Transistors. How do they work.?

Answer 1

There are many different types of transistors, and entire books dedicated to this subject.

In the simplest possible terms, a transistor is an electron valve. Bipolar transistors have three pins labeled emitter, base, and collector. A small amount of current flowing into the base, can allow a large amount of current to flow from the emitter to the collector.

Field Effect Transistors have a gate pin rather than a base pin, and the conductivity of the transistor is controlled by placing a voltage on the gate pin.

Answer 2

Back in the 1950's, some guys at Bell Labs looked at the diode and said, "Here we have a component that has high resistance for one current direction, and low resistance in the other direction. Can we make a device with VARIABLE resistance?"

They worked on this device, and finally came up with a solution. This device would change the resistance between two of its connections, depending on the current flowing into a third connection. The resistance was exactly proportional to the input current, and when two functions are exactly proportional, mathematically the second function is a "transformation" of the first function. It can be said that the device "transformed" input current into output resistance.

They looked at it and said, "What will we call this thing?" They thought that they should name it after what it did, but "Input transforming-resistor-output-device" was too long. They originally called it a "Transforming Resistor," but this was also too long. They shortened it even further, so "Transforming Resistor" became "Trans-istor."

THAT'S why they call the thing a transistor, because THAT'S WHAT IT DOES. It is simply a resistor, whose value (from emitter to collector) depends on an input current (from base to collector).

A one-transistor amplifier is simply a voltage divider with the transistor as the "bottom" resistor, with in input signal fed into the base.

Answer 3

A transistor in general used in two different ways. 1) as a amplifier 2) act as a switch.

For simple analog circuitry, they can use it for both the amplifier and a switch.

For the digital world, they are used as a switch. It is the basic elements of the micro-chips we are using today. Each transistor is acting as 1 bit. By turning the bit on and off, you will have an symbol of one and zero.

For the actual functionality of the transistor, I would recommend you do a search on the web. There is much information for you to learn.

Good luck!

Answer 4

wikipedia link:
http://en.wikipedia.org/wiki/Transistor

a diode allows current to flow in one direction. a transistor is basically two diodes put in opposing directions. the voltage on the two terminals can be used to control the current at the junction where the two diodes meet.

this is an oversimplification ofcourse

Answer 5

Here is a comparison for you. Picture a river, very wide and very strong with a little stream that feeds into it. If you put a little red dye into the stream, the river picks it up, and rushes it downstream, amplifying either its width (voltage) or speed (current). That's pretty much it, in layman's terms.

Answer 6

Kindy like a three legged switch. The base turns the switch "on" for current to flow between the collector and the emitter,got that? :-)=

Answer 7

Well, got tiny people inside. Sshh..

Answer 8

go to the library