Electronics/History/Chapter 3

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Golden Age: 1875-1917

In 1885, William Stanley, Jr. built the first practical induction coil based on Lucien Gaulard and Josiah Willard Gibbs' idea. It was the precursor of the modern transformer.


War of Currents[edit]

From Wikipedia, the free encyclopedia.

Topics related to Nikola Tesla Tesla, SI unit Tesla patents Wardenclyffe Tower War of Currents Egg of Columbus Tesla coil Tesla turbine Teleforce

In the "War of Currents" era in the late 1880s, Nikola Tesla and Thomas Edison became adversaries due to Edison's promotion of direct current for electric power distribution over the more efficient alternating current advocated by Tesla.

During the initial years of electricity distribution, Edison's direct current was the standard for the United States and Edison was not disposed to lose all his patent royalties. From his work with rotary magnetic fields, Tesla devised the system for transmission of power over long distances. He partnered with George Westinghouse to commercialize this system. Westinghouse had previously bought the rights to Tesla's polyphase patents and other patents for AC transformers.

The direct current electric power transmission system had many limitations that were recognized and solved by Tesla's alternating current. High currents of direct current melted copper wires and could rarely be transmitted for a distance of greater than a mile. Edison's response to this argument was to generate power near to where it is consumed and install more wires to handle the growing demand for electricity but this solution proved to be impractical and unmanageable. However, the single strongest argument against the DC system was that because it maintained a constant voltage, it could not be stepped up or down with a simple transformer. This meant that separate electrical lines had to be installed in order to supply power to appliances that use different voltages, which led to an even greater number of wires to lay and maintain, wasting money and introducing unnecessary hazard. A number of deaths from the Great Blizzard of '88 are attributed to collapsing DC power lines that cluttered cities running DC power grids.

When Tesla introduced alternating current after filing seven patents for alternating current generators, transformers, motors, wires and lights in November and December of 1887, it became clear that AC was the future of electric power distribution. Distance ceased to be a problem and high-voltage AC could carry the same amount of power that would normally melt wires using direct current. Most importantly, alternating current could be easily manipulated with a transformer to change voltage and current. A lamp needing five volts could draw power from the same source as a machine using twenty volts, unlike with the DC system. High voltage alternating current was sent from source to destination without melting wires and then stepped down to low voltages in homes and factories for local use.


Tesla's US390721 Patent for a "Dynamo Electric Machine" Larger version

The advantage of AC for distributing power over a distance is due to the fact that power is given by voltage x current (P = VI). For a given power, a low voltage requires a higher current and a higher voltage requires a lower current. However, since metal conducting wires have a certain resistance, some power will be wasted as heat in the wires. This power is given by P = I2R, or by P = V2/R (here the V in question is the voltage DROP along the wire, not the overall voltage). Clearly it can be seen that low voltage, high current transmissions will suffer a much greater power loss than a high-voltage, low current supply, even though the overall transmitted power is the same. In this respect, whether DC or AC is used is irrelevant. However, it is very difficult to transform DC power to a high voltage, low current form efficiently, whereas with AC this is a matter of a simple and very efficient transformer. This is the key to the success of the AC system.

Experts announced proposals to harness the Niagara Falls for generating electricity. Against General Electric and Edison's proposal, Tesla's AC system won the international Niagara Falls Commission contract. The commission was led by Lord Kelvin and backed by entrepreneurs such as J. P. Morgan, Lord Rothschild, and John Jacob Astor IV. Work began in 1893 on the Niagara Falls generation project and Tesla's technology was applied to generate electromagnetic energy from the falls.

Edison went on to carry out a campaign to discourage the use of alternating currents, what today would be commonly referred to as FUD. Edison did preside personally over several executions of animals, primarily stray cats and dogs, for the benefit of the press to prove that his inferior system of direct current was safer than that of alternating current. Edison's series of animal executions peaked with the electrocution of Topsy the Elephant. Ironically Edison was against capital punishment, but his desire to disparage the superior system of alternating current led to the invention of one of the world's most recognizable killing devices. Edison (or, reportedly, one of his employees) employed the tactics of misusing Tesla's patents to construct the first electric chair for the state of New York in order to promote the idea that alternating current was deadly. Popular myth has it that Edison invented the electric chair solely as a means of impressing the public that alternating current was more dangerous than direct current, and would therefore be the logical choice for electrocutions. In fact, the chair was primarily invented by a few of his employees, in particular Harold P. Brown, working at Menlo Park (though Edison certainly monitored their operations). [1]

