TELEGRAPH - PowerPoint PPT Presentation

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TELEGRAPH

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telegraph & telephone – PowerPoint PPT presentation

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Title: TELEGRAPH


1
TELEGRAPH TELEPHONE
2
Outline
  • Visual Telegraphy
  • Electric Telegraphy
  • Telegraph Lines
  • Telephone

3
Visual Telegraphy
  • Claude Chappe (1763-1805)
  • Built By Abraham Bruguet (1793)
  • Clockmaker
  • Could Have Been Built Earlier (100 Years)
  • Lacked Telescope
  • Stations Too Close
  • First Stations
  • Menilmontant
  • Saint-Martin-du-Tertre (21 Miles Away
  • First Line
  • Paris to Lille

4
Chappe Semaphore System
  • Masonry Towers
  • Wooden T
  • Horizontal Beam (Regulator)
  • Pivoted On Axis
  • Jointed Arms (Indicator)
  • Pivoted On Regulator Ends
  • Cranks Ropes
  • 196 Different Positions
  • Chappe Code - 92 Positions
  • Diplomatic Dictionary
  • 92 Pages - First Signal
  • 92 Words Per Page - Second Signal
  • Second Dictionary - Phrases

5
Chappe Semaphore System
  • Slowed Development Of Electric Telegraph
  • France
  • Nothing New Technologically
  • Increased Communication
  • Calais To Paris
  • 33 Posts, 58 Leagues, 3 Minutes
  • Toulon To Paris
  • 10 Posts, 200 Leagues, 20 Minutes
  • Used Extensively In WW I
  • Still Used - Aircraft Carriers

6
Electric Telegraphy
  • Electric Battery
  • Electromagnetism
  • First Electric Telegraphs
  • Relays
  • Alphabetical Devices
  • First French Telegraphic Devices
  • Printing Devices
  • Morse System
  • Telegraph Lines
  • Machinery Electrical Industry

7
Electric Battery
  • Telegraph - Electric Current
  • Continuous
  • Permanent
  • Voltaic Pile - Not Satisfactory
  • Cesar Bequerel (1828)
  • Two-Fluid Class
  • J.F. Daniell (1836)
  • Daniell Cell
  • Reliable
  • Contiuous

8
Electromagnetism
  • Conductor Traversed By Electric Current
  • Magnetic Needle Moves
  • Georges-Louis Lesage (1774)
  • Dischages Of Static Electricity From Leydon Jar
  • 24 Wires For Alphabet
  • Underground - Conductors Insulated By Glass
  • Ampere (1820)
  • Deviation Of Magnetic Needle

9
Electromagnetism (Continued)
  • Baron Schilling (1832)
  • Six Indicators Six Wires
  • Black Side White Side
  • Two Additional Wires
  • Call Signs
  • Return Current
  • Carl-August von Steinheil
  • Single Circuit (1827)
  • Return Current Through Ground (1828)

10
First Electric Telegraphs
  • Euston Camden In London (1837)
  • 40 Years After Chappe
  • 1 Mile Long
  • Sir William F. Cooke (1806-1879)
  • Sir Charles Wheatstone (1802-1875)
  • Five Needles Circuits With Six Wires
  • Wheatstone Clarke (1842)
  • Two Needle Instrument
  • Alexander Bain (1843)
  • Single Needle Instrument

11
Five Needle Telegraph By W C
  • Wheatstone Cooke (1837)
  • Top
  • Receiver
  • Bottom
  • Transmitter

12
Local Circuit Of W C Telegraph
  • Left - Relay
  • Right - Calling Device

13
Transmitting-Receiving Post
  • Built By Wheatstone Clarke (1842)
  • Two Needle Instrument
  • Right
  • Transmitters Connections
  • Left
  • General View

14
First Electric Telegraphs
  • Electromagnet (1820s)
  • Ampere Arago
  • Coarse Wires With Few Coils
  • Inappropriate For Operation Over Long Distances
  • Took 20 Years To Be Adopted In Telegraph
  • Telegraphic Devices
  • Alphabetical Telegraph
  • Electric Telegraph With Chappe Signals
  • Morse System

15
Relays
  • Wheatstone (1837)
  • Electrochemical
  • Close Circuit From A Distance
  • U Shaped Tube
  • Acidulated Water Mercury
  • Current Causes Hydrogen To Be Liberated
  • Pressure Cause Mercury To Close Circuit Of
    Sounding Device

