Presentation on theme: "Changes in telecommunication By Sophie. Telephone facts The telephone was invented by Alexander Graham Bell. The telephone was invented in the 1876. Another."— Presentation transcript:
Telephone facts The telephone was invented by Alexander Graham Bell. The telephone was invented in the 1876. Another inventor called Elisha Gray also designed a telephone, they both entered a famous battle over the invention of the telephone, which Alexander won. Telephone is the Greek word for far sound.
The first telephone The first telephone didnt have a bell, so the caller had to tap the phone with a hammer to let the receiver know a call was being sent to them. Later on a man called Thomas Watson, invented the bell. In the 1880s, there was a measles epidemic. The doctors were worried that if all the operators(people that plugged a cord that was connected to the persons telephone in to a switch board which would connect them to the person they were calling) got the measles, then nobody would be able to control the telephone operating system. A doctor suggested that rather than relying on operators memories, each person should be assigned a number. This is how we got telephone numbers. Mr. Bells telephones were so popular that he made a company called The Bell telephone company. By 1881, there were 132,700 Bell telephones in homes.
Pushbutton telephone The push button telephone was invented in 1941. Then a transmitter was invented by Walter Hauser Britain in 1947 to amplify (louder) the sound across the wires. This meant calls could be sent longer distances. The first active satellite for telephones was launched in 1962. It was called Echo, and orbited the earth once every 157 hours. This was very important because telephone calls could now be made across oceans without relying on under-sea cables which broke frequently and were sometimes eaten by sharks!
Cordless telephone The cordless phone was invented by a lady called Teri Pall in 1965. She was a Jazz singer be fore she invented the cordless phone. Cordless phones came into stores during 1980. The earliest cordless phones had certain problems. They faced some of the problems such as limited range, poor sound quality and noisy. Poor security is another problem they faced as people could easily listen to there neighbours conversations.
Cell phones A man called Martin Cooper invented the cell phone(also called a mobile phone) in 1973. He was also the first person to talk on a cell phone. When cell phones were first invented, they were the size of a brick. An estimated 250 to 300 million are being used in the U.S. Cell phones contain special metals e.g. Gold and silver. The average U.S cell phone owner only uses their current cell phone for 12 to 18 months.
Bibliography http://inventors.about.com/od/bstartinventors/a/telephone.htm http://library.thinkquest.org/04oct/00451/telephone.htm Google images http://inventors.about.com/od/bstartinventors/a/telephone_3.htm http://ezinearticles.com/?History-of-Cordless-Phones&id=408046 http://www.needbattery.com/Articles/History-of-Cordless- Phones.html http://wiki.answers.com/Q/Who_invented_the_cell_phone_and_w hen http://wanttoknowit.com/when-was-the-cell-phone-invented/ http://www.earthday.gatech.edu/Cell%20Phone%20FACTS.pdf