Some doubted that the system would generate enough electricity to power industry in Buffalo. Tesla was sure it would work, saying that Niagara Falls had the ability to power the entire eastern U.S. On November 16, 1896, the first transmission of electrical power between two cities was sent from Niagara Falls to industries in Buffalo from the first commercial two-phase power plants (known as hydroelectric generators) at the Edward Dean Adams Station. The hydroelectric generators were built by Westinghouse Electric Corporation from Tesla's AC system patent designs. Tesla's system designs alleviated the limitations of the previous DC methods. The nameplates on the generators bear Tesla's name. He also set the 60 hertz standard for North America. It took five years to complete the whole facility.

Edison's inventions using direct current ultimately lost to alternating current devices proposed by others: primarily Tesla's polyphase systems and other contributors, such as Charles Proteus Steinmetz (of General Electric). With the financial backing of George Westinghouse, Tesla's AC replaced DC, enormously extending the range and improving the safety and efficiency of power distribution. Tesla's Niagara Falls system marked the end of Edison's roadmap for electrical transmission. Eventually, Edison's GE company converted to the AC system.

See also

   * Electricity
   * Thomas Edison
   * George Westinghouse 

Thomas Edison[edit]

From Wikipedia, the free encyclopedia.

Thomas Alva Edison

Thomas Alva Edison (February 11, 1847 - October 18, 1931) was a United States inventor and businessman who developed many important devices. "The Wizard of Menlo Park" was one of the first inventors to apply the principles of mass production to the process of invention.

Edison was considered one of the most prolific inventors of his time, holding a record 1,093 patents in his name. Most of these inventions were not completely original but improvements of earlier patents, and were actually made by his numerous employees - Edison was frequently criticized for not sharing the credits. Nevertheless, Edison received patents worldwide, including the United States, United Kingdom, France, and Germany. Edison started the Motion Picture Patents Company, which was a conglomerate of nine major film studios (commonly known as the Edison Trust).

Life magazine (USA), in a special double issue, placed Edison first in the "100 Most Important People in the Last 1000 Years", claiming his light bulb "lit up the world", although the first light bulb was pioneered by Heinrich Goebel (who does not even appear on Life's list). Edison's placement has been criticized as misunderstood patriotism, since even during his lifetime there were non-US inventors whose inventions (combustion engines, cars, electricity-making machines, etc.) are believed by many to have had greater impact than Edison's. Edison's placement may have been due to his 1,093 patents.

Table of contents [showhide] 1 Early years 2 Middle years 2.1 Menlo Park 2.2 Incandescence era 2.3 War of Currents era 2.4 Work relations 2.5 Media inventions 3 Later years 4 Personal life 5 List of contributions 6 Improvements of Edison's work 7 External links

Early years

Thomas Edison was born in Milan, Ohio and grew up in Port Huron, Michigan. Partially deaf since adolescence, he became a telegraph operator in the 1860s, and a famously fast one. Some of his earliest inventions related to electrical telegraphy, including a stock ticker.

Edison had worked for a time in his youth selling snacks, and candy on the railroad, labored as a pig slaughterer and started a business selling vegetables. He could reputedly guess a man's weight correctly by simply looking at him. Around 1862, Edison printed and published "The Weekly Herald". It was the first newspaper typeset and printed on a moving train. The Times featured a story on Edison and his paper. Edison applied for his first patent, the electric vote recorder, on October 28, 1868.

Middle years Thomas Edison began his career as an inventor in Newark, New Jersey with the stockticker and improved telegraphic devices being invented there, but the invention which first gained Edison wide fame was the phonograph in 1877. While non-reproducible sound recording was first achieved by Leon Scot de Martinville (France, 1857), and others at the time (notably Charles Cros) were contemplating the notion that sound waves might be recorded and reproduced, Edison was the first to produce a device to actually do so, and this was so unexpected by the public at large as to appear almost magical. Edison became known as "The Wizard of Menlo Park" (after the New Jersey town where he resided). His first phonograph recorded on tinfoil cylinders, had low sound quality, and destroyed the track during replay such that one could listen only once. A redesigned model which used wax cylinders was produced soon after by Alexander Graham Bell. Sound quality was still low and replays were limited before wear destroyed the recording, but the invention enjoyed popularity. The "gramophone", playing disc records was invented by Emile Berliner in 1887; in the early years the audio fidelity was worse than the phonograph cylinders marketed by Edison Records.

