Amazing Technology

There are certain thing we use often now a days that we take for granted. Cell phones for example...how the hell do they work. One thing that always blew my mind was the fax machine.


Think about it. I'm in New York. I put a piece of paper in this machine, and in 1 minute, the exact same copy comes out of a different machine in California. The crazy thing is, that piece of paper somehow gets coded into something that goes through a phone line. WTF. How????

Fax machines, in short, digitize an image by converting it into a crazy series of dots, which then are converted to electrical impulses which can be sent through a phone line. To send a fax, a piece of paper is attached to a rotating drum, with the print facing outward. A small photo sensor containing a lens and a light, was attached to an arm that faced the sheet of paper. The arm moved downward over the sheet of paper from one end to the other as the sheet rotated on the drum. The photo sensor focused on a very small spot, which was either black or white, on the paper. The drum rotated, allowing the photo sensor to examine one line of paper at a time.

Ok so now, this information gets sent through a telephone line, using tones. If the spot of paper that the photo was looking white, a certain tone would be sent. If it was black, a different tone would be sent. These tones were actually different frequencies on the phone line – 800 Hertz for white and 1,300 Hertz for black. At the receiving end, there would be a similar rotating drum, with a "pen" to mark on the paper. When the receiving fax machine heard a 1,300-Hertz tone, it would apply the pen to the paper. When it heard an 800-Hertz tone, it would take the pen off the paper...thus producing the copy of your paper.

Pretty wild huh. Now you know how these babies work, and as they say, knowing is half the battle.

Fax machines, It's Kinda Like...-C-