The telephone is one of the most creative and prized inventions in the world. It has advanced from its humble beginnings to its wireless communication technology today and for the future. The inhabitants of the earth have long communicated over a distance, which has been done by shouting from one hilltop or tower to another. The word "telephone" originated from a combination of two Greek words: "tele", meaning far off, and "phone", meaning voice or sound, and became the known term for "far- speaking."
A basic telephone usually contains a transmitter, that transfers the caller's voice, and a receiver, that amplifies sound from an incoming call. In the transmitter there are two common kinds of transmitters: the carbon transmitter, and the electret transmitter. The carbon transmitter uses carbon granules between metal plates called, electrodes, with one consisting of a thin diaphragm that moves by pressure from sound waves and transmits them to the carbon granules. These electrodes conduct electricity flowing through the carbon. The sound waves hit the diaphragm causing the electrical resistance of the carbon to vary. The electret transmitter is composed of a thin disk of metal-coated plastic held above a thicker, hollow metal disk. This plastic disk is electrically charged, and creates an electric field. The sound waves from the caller's voice cause the plastic disk to vibrate, changing the distance between the disks, thus changing the intensity of
the electric field. These variations are translated into an electric current which travels across the telephone lines. The receiver of a telephone is composed of a flat ring of magnetic material. Underneath this magnetic ring is a coil of wire where the electric current flows. Here, the current and magnetic field from the magnet cause a diaphragm between the two to vibrate, and replicate the sounds that are transformed into electricity.
The telephone is also composed of an alerter and a dial. The alerter, usually known as the ringer, alerts a person of a telephone call, created by a special frequency of electricity sent by the telephone number typed in. The dial is the region on the phone where numbers are pushed or dialed. There are two types of dialing systems; the rotary dial, and the Touch-Tone. The rotary dial is a movable circular plate with the numbers one to nine, and zero. The Touch-Tone system uses buttons that are pushed, instead of the rotary that send pulses.
The telephone was said to be invented by many people. However, the first to achieve this success, although by accident, was Alexander Graham Bell. He and his associate were planning to conduct an experiment, when Mr. Bell spilt acid on himself in another room, and his associate clearly heard the first telephone message: "Mr. Watson, come here; I want you." Although Alexander Graham Bell had invented the telephone, his case had to be defended in court more than 600 times for this to be proven.
After the invention of the telephone, many other great technological advances were made, which boosted the telephone into a worldwide affair. The first great advance was the invention of automatic switching. Next, long distance telephone calls were established in small steps. For example, from city to city, across a country, and across
the ocean. Following this, undersea cable and satellites, which made it possible to link points halfway around the earth sounding as if from next door. Finally, by adding three digit area codes, all phone calls, either to next door or around the world, could be done by the caller.
The first telephone company to establish a telephone industry was the Bell Telephone Company, in 1877, by Alexander Graham Bell. This did last for sometime, however, independent telephone companies were started in many cities and small towns. By 1908, many customers were being served by a new company called AT&T, which eventually bought out the Bell Company. Since it was costly to have the wires run to a household, many residential people often shared lines, which is called a party line. Although these lines were cheaper for the customers, it was a nuisance because only one person could use the phone at a time, and other households could listen in on the calls. Finally, the price of local calls was relatively low, however, long-distance calls were placed relatively high when compared to the local telephone bill.
Today, approximately 95% of the households across North America have telephones, which is creating a huge opportunity for companies that provide local and long-distance service. Although prices for calls are slowly decreasing, the competition between companies is increasing. This can be seen from advertisements on television and in the newspaper. And not only is this competing going to continue, it will increase as new technology is discovered.
What is in store for the future? No one will now. However, some of the latest futuristic ideas that will soon be upon us are; television screens soon accompany the telephone, so that the caller can see who he or she is having a conversation with. Also, having all of the copper wire replaced with fiber optics will greatly increase the telephones capabilities. This will give us the advantage of sending very large pieces of information over the phone line. The only thing that we do know about the telephone, is that it sure has come a long way since its first discovery by the inventor Alexander Graham Bell. A man who will always be remembered.
Source: Essay UK - http://www.essay.uk.com/coursework/the-telephone-system.php