Working and uses of fax machine,cell phone,photo phone and co puter

1. Uses and working of the
following
fax machine
cell phone
photo phone
computer

2. FAX MACHINE

3. Working of a fax machine
•A fax machine (from the word facsimile or
copy) is designed for sending copies of
documents over phone lines to anywhere in
the world. They were in use long before the
introduction of PC's, the development of the
World Wide Web, or the widespread use of
Email. A lot of businesses and individuals still
use them because they are simple, cheap, and
don't require a PC or an internet connection.
•Basically a Fax machines is three devices in
one.

4. •First is a document scanner, usually
monochrome, and usually sheet-feed.The second
is a printout device, also sheet feed with an inkjet
or laser print engine, or roll feed for thermal
paper.Joining them together would be small
dedicated purpose computer and modem.They
look very similar to a home-type inkjet printer. You
put your documents to be sent in one tray, enter
the phone number of the fax machine you wish to
send the documents to and press Send. The
machine draws the documents through it,
scanning them and saving digital images into
memory. The machine dials the number, waits for
acknowledgment from the fax machine on the
other end then transfers the images using
different frequency tones to translate varying
shades of dark and light.

6. Uses of fax machine
•A fax machine is used to send documents instantly to
another fax machine through a standard telephone line.
Most fax machines can also be used to make copies of
documents and some can also be used as a computer
printer or scanner.
•A fax machine can send and receive documents that
include text and images simply at the push of a button.
The advantage of a fax machine over an email is that it
takes a physical document from the sender and transmits
it in physical form to the receiver.
•There is no need to scan the document before sending it,
nor do you have to print it off when you receive it - both of
which you would have to do with e-mail. This is because
the fax machine basically is a scanner, modem and
printer all in one unit, which cuts down on your need for
all of these machines.

7. Cell phone

8. CELL PHONE
•Millions of people in the United States and around
the world use cellular phones. They are such great
gadgets -- with a cell phone, you can talk to anyone
on the planet from just about anywhere!
•These days, cell phones provide an incredible array
of functions, and new ones are being added at a
breakneck pace. Depending on the cell-phone
model, you can:
•Store contact information
•Make task or to-do lists
•Keep track of appointments and set reminders

9. •Use the built-in calculator for simple math
•Send or receive e-mail
•Get information (news, entertainment,
stock quotes) from the Internet
•Play games
•Watch TV
•Integrate other devices such as PDAs,
MP3 players and GPS receivers

10. But have you ever wondered
how a cell phone works?
•To start with, one of the most interesting things
about a cell phone is that it is actually a radio -- an
extremely sophisticated radio, but a radio
nonetheless. The telephone was invented by
Alexander Graham Bell in 1876, and wireless
communication can trace its roots to the invention of
the radio by Nikolai Tesla in the 1880s (formally
presented in 1894 by a young Italian named
Guglielmo Marconi). It was only natural that these
two great technologies would eventually be
combined.

11. •When a mobile phone is switched on, it finds and
connects to a nearby mobile phone base station.
Computers in the base station check that the
phone is allowed to use the network. The base
station covers what is called a cell and a phone
can move between different cells, but will only ever
communicate with one cell at a time. This is why
mobile communications are sometimes called
cellular communications.Once connected to a cell,
the mobile phone can make calls. Because the
network knows that the phone is connected to that
particular cell, it can also route calls to the mobile
phone. Sometimes the radio connection to the cell
is lost, for example when you go underground. This
means the phone cannot make or receive calls
until the connection is made again.

12. PHOTO PHONE
•On June 3, 1880, Alexander Graham Bell transmitted the
first wireless telephone message on his newly invented
"photophone." Bell believed the photophone was his most
important invention. The device allowed for the transmission
of sound on a beam of light. Of the eighteen patents granted
in Bell's name alone, and the twelve he shared with his
collaborators, four were for the photophone.
•Bell's photophone worked by projecting voice through an
instrument toward a mirror. Vibrations in the voice caused
similar vibrations in the mirror. Bell directed sunlight into the
mirror, which captured and projected the mirror's vibrations.
The vibrations were transformed back into sound at the
receiving end of the projection. The photophone functioned
similarly to the telephone, except the photophone used light
as a means of projecting the information, while the telephone
relied on electricity.

13. •Although the photophone was an extremely
important invention, it was many years before the
significance of Bell's work was fully recognized. Bell's
original photophone failed to protect transmissions
from outside interferences, such as clouds, that
easily disrupted transport. Until the development of
modern fiber optics, technology for the secure
transport of light inhibited use of Bell's invention.
Bell's photophone is recognized as the progenitor of
the modern fiber optics that today transport over
eight percent of the world's telecommunications.

14. COMPUTER
•To accomplish a task using a computer, you need a
combination of hardware, software, and input.
•Hardware consists of devices, like the computer itself, the
monitor, keyboard, printer, mouse and speakers. Inside your
computer there are more bits of hardware, including the
motherboard, where you would find the main processing
chips that make up the central processing unit (CPU). The
hardware processes the commands it receives from the
software, and performs tasks or calculations.
•Software is the name given to the programs that you install
on the computer to perform certain types of activities. There
is operating system software, such as the Apple OS for a
Macintosh, or Windows 95 or Windows 98 for a PC. There is
also application software, like the games we play or the tools
we use to compose letters or do math problems.
•You provide the input. When you type a command or click on
an icon, you are telling the computer what to do. That is
called input.

15. How They Work Together
•First, you provide input when you turn on the computer. Then
the system software tells the CPU to start up certain
programs and to turn on some hardware devices so that they
are ready for more input from you. This whole process is
called booting up.
•The next step happens when you choose a program you want
to use. You click on the icon or enter a command to start the
program. Let's use the example of an Internet browser. Once
the program has started, it is ready for your instructions. You
either enter an address (called a URL, which stands for
Uniform Resource Locator), or click on an address you've
saved already. In either case, the computer now knows what
you want it to do. The browser software then goes out to find
that address, starting up other hardware devices, such as a
modem, when it needs them.

16. •If it is able to find the correct address, the
browser will then tell your computer to send the
information from the web page over the phone
wire or cable to your computer. Eventually, you
see the web site you were looking for.If you
decide you want to print the page, you click on
the printer icon. Again, you have provided input to
tell the computer what to do. The browser
software determines whether you have a printer
attached to your computer, and whether it is
turned on. It may remind you to turn on the
printer, then send the information about the web
page from your computer over the cable to the
printer, where it is printed out.