Menlo Park Edison's major innovation was the Menlo Park research lab, which was built in New Jersey. It was the first institution set up with the specific purpose of producing constant technological innovation and improvement. Most of the inventions there carried Edison as the inventor, though he mostly just oversaw the operation of his employees.

Most of Edison's patents were utility patents, with only about a dozen being design patents. Many of his inventions were not unique, but Edison showed unique skills in winning the patents and beating his opponents by influence and better marketing. For example, Edison did not invent the electric lightbulb. Several designs had already been developed by earlier inventors including Joseph Swan, Henry Woodward, James Bowman Lindsay, William Sawyer and Heinrich Goebel. Edison took the features of these earlier designs and set his workers the task of producing a longer-lasting bulb. After purchasing the Woodward and Evans patent of 1875 Edison's employees experimented with a large number different materials in order to increase the bulb's burning time. By 1879 they had achieved the goal of increasing the burning time enough to make the lightbulb commercially viable. Whilst the earlier inventors had produced electric lighting in laboratory conditions, Edison was able to bring lighting to homes and businesses by mass-producing long-lasting lightbulbs and creating a system for the generation and distribution of electricity.

Incandescence era

US223898 Electric Lamp In 1878, Edison applied the term "filament" to the element of glowing wire carrying an electric current. In 1878, Edison formed Edison Electric Light Company in New York City with financiers (including J.P. Morgan and the Vanderbilts).

Edison wired his lights by parallel circuit, which causes the current to divide among alternative paths. In parallel circuits, the failure of one light bulb does not cause a circuit to fail, which happens to lamps wired in series. On December 31, 1879, Edison demonstrated incandescent lighting to the public for the first time with some fanfare in Menlo Park, New Jersey. On January 27, 1880 he filed a patent in the United States for the electric incandescent lamp. On February 13, 1880, Edison became the first person to observe the Edison effect. On October 8, 1883 the U.S. patent office ruled that Edison's patent was based on the work of William Sawyer and was invalid.

In 1880, Edison patented electric distribution system. The first investor-owned electric utility was the 1882 Pearl Street Station, New York City. On January 25, 1881, Edison and Alexander Graham Bell formed the Oriental Telephone Company. On September 4, 1882, Edison switched on the world's first electrical power distribution system, providing 110 volts direct current (DC) to 59 customers in lower Manhattan, around his Pearl Street laboratory. On January 19, 1883 the first standardized electric lighting system employing overhead wires began service in Roselle, New Jersey.

Litigation continued until on October 6, 1889, a judge ruled that Edison's electric light improvement claim for "a filament of carbon of high resistance" was valid. Research exposed in "A Streak of Luck" by Robert Conot (1979), shows that Edison and his attorneys hid significant information from the judge, they cut out the October 7-21, 1879 section of a notebook. Edison failed to patent the light bulb in the United Kingdom. After losing a court battle with Swan, they formed a joint company (Ediswan) to market the invention. This company and its technological heritage became a part of General Electric in 1892.

Much of the work leading to the improvement of the lightbulb was done by one of Edison's assistants, Lewis Latimer, an African American.

War of Currents era Main article:War of Currents

During the initial years of electricity distribution, Edison's direct current was the standard for the United States and Edison was not disposed to lose all his patent royalties. During the commonly referred to "War of Currents" era, Serbian immigrant Nikola Tesla and Edison became adversaries due to Edison's promotion of DC for electric power distribution over the more efficient alternating current advocated by Tesla, who patented AC in Graz, Austria. Edison (or, reportedly, one of his employees) employed the tactics of misusing Tesla's patents to construct the first electric chair for the state of New York in order to promote the idea that alternating current was deadly. Popular myth has it that Edison invented the electric chair, despite being against capital punishment, solely as a means of impressing the public that alternating current was more dangerous than direct current, and would therefore be the logical choice for electrocutions. In fact, the chair was primarily invented by a few of his employees, in particular Harold P. Brown, working at Menlo Park (though Edison certainly monitored their operations). [1]

Edison went on to carry out a campaign to discourage the use of alternating current, what today would be commonly referred to as FUD. Edison did preside personally over several executions of animals, primarily stray cats and dogs, for the benefit of the press to prove that his inferior system of direct current was safer than that of alternating current. Edison's series of animal executions peaked with the electrocution of Topsy the Elephant. Ironically, Edison was against capital punishment, but his desire to disparage the superior system of alternating current led to the invention of one of the world's most recognizable killing devices.

