pcb?

  7. hello my name is mike , i am working on the project using the 555 ,but can anyone tell me which pin is whih and wheres does everything connect to because i have no idea where to connect each component to its belonging pin, if anyone can help please comment as soon as possible, thank you

  8. Hai can we connect two stage ic lm386 amplifier please send me circuit diagram of it to connect these stage with filter circuit and you site give very simple circuits thangs send me answer in my mail

  9. Hi shubhendu,
    Thanks for your visits.
    Please ser printer the pcb layout on 300dpi per inch.

  10. That was great.
    Tanks

  11. great …..!!!!!!!!!!!!!!!!!
    useful …… give a info for the audio amplifier using blootooth connector without audio jack

  12. email me small audio amp circuit

  13. i ve a 8 ohm 4 watt speaker what value of capacitance would i ve to use as zobel capacitor? when i searched through the net i found it to be inducatance/resistance^2 So actually how do i khow the henry of the speaker

  14. how to generate 85 dB sound?

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