Transistors

[dmc]

Hello guys,

Over the past couple of days Ive been trying to learn about how stuff like radio electronics and amplifiers work. And I get just about everything except transistors. But I think Im just over thinking it, I will explain how I think it works and maybe yall can help me to see if I got it.

Lets say we have a NPN transistor, and i know this wouldnt hapen but to make it simple we have a microphone hooked directly to the base and emitter. And on the base and collecter we have a speaker and a 9volt battery. Now I know there will be other resistors in this but I will leave these out to make it more simple. Basically what im seeing that this transistor is doing is just transfering signal from one circuit to the other(from low Volt to high Volt)
When the microphone has any input into it, it changes the voltage on its circuit therefore affecting the transistor and changing the transistors resistance, which in turn changes the speaker circuits voltage.

SOO if we have the microphone at a steady hertz of 60. It is gonna change the voltage 60 times per second on its circuit therefore changing the speakers circuit voltage 60 times a second. Making the speaker vibrate at 60Hz

Basically the transistor doesnt amplify at all, it just transfers signal. Now I know this might be kind of hard to understand but bare with me please, I am just learning.

Now for all you brave souls that have read through that and understand fully how transistors work. Is this basically how they work? lol

 

[NukeET]

Yes, they DO amplify the signal...especially in the configuration you described. Small changes in current flow in the base-emitter path causes large changes in the collector-base current flow. If I'm not too rusty on transistor theory, your configuration has the greatest gain between input and output.

:tiphat:

 

[Artlav]

Yes, signal transfer is essentially what it does.
You can think of a transistor as a valve - a tiny control signal opens and closes it, thus making the big stream going through the valve to have the same pattern.

Also, here is a nice circuit sim for you:
http://www.falstad.com/circuit/index.html

 

[n72.75]

Does this help:

 

[Keatah]

This is a really great site right here. Basic electronics tutorials in the car audio field -- http://www.bcae1.com/ -- You gotta love the tutorials, they are consistent with good explanations. 77 & 78 show something on transistors.

This is a fine book -- http://www.forrestmims.org/publications.html -- http://www.amazon.com/Getting-Start...3282/ref=sr_1_2?ie=UTF8&qid=1315135408&sr=8-2

And there is this -- http://www.electronics-tutorials.ws/ -- and some kick ass lectures --

-- and -- [ame="http://www.youtube.com/watch?v=-td7YT-Pums"]MAKE presents: The Transistor - YouTube[/ame]

 

[dmc]

Ok thanks everyone. Yea sometimes I overthink things and just need to step back and look at them simpler. And i will definitely play with the simulator and look at the tutorials.