How a Generator Works

A generator is used to turn mechanical energy into electrical energy, just the opposite of a motor. The basics of the generator are pretty basic. It runs on the principle of electromagnetic induction, discovered by Michael Faraday. Once you know what electromagnetic induction is, it is easy to learn how a generator works.

Electromagnetic Induction
Michael Faraday found in 1831, that if a conducting wire or material was moved through a magnetic field, an electrical current would form in the wire. Now on to the generator...

The Generator

 (Picture from KSS. I own no rights to the diagram)

This is a diagram of a wind turbine, but it is very similar to a generator. At the bottom is the turbine, which would be a crank in a real generator. When this is turned, so is the coil of conducting wire that is attached to it. It is moved through the magnetic lines of force created by the permanent magnet. This induces a current in the wire, and in this case it would light the light bulb.

How a Lightbulb Works

In the 1800's, the electric light bulb was invented, the one that illuminates our night. The technology of the basic light bulb has evolved very little from the past. The mechanics of a light bulb are very simple, as long as you understand wire resistance. Let's go into the science of how a light bulb works.

Structure

(Picture from Energy Crysis I own no rights to the diagram.)

There are two small metal rods at the bottom of the bulb, which are connected to the electrical foot contact. Attached to the two rods are two pieces of stiff wire. On top of the wire is something called a filament. This filament is usually made from tungsten, which is a very resistant material. This means that the tungsten has many atoms blocking the path of electrons. When the flow of electrons go through the resistant filament, some of them collide with the atoms. This kicks the electron up to a higher energy level for a fraction of a second. When the electron calms down, it releases a photon of light, which is the light that you see coming from the bulb. The electrons collide all the time, and photons of light are released all the time so that you can have a consistent source of light.

How a CRT Television Works

Billions of people all over the world enjoy television. A few years ago the most common type of TV was the cathode ray tube (CRT) TV. This is where television got its nickname, 'the tube'. Since then, the technology has become more advanced and liquid crystal display (LCD) and plasma TVs have come into play. For now, though, we will be sticking to the CRT TV and how it works.

The Brain
Just like many other things in this world, TV would not be possible without two amazing powers of the brain. The first thing that is required to watch TV is something I call 'dot assembling'. When you see an image, made up of many small dots (in this case, pixels), the brain will assemble those little specks into a clear image.
The second power that the brain has is the ability to put together a series of images, each slightly different than the last, into a moving picture. Both of these powers work together to allow you to watch TV.

The Cathode Ray Tube
The CRT starts with a heated filament, similar to one in a light bulb. A stream of electrons is produced naturally. Next comes the anode, which both focuses and accelerates the stream of electrons. The stream is now aimed directly at the outer screen of the CRT.

Moving the Stream
Inside the TV, behind the CRT, is a pair of electromagnets. These react with the stream to move it sideways and up and down. The stream can be moved to anywhere on the screen.

Making the Picture
To start making the picture, the stream of electrons is moved to the top left corner of the screen. The outer screen of the CRT is coated in phosphor, and when the electrons hit it, the phosphor glows. This is then projected onto the TV screen. The electromagnets move the electrons across the screen, 'painting a picture'. The picture is painted line by lines, 60 times a second. To make the different variations between black, white and gray, the stream of electrons is intensified by increasing the voltage. To make white, the voltage goes on at full blast. To create black, the voltage is turned off when the stream scans by.

Color CRT TV

A color TV is very similar to a black and white TV, structurally. There are just a few differences. There are three electron streams, instead of one. The colors of the streams are red, green and blue. Also, the phosphor coating on the screen is three colors, red, green and blue, arranged in dots or stripes. Lastly, there is a thin sheet of metal that has very small holes in it, aligned with the phosphor dots. Every color is made of some combination of red, green and blue.