بحث عن الهاتف و تطوراته بالانجليزية

Introduction

Today, we are all familiar with the Telephone as a means of communicating with one another. But, it was only about 125 years ago that the telephone was invented.
The name comes from two words,- tele, meaning 'at a distance' and 'phonic' referring to 'sound'. A telephone is a device that enables us to hear sound at a distance . It is a means of communication everywhere in the world and an ever-expanding sector.
That was 125 years ago and a very different world than today! The electric light was barely used and cars hadn’t been invented ! People wrote letters to communicate with others . Letters took days or weeks to arrive depending on how far they had to travel.

1876 ​​Alexander Graham Bell invented the telephone:
The history of phone began on March 10, 1876. Alexander Graham Bell filed a patent for the invention of the telephone. An invention that will revolutioned the world.
Graham Bell presented his invention in a new form devised by Professor Pierce: "The Hand Telephone." , The magnetic phone Bell consists of a transmitter, a receiver and a single wire. The transmitter (microphone) and receiver (listener) operate on the same principle. Each having a thin diaphragm made of fabric and metal, and a permanent magnet horseshoe, surrounded by a wire winding, thus constituting an induction coil. By hitting the diaphragm, the sound waves vibrate in the field of the magnet. These vibrations generated in the coil when an electrical current proportional to the oscillations of the diaphragm. The current is propagated along a cable to the receiving station, where it modifies the intensity of the magnetic field of the earpiece. These intensity variations in turn cause the vibration of the diaphragm, reproducing the original sound.
but the problem with this phone is you could not do communication with someone far away.

the phone Milde :

Manual of the phone Milde
- Press 3 or 4 times on the call button and wait for the bell.
- Unhook the two receivers, apply them ears to hear the operator.
- Tell the operator the name and address of the caller and wait for it to establish communication.
Speak very close to the unit.
the phone Marty:
Marty the 1910 are the first devices in the network of state incorporating a magnetic appeal (magneto). they are also the first replying to a precise specification, and are thus produced in large series by pluisieure companies; model manufactured by the association of workers in precision instruments AOIP is by far the most common.
it is a local and betterie exists in mobile or wall it is sometimes associated with a wooden endow a safe supply batteries for the microphone because of its peculiar shape reminiscent of a kitchen cabinet he was nicknamed the box a salt. The crank on the side can call the operator.
Above, is the handset, comprising a receiver to listen and a speech microphone.

In the 1920s, appears the dial phone:


The dial is composed of a rotating disc which are carried around the numbers 1 to 9 and then 0. The dialing is done by moving the disk to a stop, since the position in front of which the desired number appears, rotating disk with finger in the direction of clockwise.
Arrived on the stop of metal, the finger is removed and then the disc rotates in the opposite direction to return to its rest position by a spring, by sending the number of pulses corresponding to the number (0 being created by 10 pulses).
Each digit of the dial also has alpha values
1 2 3 4 5 6 7 8 9 0
abc def ghi jkl mn prs tuv wxy oq
They allowed the code to match the telephone exchange in the Paris region (first 3 letters of the name) the corresponding figure (example: 225 for Balzac, for 027 Observatory, 700 for rocket).
In the 1940s, appears the dial phone bakelite:
it is a dial phone made by a very hard plastic is the Bakelite this phone works with the same system as that are invented in 1920 ,but the difference between them is the phone that made by bakelite is more resistant than the first .

But the problem remains that we can not make calls when we want and we can not move the phone with us ...
In the 1980s, appear touch-tone telephones, of all colors and all forms .the first touch-tone phone has 10 buttons. Shortly after the star and hash keys will be added. The phone will now have 12 keys.
but the problem with all these phones we can not take the phone with us and communicate anywhere, so in 1950 man invented a new system of telephone is the cell phone.

1950, cell phones appear:
In 1950, we began to move conversations between various points on the network through the waves, using the terrestrial network or communications satellites.
This technology (and especially the miniaturization of transceivers of electromagnetic waves) gives rise to the mobile phone that makes calls and be reached anywhere in the world. The mobile phone with only a relatively small emitter, it needs to function to be quite close to a relay. To cover a given territory, it is necessary to install a large number of relays.
The evolution of telecommunications technology seems to move towards some convergence: mobile "home" have already freed the wire (they are "wireless" around their base, they should quickly join the phones "to the street, "the mobile). Thus, inside and out, we would phone with a single small device, more staff, free of wire or of any base.
Meanwhile, today's phones can do more than carry voice, increasingly, they will already incorporate or integrate new services: e-mail, GPS navigation system, send and receive images, photographs, data , of radio or television, etc.
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CONCLUSION
thanks to technology man has developed a small idea with simple things in to a very important invention in life. this invention is telephone that allows us to easily communicate with people and we should not travel or wait for days and weeks to know about their and thanks to him the world has become a small village .