Many of Edison's inventions using direct current ultimately lost to alternating current devices proposed by others: primarily Tesla's polyphase systems and other contributors, such as Charles Proteus Steinmetz (of General Electric). AC distribution systems replaced DC, enormously extending the range and improving the safety and efficiency of power distribution. Since the 1950s, High Voltage Direct Current (HVDC) transmission systems have become more common in certain situations. HVDC systems are presently used for some specialised applications like the underwater interconnection of Power Systems.

Work relations

As exemplified by the light bulb story, most of Edison's inventions were improvements of ideas by others, achieved through a diligent and industrial approach and team-based development. He was the undisputed head of the team which usually did not share credit for the inventions. He himself said: "invention is 1% of inspiration and 99% of transpiration." Nikola Tesla, possibly Edison's most famous employee and great scientist in his own right, said about Edison's method of problem-solving: "If Edison had a needle to find in a haystack, he would proceed at once with the diligence of the bee to examine straw after straw until he found the object of his search. I was a sorry witness of such doings, knowing that a little theory and calculation would have saved him ninety per cent of his labor."

At a meeting in late 1885, of Edison, Edward H. Johnson (President of the Edison Illuminating Company), Charles Batchellor (Manager of the Edison works) and Nikola Tesla, one of the group suggested guessing weights and Tesla was induced to step on a scale. Edison guessed that Tesla weighed 152 pounds (69 kg), to an ounce. Johnson confidentially related to Tesla that Edison could guess individuals' weight as he had developed the skill when he was employed for a long time in a Chicago slaughter-house where he weighed thousands of hogs every day.[2]

Media inventions

Initially, it was believed that Thomas Edison invented the motion picture camera, but it has since been proven that William Kennedy Laurie Dickson actually invented it at the Edison laboratories. However, Edison's influence on the history of film stretches beyond that of instigator. He became a powerhouse of film production and must be given credit for establishing the standard of using 35 mm celluloid film with 4 perforations on the edge of each frame that allowed film to emerge as a mass medium and not just a vaudeville novelty. He built what has been called the first movie studio, the Black Maria in New Jersey. Here he made the first copyrighted film, Fred Ott's Sneeze.

His inventions benefited people world wide and in 1878, he was appointed Chevalier of the Legion of Honor of France and in 1889 was made Commander of the Legion of Honor.

On September 30, 1890, Edison obtained patent US437422 for telegraphy, US437423, US437424, US437426 for the phonograph, US437425 for a phonograph-recorder, US437427 for a "Method of Making Phonograph Blanks", US437428 for a "Propelling Device for Electrical Cars", and US437429 for a phonogram blank.

In 1891, Thomas Edison built a Kinetoscope, or peep-hole viewer. This device was installed in penny arcades where people could watch short, simple films. This was important to Thomas Edison especially because he had been searching for a way to entertain customers that were listening to music on his phonograph. Now, people could go to a penny arcade, put in a coin, put on the headphones and watch a film through the peep-hole. Later that same year, on December 29th, Edison patented the radio ("transmission of signals electrically").

On August 9, 1892, Edison received a patent for a two-way telegraph.

Later years

In West Orange, New Jersey on February 1, 1893 Edison finished construction of "Black Maria", the first motion picture studio. However, a United States court of appeals ruled on March 10, 1902 that Edison did not invent the movie camera and thus could not exercise monopoly power over its use (see Edison v. American Mutoscope). In 1894, Edison experiments with synchronizing audio with film; the Kinetophone was invented which loosely synchronizes a Kinetoscope image with a cylinder phonograph. In April of 1896, Edison and Thomas Armat's Vitascope were used to project motion pictures in public screenings in New York City.

