How do you make TVs and VCRs?
Here is a good diagram that can help explain how a TV works. It's from Compton's Interactive Encyclopedia.
The television has two major sections. One is very much like a radio, it receives a picture and sound through an antenna or through your cable or VCR. The signals that are received are converted into a picture.
The device that shows the picture is a big glass tube like a huge light bulb. It's called the picture tube. The original picture tube was quite simple and it's name was the cathode ray tube or CRT.
The picture is actually made by a bright dot that zigzags back and forth, top to bottom on the screen. As the dot moves, it gets brighter or darker depending on the picture. You eye doesn't see just one dot becuase it moves so fast.
Sometime when you watch TV, move your hand quickly in from of your eyes and you may see the effect of this dot causing your hand to look like it's grown a few extra fingers!
Now, about the VCR... There is a great explanation in The Illustrated Encyclopedia of Inventions in the school library. Look it up on page 1829 of volume 20 next time you are there.
Answer #% % filename A142B.DOC page% % page 1 of% % numpages 1 % % date \@ "MMMM d, yyyy"November 18, 1997
€Ali Farhat, room 12, Mrs. MastineBack to