In my previous post, I have already discussed on the pin configuration of the ic lm386,
Today I am going to discuss on a simple application of
this chip, “simple audio amplifier”
What is an audio amplifier?
Audio amplifier is such a device which takes input
signal of lower amplitude, and gives a amplified output whose amplitude may be
several hundred times greater than output given,
In this project I am giving the input signal from my
mobile phone’s 3.5mm head phone jack,
How to take audio signal from phone’s head phone port?
Do you have any old headphone? Just cut it, you will
get 3 or 4 wires there, try to connect them alternatively with a small
speakers, for those two wires The speaker sounds , take those two wires,
Components required-
1.one lm 386 ic chip
2.capacitor 10 micro farad, 220 micro farad,0.1micro
farad
3.resistor 10k
4. 8 ohm speaker
Circuit diagram- 200 gain |
| simplest audio amplifier |
How the circuits works?
The audio signal is applied though the pin 2 and 3,
Between two gain terminal 1 and 8 a capacitor is
added, e pin 7 is connected to ground, It works as by-pass, the amplified output
is take from the pin 5 and ground.
the circuit i have made
proteus diagram-
Similar models-
“cell phone radiation detector”
Here everything is almost same with the basic audio
amplifier, the modifications are
1. Make
a simple coil with any type of wire, connect it’s two terminal with pin 3 and
pin 2,
2. Connect a led instead of the speaker,
How it works?
The little power of the phone signal, induces the coil, the current for
the induction acts as input signal, when somebody calls to the mobile placed
beside the circuit,the led blinks,
Diagram-
The circuit made by me-
the real animation
Thank
u for reading, don’t forget to give your valuable comment.
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