Thomas Edison submitted his last patent application, "Holder for Article to be Electroplated", on January 6, 1931 and died later that year. The patent was granted two years later in 1933.

Personal life

He was married twice, the first time in 1871 to Mary Stilwell (1855-1884), with whom he had three children - Marion Estelle, Thomas Jr., and William Leslie - before she died at age 29, probably of typhoid fever. His second marriage was to Mina Miller (1865-1946), also with three children, Madeleine, Charles (who took over the company), and Theodore Miller. Thomas Edison was an atheist.

List of contributions

   * Phonograph
   * Kinetoscope
   * dictaphone
   * radio
   * electric bulb
   * autographic printer
   * tattoo gun 

For a discussion of Edison's Record company and its role in the recording industry, see: Edison Records

Improvements of Edison's work

   * Lewis Latimer patented an improved method of producing the filament in light bulbs.
   * Nikola Tesla developed alternating current distribution, which could be used to transmit electricity over longer distance than Edison's direct current due to the ability to transform the voltage. 

External links

Biography

   * Dyer, Frank Lewis, "Edison, His Life And Inventions". (Worldwideschool.org)
   * Beals, Gerry, "Thomas Edison"
   * Murphy, John Patrick Michael, "Thomas Alva Edison" 

Historic Sites

   * Edison Birthplace Museum
   * Thomas Edison House
   * Edison National Historic Site 
   * Henry Ford Museum & Greenfield Village

Archives

   * Thomas A. Edison Papers at Rutgers University
   * Thomas Edison's Patents - Rutgers University
   * Edisonian Museum Antique Electrics
   * Thomas A. Edison in his laboratory in New Jersey, 1901
   * "Edison's Miracle of LIght". American experience, PBS. 

Relations

   * One Story of Nikola Tesla : Anecdotes concerning the relationship of Tesla and Edison. 

Writings and Speech

   * Thomas Edison Quotations
   * Edison, Thomas A., The Philosophy of Thomas Paine. June 7, 1925. (essay) 

See also Light Bulb

Incandescent light bulb[edit]

(Redirected from Light Bulb)

tungsten-halogen 18-25 [6] 2.6%-3.6% 13W twin-tube fluorescent 56.3 [1] 8.2% compact fluorescent 45-60 [4] 15%-32% [3] xenon arc lamp 30-150 [5] 4.4%-22% mercury-xenon arc lamp 50-55 [5] 7.3%-8% high-temperature incandescent 35 [2] 5.14% ideal blackbody radiator 95 [2] 14% [7] ideal white light source 242.5 [2] 36% monochromatic 556nm source 680 [7] 100%

   [1] http://www.dgs.state.md.us/lighting/faqs.html 
   [2] http://freespace.virgin.net/tom.baldwin/bulbguide.html 
   [3] http://www.homefamily.net/consumer/energyefficiency.html 
   [4] http://www.coffj.com/veg1/lamp.htm 
   [5] http://www.pti-nj.com/obb_lamps.html 
   [6] http://www.chipcenter.com/eexpert/akruger/akruger044.html 
   [7] http://physics.ccri.cc.ri.us/keefe/light.htm 

Heat A fluorescent lamp, which is approximately 8 times more efficient than an incandescent lamp, will produce 8 times less heat, assuming the same levels of light from both sources. This is one reason why fluorescent lighting is so popular in commercial spaces.

Voltage, light output, and life Incandescent lamps are extraordinarily sensitive to changes in the supply voltage. These characteristics are of great practical and economic importance. For a supply voltage V,

   * Light output is approximately proportional to V3.4
   * Power consumption is approximately proportional to V1.6
   * Life is approximately inversely proportional to V16 (!!!!)
   * Color temperature is approximately proportional to V0.42 

This means that 5% reduction in operating voltage will double the life of the bulb, at the expense of reducing its light output by 20%. This may be a very acceptable tradeoff for a light bulb that is a difficult-to-access location. So-called "long-life" bulbs are simply bulbs in which this tradeoff is designed in.

