Transcript History of the telephone

History of the telephone
the chronicles history of the telephone The
development of electrical technology that
enabled bidirectional human speech
conversations over distances farther than a
person could shout .
Electrical devices
The telephone began as improvements to the
Samuel Thomas von Soemmering telegraph
in 1809. An constructed his
was created by electromagnetic telegraph
Carl Friedrich .in 1832 Baron Schilling
built an Wilhelm Weber and Gauß
electromagnetic telegraph in 1833 in
electrical commercial The first .Göttingen
William was constructed by Sir telegraph
and entered use on the Fothergill Cooke
It .Britain in Great Western Railway
Paddington station ran for 13 miles from
and came into West Drayton to
.1839 ,April 9 operation on
The electrical telegraph owned and built by Samuel F.
B. Morse
An electrical telegraph was independently developed
in 1837 by United States and patented in the
,Alfred Vail ,His assistant .Samuel Morse
with alphabet signaling Morse code developed the
Morse. America's first telegram was sent by Morse
across two miles of wiring. ,1838 ,January 6 on
During the late 19th century inventors tried to find
ways of sending multiple telegraph messages
simultaneously over a single telegraph wire by using
different audio frequencies for each message. These
Thomas ,Charles Bourseul inventors included
.Alexander Graham Bell and ,Elisha Gray ,Edison
to acoustic telegraphy. Their efforts to develop
reduce the cost of telegraph wires led to the
telephone.
Invention of the telephone
Credit for inventing the electric telephone
,Charles Bourseul .remains in dispute
,Johann Philipp Reis ,Antonio Meucci
,Elisha Gray and Alexander Graham Bell
amongst others, have all been credited with
The early history of the .invention the
telephone is a confusing morass of claim and
counterclaim, which was not clarified by the
huge mass of lawsuits which hoped to
resolve the patent claims of individuals. The
Bell and Edison patents, however were
forensically victorious and commercially
decisive.
is often credited as Alexander Graham Bell
the inventor of the telephone, and the
was recognized Antonio Meucci Italian
by US Congress on June 11, 2002 for his
pioneer work on the telephone. However,
the modern telephone is the result of work
done by many people, all worthy of
recognition of their contributions to the
field. Bell was merely the first to patent
the telephone, an "apparatus for
transmitting vocal or other sounds
telegraphically", 16 years after Meucci,
who did not have sufficient funds to file a
patent application, demonstrated his
"teletrofono" in New York in 1860.
Elisha Gray and Alexander Bell The
considers the question controversy
of whether Bell and Gray invented
the telephone independently and, if
not, whether Bell stole the invention
from Gray. This controversy is more
narrow than the broader question of
who deserves credit for inventing the
telephone, for which there are
several claimants.
Early telephone
developments
The following is a brief summary of the history
of the development of the telephone :
at the Graham Bell Copy of the original phone of
in Paris Musée des Arts et Métiers
invented a string telephone Robert Hooke :1667
that conveyed sounds over an extended wire
.by mechanical vibrations
first mooted the Innocenzo Manzetti :1844
.)telephone( ”idea of a “speaking telegraph
writes a memorandum Charles Bourseul :1854
on the principles of the telephone.(See the
article : "Transmission électrique de la
Paris, 26 August ,L'Illustration ,"parole
.)1854
demonstrates an electric Antonio Meucci :1854
voice-operated device in New York; it is not
.clear what kind of device he demonstrated
constructs the first speech- Philipp Reis :1861
transmitting telephone
Western Elisha Gray establishes :1872
.Manufacturing Company Electric
Bell uses a bi-directional :1875 ,July 1
"gallows" telephone that was able to
transmit "voicelike sounds", but not clear
speech. Both the transmitter and the
receiver were identical membrane
.electromagnet instruments
experiments with Thomas Edison :1875
and in November acoustic telegraphy
builds an electro-dynamic receiver, but does
.not exploit it
the ( Tivadar Puskas Hungarian :1875
arrived in )telephone exchange inventor of
the USA
Bell's U.S. Patent 161,739 "Transmitters and Receivers for :1875,April 6
Electric Telegraphs" is granted. This uses multiple vibrating steel reeds in make.break circuits, and the concept of multiplexed frequencies
Elisha Gray designs a liquid transmitter for use with a :1876,February 11
