Make the Smallest LM386 Amplifier Module

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Welcome again to another basic but useful instructable, in this time we'll show u how to create a mini amplifier with the LM386 IC, using minimal quantity of components and cables :)

Let's find out how to make it...

Supplies:

Step 1: Materials:

The materials you have to use are very easy to find in a electronics store like Radioshack or include you can use the "canibalism" in electronics to find out the components.

Materials Bill:

- LM386 MONO AMPLIFIER IC.

- SOCK FOR LM386 (OPTIONAL).

- LED 3mm (OPTIONAL).

- 0.050 nF ceramic capacitor (if u don't have exactly one, you can select a nearly value).

- 10 ohms @ 1/2 Watt resistor.

- 220 or more uF Electrolytic capacitor @ 25 V.

- 4 Male 90º (L) Headers for connection.

- 220, 330, 470 or 1k ohms resistor (for the led).

IF YOU ARE INTERESTED TO MAKE MORE AFFORDABLE AND DURABLE PROJECT YOU CAND DOWNLOAD FROM MY YOUTUBE VIDEO THE SCHEMATIC, PCB LAYOUT AND MAKE THE REAL ONE.

Aditional Materiales (for PCB Make only):

1- 2.5 cm x 2.5 cm Copper PCB onde side.

2- Ferrite chloridre for etching.

3- A Dremel for drilling the PCB.

4- Some related parts for etching, paper, PC, Lasser Printer, etc.

Let's find out the Electronic Schematic:

Step 2: Electronic Schematic and How to Work

First of all the circuit is proved and it really works well:

This circuit is in LM386 Texas Instruments Datasheet, it's the most easy and ver very low distorsion rate from almost all the circuits.

The gain is about 20.

The Power Out of this boys is Up to 1 Watt :)

I know there are out there some many differents IC Amps like the TDA2822, the purpose i decided to choose this one, is for the use in worldwide and easy to find in any electronic store of the planet :D

¿How it works?

The LM386M-1 and LM386MX-1 are power amplifiers

designed for use in low voltage consumer applications. The gain is internally set to 20 to keep external part count low, but the addition of an external resistor and capacitor between pins 1 and 8 will increase the gain to any value from 20 to 200. The inputs are ground referenced while the output automatically biases to one-half the supply voltage. The quiescent power drain is only 24 mW when operating from a 6-V supply, making the LM386M-1 and LM386MX-1 ideal for battery operation.

The LM386M-1 and LM386MX-1 are power amplifiers
designed for use in low voltage consumer applications. The gain is internally set to 20 to keep external part count low, but the addition of an external resistor and capacitor between pins 1 and 8 will increase the gain to any value from 20 to 200. The inputs are ground referenced while the output automatically biases to one-half the supply voltage. The quiescent power drain is only 24 mW when operating from a 6-V supply, making the LM386M-1 and LM386MX-1 ideal for battery operation.



Important note:


Step 3: Making It in PCB.

For a more durable project i really recommend to etching in a PCB the Layout of the circuit, you can download from my YouTube Video channel the layout and upper mask of components for a more "professional" ending :)

You can download the archive here ---->or in the ending of the video, where i explain to detail all the steps for to make the Micro Amplifier:

Please read some important anotations of the PCB Connections:

Pinout (front view to letf to right):

1- VCC (POSITIVE PIN 5 to 9 Volts DC).

2- Output (To 4 or 8 ohms 1 Watt speaker).

3- Input (Signal input) *In the next step i'll show u how to convert STEREO TO MONO for enjoy music directly from your cellphone.

4- GND (Negative terminal) *Please check it`s connected to the Negative Led and Capacitor polarity before solder it to PCB.

Step 4: Before Make Smoke Test...

Before finish it and try to make the "smoke test" :) check all the polarity and connections many times, this ensure not to make some mistakes:

CONVERTING STEREO TO MONO:

Almost all the modern electronic audio components like: iPods, iPhones, Android, Mp3 Players or any Music Sound Sources are Stereo:

The trick to make and hear all the side and music in a single speaker is "joint" audio source of both channel L and R. Llike the Picture:

R SIDE ---------[10 OHMS RESISTOR]-----INPUT TERMINAL OF THE MINI LM386 AMPLIFIER.

L SIDE ---------[10 OHMS RESISTOR]------SAME INPUT TERMINAL OF THE LM386 AMPLIFIER.

*This trick doesn't affect the functionality of the dispositive.

Step 5: Final Show...

One time you already check all, connect the the cables, input, and output in a protoboard to to make tke test.

IMPORTANT NOTES:

*if you hear some noise when you power up the amplifier ever before to feed the LM386 IC, put a 100 uF @ 25v electrolytic capacitor between VCC and GND Terminal to mute it.

*You and add and external 10 k Potentiometer for the "drive" the volume.

*As you see, sells some 3.5 mm Female headphone connect to to put in the protoboard directly, you and use on or connect as you want or have the materials disponibility :)

if you forgot to see my video here it is...World Smaller LM386 Amplifier module. (It is in Spanish for amigos and Bad hombres too).

That's all to today, don't forget to share, like, and suscribe me in instrutables, soon i'll make some funny electronic projects.

See you soon :)

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