How Does Each Component Function in a Transistor Intercom Circuit?

[Taher Habib]

Attached with this post is a picture of an intercom circuit using only transistors. It is a two-staged coupled amplifier circuit. I have constructed this circuit for my college physics project. But for the report I want to know the functionality of every component of the circuit. I would be really grateful if someone could help me with this. Thank You!

 

[Windadct]

C'mon Taher - you can do better then that... what do you know already.

 

[Taher Habib]

I've already constructed the PCB of the circuit. And now all I've got to do is to write a report where I must mention the functioning of every component. I'm not so good in electronics. :(

 

[jim hardy]

From the pinned thread just above, titled "Do Not Post Homework or Coursework Questions Here in the EE Forum"

Before posting anything, please review the Physics Forums Global Guidelines.

If you are seeking help with a homework/coursework/textbook related issue please post your problem in the appropriate forum in our Homework & Coursework Questions area.

Just a heads up, we prefer that you make a solid effort at completing your problem before seeking help. We, as a general rule, will not do your homework for you.

Is it acceptable in some circles to get classroom credit for intellectual work one hasn't done? That's a surefire way to build incompetence and serves nobody's interest.

Start at the beginning:

What is the function of R1?
How does the microphone work? (hint - it's probably an electret )

 

[Taher Habib]

The 0.1μf capacitor is used to couple the input signal with the base of the Q1 transistor. I don't know why R1 is used.

 

[Taher Habib]

And the mic converts the sound signals into electrical signals to feed to the amplifier circuit.

 

[Taher Habib]

I don't understand why the particular values of the components are used

 

[Averagesupernova]

The thought that comes to my mind is why was this project picked? You said yourself:

I'm not so good in electronics. :(

-
Surely there was something else you could have picked.

 

[jim hardy]

I don't know why R1 is used.

take a look at the image on right side of this page.

http://en.wikipedia.org/wiki/Electret_microphone

Learning starts with small steps.
As one progresses his stride lengthens.