According to the relationships above (which are probably not accurate for such extreme departures from nominal ratings), operating a 100-watt, 1000-hour, 1700-lumen bulb at half voltage would extend its life to about 65,000,000 hours or over 7000 years—while reducing light output to 160 lumens, about the equivalent of a normal 15-watt bulb. A television news story once reported on a firehouse in which a light bulb was said to have been burning continuously for over a century. The story treated this as amusing but inexplicable phenomenon. Footage showed that the bulb was putting out very little light and that the filament was glowing a dim orange. The story is thus perfectly credible; had the reporter dug deeper, it would probably have transpired that this was no miracle, but simply a 240-volt bulb being operated on a 120-volt supply.

In photoflood bulbs used for photographic lighting, the tradeoff is made in the other direction. Compared to general service bulbs, for the same wattage, these bulbs produce far more light, and (more importantly) light at a higher color temperature, at the expense of greatly reduced life (which may be as short as 2 hours for a type P1 lamp). The upper limit to the temperature at which metal incandescent bulbs can operate is the melting point of the metal. Tungsten is the metal with the highest melting point. A 50 hour life projection bulb, for instance, is designed to operate only 50 degrees C below that melting point.

See also

   * Arc lamp
   * Fluorescent light
   * Lightbulb jokes
   * Light emitting diode (LED)
   * Neon light
   * Timeline of lighting technology
   * Thomas Edison 

External links, references, resources

   * Edward J. Covington's Early Incandescent Lamps
   * Great Internet Light Bulb Book
   * Technical Information on Lamps
   * Kruger, Anton, "When Can LEDs Replace Incandescent Lamps"?
   * Worth Knowing?! — Technology: Bulb
   * Light Bulbs: How They Work

George Westinghouse[edit]

From Wikipedia, the free encyclopedia.


George Westinghouse Industrial entrepreneur

George Westinghouse (October 6, 1846 - March 12, 1914) was a conscientious employer and fair entrepreneur. The name of Westinghouse is as or more familiar as that of Edison, but only as a trademark and company name. Thomas Alva Edison remains a famous public figure but his contemporary George Westinghouse is now largely anonymous. This is somewhat strange, since the accomplishments of both men were comparable in breadth and importance.

Table of contents [showhide] 1 Early years 2 Middle years 3 Later years 4 Death and afterwards 5 See also

Early years

George Westinghouse was born in Central Bridge, New York, on October 6 1846. In the mid-1850s, his father, George Westinghouse Senior, established a factory in Schenectady, New York, where young George learned about mechanics, manufacturing, management, and business. After the outbreak of the American Civil War in 1861, the 15-year-old George ran away with two of his brothers to fight for the Union cause. One of the brothers was killed in action. George transferred to the Union Navy to become a ship's engineer.

George Westinghouse returned to Schenectady after the end of the war in 1865, where he studied engineering at Union College while he dreamed up new inventions, mostly related to the railroads. At the time, the safety record of the railroads was appalling, and he became interested in designing improvements that would make trains safer and more efficient to operate.

His first major invention was a device to mount railroad cars back on tracks after they had been derailed. After watching a collision between two trains, he invented an improved braking system that could be operated by the locomotive engineer, without the delay of going through a brakeman.

Such systems had been invented before, based on steam or chains, but had not proven effective. Westinghouse invented a new system that used compressed air. This original Westinghouse braking system was not "fail-safe", but he refined the design until it was, and also worked towards standardization of air brake systems to ensure interoperability between different train lines. In 1893, the US Railroad Safety Appliance Act made air brakes mandatory on all trains in the US, and air brakes remain standard on railroads, trucks, and buses even today.

In 1868, Westinghouse went to Pittsburgh, Pennsylvania, where the next year he set up the Westinghouse Air Brake Company. His air-brake system established his reputation and fortunes. He moved on develop a new automatic signal and switching system using electricity and compressed air, as well as improved car couplers.

He then began to expand the scope of his activities. Oil was becoming increasingly important for industrial purposes. Oil drilling tended to release natural gas, which was simply wasted because there was no way to deal with it. Westinghouse developed improved drilling equipment that could handle natural gas, as well as the elements of piping systems needed to distribute the gas.

The invention of the telephone by Alexander Graham Bell in 1877 led Westinghouse into a new domain. At first, all telephone calls were routed through a central switchboard, but this led to a tangle of wiring. In 1879, Westinghouse introduced automated substations that could route calls to a central exchange, greatly reducing the number of connections. Such a "hierarchical" switching system would eventually be expanded into the modern switched telephone network.

