This small audio amplifier driven by the LM386 IC provides anywhere between 0.25 Watts - 1 Watt.
This specific circuit operates on 4 - 12 Volts ( Provide 9-12 Volts for optimum output ) and spits about 700mW of power.
The circuit is specially designed to filter out all the noises.
Step 1: THE TEST
Step 2: SELECTING YOUR IC:
The LM386 comes in three different output power levels :
1 ) LM386N-1 : 325 mW ( Milli Watts)
2) LM386N-3 : 700 mW
3) LM386n-4 : 1W
Step 3: SELECTING YOUR SPEAKER:
It is always a good choice to go with a FRS ( Full Range Speaker ) to reach the peak power levels and to get a soothing sound.
Go for a speaker with an impedance of 3 - 8 Ohms and an output power of 10W or less.
I will be using a 3 Ohms 10 Watts 2 inch speaker manufactured by Sony.
NOTE: AN EXCELLENT SPEAKER DRIVER LEFT TO STANDALONE WITHOUT A CASING WILL NOT PERFORM IT'S BEST. A PROPERLY ENCLOSED SPEAKER WILL ENSURE LOUDNESS AND SOUND CLARITY.
Step 4: THE PARTS LIST
1) Medium sized breadboard
Worldwide Link: http://www.ebay.com/itm/1PCS-Mini-Prototype-Solder...
2) 1 * LM386 IC
Worldwide Link: http://www.ebay.com/itm/50PCS-LM386-LM386N-DIP-8-...
Indian Link: http://www.ebay.in/itm/10-x-LM386-Low-Voltage-Aud...
3) 1 * 10K Potentiometer
4) 1 * 10uf Electrolytic capacitor
5) 1 * 100uf Electrolytic capacitor
6) 1 * 1000uf Electrolytic capacitor
7) 1 * 3.5mm Mono Audio pin
8) 1* 3.5mm Audio jack ( Both stereo and mono will work )
9) 1* Speaker driver ( 4 Ohms 3 Watts FRS 2 Inch )
Worldwide Link: http://www.ebay.com/itm/1pcs-2-inch-Full-Range-ne...
Indian Link: http://www.ebay.in/itm/2pcs-lot-3W-3-Watts-4-Ohms...
10) 1* DC Power jack
11) 1* DC Power plug
12) 1* 9V cell
13) 1* 9V cell power clip
14) A strip of Male to male Header pins ( 40 pins)
Step 5: THE CIRCUIT
Audio signal gets filtered first by a 10uf electrolytic capacitor and it is fed to a 10K potentiometer. This potentiometer acts as the volume regulator.
The signal from the potentiometer( center pin) is directly fed to the IC's INPUT ( PIN 3).
OUTPUT ( PIN 5) signal fed to a 1000uf electrolytic capacitor and the final signal is sent to the audio jack.
The power supply( +ve) is connected to Vs( PIN 6 ).
A 100uf electrolytic capacitor is placed in parallel with the power supply for maximum noise reduction.
NOTE FOR BEGGINERS: IN THE CIRCUIT SYMBOL OF AN ELECTROLYTIC CAP, THE STRAIGHT LINE IS THE POSITIVE TERMINAL AND THE CURVED ONE IS THE NEGATIVE TERMINAL.
ANOTHER NOTE: THE GAIN OF THE AMPLIFIER CAN BE INCREASED BY CONNECTING A 10uf ELECTROLYTIC CAP TO PIN 1 AND 8 OF THE IC. +ve TERMINAL OF CAP TO PIN 1 and -ve TO PIN 8, A 10K POT CAN BE PLACED IN SERIES BETWEEN PIN1 AND THE CAPACITOR's +ve TERMINAL.
Step 6: FIRE HER UP!
I am using 12V 7.0A power supply, but even a simple 9V cell will do the job efficiently .
BUT REMEMBER : MORE VOLTAGE = HIGHER OUTPUTS
For the speaker, as mentioned earlier i have used a 3 Ohm 10 watt speaker which served as the center speaker of my home theater setup.
IF you don't have access to FRSs, use MID RANGE SPEAKERS for good performance levels.
Using a tweeter will only reproduce the high frequencies and it wouldn't really serve the purpose of the amplifier.
Step 7: THE END
NOTE : I kinda modified the components layout and switched the power source to a 9V cell. This was done to take better pictures.
Feel free to ask questions and stay tuned for the upgraded versions!
All suggestions are appreciated :D