26-08-2017, 01:25 PM
The intercom is a useful circuit that keeps you in touch with your relative present in another room without moving from your place. You can mount this circuit in the outside area of your house as in the garage, and you can this circuit for bidirectional communication.
LM386 is a very popular and widely used 8 pin audio amplifier used to amplify sound signals. The circuit described below can also be used to amplify the sound signals from the mobile output, CD player or can be used in cars to amplify the sound signal.
To understand the operation of the circuit first we must understand its pin description-
Pin 1 and pin 8 are used for gain control of the amplifier.
Pin 2 and pin 3 are used to power the input signal that is required to be amplified. The pin 2 is used for the negative input and the pin 3 is for the positive signal.
The pin 4 is used as ground.
Pin 6 is used to connect the DC power supply.
Pin 5 is used as output.
Pin 7 is used as a bypass terminal with a capacitor to prevent oscillation.
The work of this intercom circuit is very simple first we have to adjust its gain factor through bolts 1 and 8 if left open the gain will be 20 as it is internally fixed in IC but can be variable by adding a resistance and A capacitor Up to 200. Now feed the required signals to pin 2 or 3. A resistor is connected to pin 3 to adjust the sensitivity of the input signal and we will get the output on pin 5.
C4 is used as a bank for output means when the current demand becomes low it supplies electrons or when sudden increases in current occur. C5 act as a coupling capacitor that eliminates DC signals and only transmits AC signals through it. And we'll get the amplified signals through the speaker.
The loudspeaker volume can be adjusted with the help of variable resistor VR1.For the circuit to function as two-way intercommunication make two identical circuits as shown in the circuit diagram. Now connect the output of one unit to the speaker of the other unit and vice versa and use the independent power supply for two units and connect them with 3 core wire, two wire for the outputs and a wire for common ground is required for the Intercom connection. You can see from the bottom circuit how to connect the two units simultaneously.
LM386 is a very popular and widely used 8 pin audio amplifier used to amplify sound signals. The circuit described below can also be used to amplify the sound signals from the mobile output, CD player or can be used in cars to amplify the sound signal.
To understand the operation of the circuit first we must understand its pin description-
Pin 1 and pin 8 are used for gain control of the amplifier.
Pin 2 and pin 3 are used to power the input signal that is required to be amplified. The pin 2 is used for the negative input and the pin 3 is for the positive signal.
The pin 4 is used as ground.
Pin 6 is used to connect the DC power supply.
Pin 5 is used as output.
Pin 7 is used as a bypass terminal with a capacitor to prevent oscillation.
The work of this intercom circuit is very simple first we have to adjust its gain factor through bolts 1 and 8 if left open the gain will be 20 as it is internally fixed in IC but can be variable by adding a resistance and A capacitor Up to 200. Now feed the required signals to pin 2 or 3. A resistor is connected to pin 3 to adjust the sensitivity of the input signal and we will get the output on pin 5.
C4 is used as a bank for output means when the current demand becomes low it supplies electrons or when sudden increases in current occur. C5 act as a coupling capacitor that eliminates DC signals and only transmits AC signals through it. And we'll get the amplified signals through the speaker.
The loudspeaker volume can be adjusted with the help of variable resistor VR1.For the circuit to function as two-way intercommunication make two identical circuits as shown in the circuit diagram. Now connect the output of one unit to the speaker of the other unit and vice versa and use the independent power supply for two units and connect them with 3 core wire, two wire for the outputs and a wire for common ground is required for the Intercom connection. You can see from the bottom circuit how to connect the two units simultaneously.