Middle years

In 1875, Thomas Edison had been a virtual unknown. He had achieved some success with a "multiplex telegraph" system that allowed multiple telegraph signals to be sent over a single wire, but had not yet obtained the recognition he wanted. He was working on a telephone system but was upstaged by Bell. Edison bounced back quickly from the setback to invent the phonograph, which was a public sensation nobody had dreamed possible and made him famous.

Edison's next step, in 1878, was to invent an improved incandescent light bulb, and more the point to consider the need for an electrical distribution system to provide power for light bulbs. On September 4 1882, Edison switched on the world's first electrical power distribution system, providing 110 volts direct current (DC) to 59 customers in lower Manhattan, around his Pearl Street laboratory.

Westinghouse's interests in gas distribution and telephone switching logically led to become interested in electrical power distribution. He investigated Edison's scheme, but decided that it was too inefficient to be scaled up to a large size. Edison's power network was based on low-voltage DC, which meant large currents and serious power losses. Several European inventors were working on "alternating current (AC)" power distribution. An AC power system allowed voltages to be "stepped up" by a transformer for distribution, reducing power losses, and then "stepped down" by a transformer for use.

A power transformer developed by Lucien Gaulard of France and John Gibbs of England was demonstrated in London in 1881, and attracted the interest of Westinghouse. Transformers were nothing new, but the Gaulard-Gibbs design was one of the first that could handle large amounts of power and promised to be easy to manufacture. In 1885, Westinghouse imported a number of Gaulard-Gibbs transformers and a Siemens AC generator to begin experimenting with AC networks in Pittsburgh.

Assisted by William Stanley, Westinghouse worked to refine the transformer design and build a practical AC power network. In 1886, Westinghouse and Stanley installed the first multiple-voltage AC power system in Great Barrington, Massachusetts. The network was driven by a hydropower generator that produced 500 volts AC. The voltage was stepped up to 3,000 volts for transmission, and then stepped back down to 100 volts to power electric lights. That same year, he formed the "Westinghouse Electric & Manufacturing Company", which was renamed the "Westinghouse Electric & Manufacturing Company" in 1889.

Thirty more AC lighting systems were installed within a year, but the scheme was limited by the lack of an effective metering system and an AC electric motor. In 1888, Westinghouse and his engineer Oliver Shallenger developed a power meter, which they designed to look as much like a gas meter as possible. The same basic meter technology is still used today.

An AC motor was a more difficult task, but fortunately a design was already available, at least in principle. The brilliant Serbian inventor Nikola Tesla had already dreamed up the basic principles of a polyphase electric motor. As luck would have it, he had come to the United States while in the employ of the Edison company. Tesla and Edison didn't get along well, one reason being that Tesla was interested in AC systems, and quickly parted company.

Westinghouse got in touch with Tesla, and obtained patent rights to Tesla's AC motor. Tesla hadn't actually built a working motor at that time, but Westinghouse hired him as a consultant for a year and helped turn his polyphase AC motor into a reality. The work led to the standard modern US power-distribution scheme: three-phase AC at 60 Hz. This was chosen as a rate high enough to minimize light flickering, but low enough to reduce reactive losses.

Westinghouse's promotion of AC power distribution led him into a bitter confrontation with Edison and his DC power system. The feud became known as "the War of Currents." Edison claimed that high voltage systems were inherently dangerous; Westinghouse replied that the risks could be managed and were outweighed by the benefits. Edison tried to have legislation enacted in several states to limit power transmission voltages to 800 volts, but failed.

The battle went to an absurd, and some would say tragic, level, when in 1887 a board appointed by the state of New York consulted Edison on the best way to execute condemned prisoners. At first, Edison wanted nothing to do with the matter, declaring his opposition to capital punishment.

However, Westinghouse AC networks were clearly winning the battle of the currents, and the ultra-competitive Edison saw a last opportunity to defeat his rival. Edison hired an outside engineer named Harold P. Brown, who could pretend to be impartial, to perform public demonstrations in which animals were electrocuted by AC power. Edison then told the state board that AC was so deadly that it would kill instantly, making it the ideal method of execution. His prestige was so great that his recommendation was adopted.