.telephone, but does not build one
.Bell's U.S. patent 174,465 for the telephone is granted :1876 ,March 7
Bell transmits the sentence "Mr. Watson, come here, I want to :1876 ,March 10
.see you" using a liquid transmitter and an electromagnetic receiver
Bell's U.S. patent 186,787 is granted for an electro-magnetic :1877 ,January 30
.telephone using permanent magnets, iron diaphragms, and a call bell
Edison files for a patent on a carbon (graphite) transmitter. The :1877 ,April 27
after a 15-year delay because of ,1892 ,May 3 patent 474,230 was granted
litigation. Edison was granted patent 222,390 for a carbon granules transmitter
.in 1879
First long-distance telephone line :1877
Century
20th developments
By 1904 there were over three million phones in the US
What turned .still connected by manual exchanges
out to be the most popular and longest lasting
physical style of telephone was introduced in the
A .Bell's Model 102 early 20th century, including
and electromagnetic carbon granule transmitter
receiver were united in a single molded plastic handle,
which when not in use sat in a cradle in the base
of the Model 102 shows circuit diagram unit. The
the direct connection of the receiver to the line, while
the transmitter was induction coupled, with energy
supplied by a local battery. The coupling transformer,
battery, and ringer were in a separate enclosure. The
in the base interrupted the line current dial switch
by repeatedly but very briefly disconnecting the line
1-10 times for each digit, and the hook switch (in the
center of the circuit diagram) permanently
disconnected the line and the transmitter battery
while the handset was on the cradle.
After the 1930s, the base also enclosed the bell and induction
coil, obviating the old separate bell box. Power was supplied
to each subscriber line by central office batteries instead of a
local battery, which required periodic service. For the next
half century, the network behind the telephone became
progressively larger and much more efficient, but after the
dial was added the instrument itself changed little until
.touch tone replaced the dial in the 1960s
can be traced back to two-way history of mobile phones The
radios permanently installed in vehicles such as taxicabs,
police cruisers, railroad trains, and the like. Later versions
such as the so-called transportables or "bag phones" were
equipped with a cigarette lighter plug so that they could also
be carried, and thus could be used as either mobile two-way
phones by being patched into the portable radios or as
.telephone network
wRae and Douglas H. Ring ,In December 1947
Bell Labs engineers, proposed ,Young
Philip T. ]2[.hexagonal cells for mobile phones
Porter, also of Bell Labs, proposed that the cell
towers be at the corners of the hexagons rather
than the centers and have directional antennas
that would transmit/receive in 3 directions (see
picture at right) into 3 adjacent hexagon
The technology did not exist then ]4[ ]3[.cells
and the frequencies had not yet been allocated.
Cellular technology was undeveloped until the
Joel S. 1960s, when Richard H. Frenkiel and
.of Bell Labs developed the electronics Engel
Martin Motorola manager 1973 ,April 3 On
placed a cellular phone call (in front of Cooper
reporters) to Dr. Joel S. Engel, head of research
This began the era of .Bell Labs at AT&T's
.the handheld cellular mobile phone
Cable television companies began to use their
fast-developing cable networks, with
ducting under the streets of the United
Kingdom, in the late 1980s, to provide
telephony services in association with
major telephone companies. One of the
Cable ,early cable operators in the UK
connected its first cable ,London
telephone customer in about 1990
21st Century
developments
Internet Protocol (IP) telephony (also known
telephony) is a service based on internet as
disruptive VoIP), a( Voice over IP
that is rapidly gaining ground technology
against traditional telephone network
South Korea and Japan technologies. In
up to 10% of subscribers, as of January
2005, have switched to this digital
telephone service
internet broadband IP telephony uses a
connection to transmit conversations as
In addition to replacing .data packets
IP telephony is also competing ,POTS
with mobile phone networks by offering
WiFi free or lower cost connections via
VoIP is also used on private .hotspots
wireless networks which may or may not
have a connection to the outside telephone
network
By Students :
Noor Al-sheyab .
From : 6th Grade (B) .
Teacher: Lana Fashho