16
Relays
  • Wheatstone (1839)
  • Close Circuit From A Distance
  • Needle In Center Of Frame
  • Fork Shaped Contact At One End
  • Current Caused Fork To Plunge Into Containers Of
    Mercury
  • Closed Local Circuit

17
Alphabetical Devices
  • Wheatstone Cooke
  • Clock Movement At Each Post
  • Pointer Turned In Jerks
  • Many Variations
  • Replaced Needle Devices

18
First French Telegraphic Devices
  • Louis Breguet (1844)
  • Same Concept As Wheatstone
  • 2 Needles - Chappe System
  • Escapement
  • Right - Transmitter
  • Left - Receiver

19
First French Telegraphic Devices
  • Keyboard Sender
  • Gustave Froment (1845)
  • Replaced Crank Sender Of Breguets

20
Printing Devices
  • Wheatstone
  • Replaced Dial And Pointer On Alphabetical
  • 24 Radiating Arms With Letter Engraved
  • Hammer Presses On Recording Cylinder
  • Separate Control Circuit
  • John W. Brett (1805-1863)
  • Modified Keyboard Idea Of Froment

21
Printing Devices
  • David E. Hughes (1831-1900)
  • Best Idea
  • Synchonized
  • Transmitter
  • Receiver

22
Morse System
  • Samuel F. B. Morse (1791-1872)
  • Painter Turned Physicist Mechanic
  • Modern Day da Vinci
  • Numerous Biographies
  • Electromagnet With An Armature Holding A Stylus
  • Left Long Short Marks On Paper As It Unrolled
  • Tried Ink Pencil
  • Decided On Rod That Embossed Paper
  • Lacked Experience In Making Electromagnets
  • Studied Works Of Joseph Henry (1797-1878)
  • First Electromagnet Was 2 High

23
Morse System
  • Simplicity
  • Make Signal With A Simple Mechanical Device
  • Similar Movements
  • Transmitter
  • Receiver
  • Single Code With 2 Elements
  • Short Long Signals
  • Combinations Of 4 Signals
  • Every Letter Of Alphabet
  • 12 22 32 42 2 4 9 16 31
  • Similarities Symmetry

24
Morse System
  • Manual Transmitter
  • Right - Flexible Blade (First Model)
  • Left - Jointed Lever Type With Reversing Spring

25
Morse System
  • Perfected Morse System (1845)
  • Diagram Of Connections
  • Baltimore To Washington (1845)
  • Adopted Throughout Europe (Beginning 1846)
  • International Communication (1854)

26
Telegraph Lines
  • Success Of Telegraph Depended On
  • Transmitting Receiving Devices
  • Batteries
  • Transmission Lines
  • First Lines
  • Iron Wires - Poor Results
  • Copper Wires - Tempted Thieves
  • Underground
  • Covered With Cotton Pitch
  • Insulating Wires In Suspension

27
Telegraph Lines
  • Ring Insulator (1845)
  • Insulator With Tension Devices (1845)
  • Porcelein Insulator (1860)

28
Machinery Electrical Industry
  • Telegraph Produced Numerous Inventions
  • Lightning Rods
  • Cummutators, Relays, Sound Devices,
    Galvanometers, Measuring Instruments
  • Telephone
  • New Occupations
  • Physicists To Electrical Engineering
  • First High Tech Occupation In The West

29
Machinery Electrical Industry
  • Pixii (1832)
  • Magnetoelectric Motor
  • Froment (1844)
  • Electric Generators
  • Shown - Froment
  • 8 Soft Iron Hubs
  • 4 Elctromagnets
  • Adapted (1855)
  • Power Clocks In Telegraph Machines

30
Telephone
  • Robert Hooke (1635-1703)
  • Tis not impossible to hear a whisper a furlongs
    distance, it having already been done and
    perhaps the nature of the thing would not make it
    more impossible though that furlong should be ten
    times multiplied
  • J. Philipp Reis (1834-1874)
  • First Practical Electric Telephone (1861)
  • Just A Toy

31
Telephone
  • 1876
  • Alexander Graham Bell - Awarded Patent
  • Based On Hermann Helmholtzs Work
  • Elisha Gray - Superior Design
  • Alexander Graham Bell
  • Teacher Of Deaf
  • Used No External Power Source
  • Still Can Be Used For Short Distances
  • Transmitter Receiver Nearly Identical
  • Electromagnetic Microphone
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