Harold Brown then sold gear for performing electric executions to the state for $8,000. In August 1890, a convict named William Kemmler became the first person to be executed by electrocution. The execution was messy and protracted, and Westinghouse protested that they could have done better with an axe. Unfortunately, the electric chair became a common form of execution for decades, even though it had proven from the first to be an unsatisfactory way to do the job. However, Edison failed in his attempts to have the procedure named "Westinghousing".

Edison also failed to discredit AC power, whose advantages did in fact well outweigh its hazards. Even General Electric, formed with Edison's backing in Schenectady in 1892, decided to begin production of AC equipment.

Later years

In 1893, in a significant coup, the Westinghouse company was awarded the contract to set up an AC network to power the World's Columbian Exposition in Chicago, giving the company and the technology widespread positive publicity. Westinghouse also received a contract to set up the first long-range power network, with AC generators at Niagara Falls producing electricity for distribution in Buffalo, New York, 40 kilometers (25 miles) away.

With AC networks expanding, Westinghouse turned his attention to electrical power production. At the outset, the available generating sources were hydroturbines where falling water was available, and reciprocating steam engines where it was not. Westinghouse felt that reciprocating steam engines were clumsy and inefficient, and wanted to develop some class of "rotating" engine that would be more elegant and efficient.

In fact, one of his first inventions had been a rotary steam engine, but it had proven impractical. However, an English engineer named Charles Parsons began to experiment with steam turbines in 1884, beginning with a 10 horsepower (7.5 kW) unit. Westinghouse bought rights to the Parsons turbine in 1885, and began work towards improving the Parsons technology and scaling it up.

Skeptics questioned that the steam turbine would ever be a reliable large-scale power source, but in 1898 Westinghouse demonstrated a 300 kilowatt unit, replacing reciprocating engines in his air-brake factory. The next year he installed a 1.5 megawatt, 1,200 rpm unit for the Hartford Electric Light Company.

Westinghouse then turned his attention to using such large steam turbines to drive big ships. The problem was that such large turbines were most efficient at about 3,000 rpm, while an efficient propeller operated at about 100 rpm. That meant reduction gearing, but building a reduction gear system that could operate at such high rpm and at high power was tricky. Even a slight misalignment would shake the power train to pieces. Westinghouse and his engineers were able to devise an automatic alignment system that made turbine power practical for large vessels.

Westinghouse remained productive and inventive through almost all his life. Like Edison, he had a practical and experimental streak. At one time, Westinghouse began to work on heat pumps that could provide heating and cooling, and even believed that he might be able to extract enough power in the process for the system to run itself.

Any modern engineer would clearly see that Westinghouse was after a perpetual motion machine, and the British physicist Lord Kelvin, one of Westinghouse's correspondents, told him that he would be violating the laws of thermodynamics. Westinghouse replied that might be the case, but it made no difference. If he couldn't built a perpetual-motion machine, he would still have a heat pump system that he could patent and sell.

With the introduction of the automobile after the turn of the century, Westinghouse went back to earlier inventions and came up with a compressed-air shock absorber scheme to allow automobiles to deal with the wretched roads of the time.

Westinghouse remained a captain of American industry until 1907, when a financial panic led to his resignation from control of the Westinghouse company. By 1911, he was no longer active in business, and his health was in decline.

Death and afterwards

George Westinghouse died on March 12 1914, in New York City, at age 67. As a Civil War veteran, he was buried in Arlington National Cemetery, along with his wife Marguerite. He was mourned. Although a shrewd and determined businessman, Westinghouse was a conscientious employer and wanted to make fair deals with his business associates. In 1930, a memorial to Westinghouse, funded by his employees, was placed in Schenley Park in Pittsburgh.

See also

   * Air brake
   * Electric motor
   * Electric power
   * Electricity
   * Greg Goebel
   * List of electrical engineers
   * List of inventors
   * Nikola Tesla
   * Progressive Generation
   * Reginald Fessenden
   * Steam turbine
   * Telluride, Colorado
   * Thomas Edison
   * Timeline of invention
   * Timeline of transportation technology
   * War of Currents
   * Westinghouse Electric Corporation
   * William Kemmler 

The original version of this article was by greg_goebel (gvgoebel@yahoo.com) / public domain. This article is a composite work licensed under the GFDL.