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The invention of the light bulb is sometimes attributed to Thomas Alva Edison, who made contributions to its development and marketing, but today it is well-known that Heinrich GöbelHeinrich Gobel ( April 20, 1818 December 4, 1893), born in Germany, was an inventor, an early pioneer who did much work on developing the light bulb. In 1844, he married Sophie Lubke. At the age of 31, he emigrated to New York City, USA, where he lived un built functional bulbs three decades earlier. Many others also contributed to the development of a truly practical device for the production of electrically generated lighting.
In 1801 Sir Humphry DavySir Humphry Davy ( December 17, 1778 May 29, 1829), often incorrectly spelled Humphrey was an English chemist. He was born in Penzance, Cornwall, England. Davy became well known owing to his experiences with the physiological action of some gases, includi, an EnglishEngland is the largest, the most populous, and the most densely populated of the four " Home Nations" which make up the United Kingdom of Great Britain and Northern Ireland (UK). Occupying the south-eastern portion of the island of Great Britain, England chemist, made platinumPlatinum is also a certification by the RIAA and other world recording industries, see: RIAA certification Platinum is a chemical element in the periodic table that has the symbol Pt and atomic number 78. A heavy, malleable, ductile, precious, gray-white strips glow by passing an electric current through them, but the strips evaporated too quickly to make a useful lamp. In 1809 he created the first arc lampAn arc lamp is a device that produces light by the sparking (or arcing, from voltaic arc) of a high current between two carbon rod electrodes. The rods are touched and then slowly drawn apart; as the rods separate the current is "struck" and arcs across t, which he demonstrated to the Royal InstitutionThe Royal Institution of Great Britain was set up in 1799 by the leading lights of the age, including Henry Cavendish and its first president George Finch, the 9th Earl of Winchilsea, for "diffusing the knowledge, and facilitating the general introduction of Great Britain in 1810Events January 10 Marriage of Napoleon and Josephine is annulled January 20 Tyrolean rebel leader Andreas Hofer executed March 11 Napoleon marries Marie-Louise of Austria April 19 Venezuela achieves home rule: Emparan, Governor of the Captaincy General is, by creating a small but blinding arc between two charcoal rods connected to a battery.
In 1820 a British scientist Warren De la Rue enclosed a platinum coil in an evacuated tube and passed an electric current through it. The design was based on the concept that the high melting point of platinum would allow it to operate at high temperatures and that the evacuated chamber would contain less gas particles to react with the platinum, improving its longevity. Although it was an efficient design, the cost of the platinum made it impractical for commercial use.
In 1835 James Bowman Lindsay demonstrated a constant electric light at a public meeting in Dundee. He stated that he could "read a book at a distance of one and a half foot". However having perfected the device, to his own satisfaction, he turned to the problem of wireless telegraphy and did not develop the electric light any further.
In 1841 Frederick de Moleyns of England was granted the first patent for an incandescent lamp, with a design using powdered charcoal heated between two platinum wires.
In 1854, the German inventor Heinrich Göbel developed the first 'modern' light bulb: a carbonized bamboo filament, in a vacuum bottle to prevent oxidation. In the following five years he developed what many call the first practical light bulb. His lamps lasted for up to 400 hours. He did not immediately apply for a patent, but his priority was established in 1893.
Joseph Wilson Swan (1828-1914) was a physicist and chemist born in Sunderland, England. In 1850 he began working with carbonized paper filaments in an evacuated glass bulb. By 1860 he was able to demonstrate a working device but lack of a good vacuum and an adequate supply of electricity resulted in a short lifetime for the bulb and inefficient light. By the mid-1870s better pumps became available, and Swan returned to his experiments. Swan received a British patent for his device in 1878. Swan reported success to the Newcastle Chemical Society and at a lecture in Newcastle in February 1879 he demonstrated a working lamp that utilized a carbon fibre filament. The most significant feature of Swan's lamp was that there was little residual oxygen in the vacuum tube to ignite the filament, thus allowing the filament to glow almost white-hot without catching fire. From this year he began installing light bulbs in homes and landmarks in England and by the early 1880s had started his own company.Across the Atlantic, parallel developments were also taking place. On July 24 1874 a Canadian patent was filed for the Woodward and Evan's Light by a Toronto medical electrician named Henry Woodward and a colleague Mathew Evans, who was described in the patent as a "Gentleman" but in reality a hotel keeper. They built their lamp with a shaped rod of carbon held between electrodes in a glass bulb filled with nitrogen. Woodward and Evans found it impossible to raise financial support for the development of their invention and in 1875 Woodward sold a share of their Canadian patent to Thomas Edison.
Edison purchased the Woodward and Evans patent and had a team of developers search for an alternative filament material. Eventually he used a carbon filament that burned for forty hours (first successful test was on October 21 1879; it lasted 13 1/2 hours). Edison continued to improve their design. By 1880 he had a device that could last for over 1200 hours using a bamboo-derived filament, longer than the 400 hours of Heinrich Goebel's earlier light bulb.
In January 1882, Lewis Latimer received a patent for the "Process of Manufacturing Carbons," an improved method for the production of light-bulb filaments which yielded longer lasting bulbs than Edison's technique.
In Britain, Swan took Edison to court for patent infringement. Edison lost and as part of the settlement, Edison was forced to take Swan in as a partner in his British electric works. The company was called the Edison and Swan United Electric Company. Eventually, Edison acquired all of Swan's interest in the company. Swan sold his U.S. patent rights to the Brush Electric Company in June 1882.
The U.S. Patent Office had ruled on October 8, 1883 that Edison's patents were based on the prior art of William Sawyer and were invalid. Litigation continued for a number of years. Eventually 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 that the judge might have determined showed that they were simply extending Sawyer's (or Swan's) work with carbon "burners" or "rods" in an evacuated glass bulb.
Edison and his team did not find a commercially workable filament (bamboo) until more than 6 months after Edison filed the patent application. The weak and short lived (40-150 hours) carbon filament was eventually superseded by the tungsten filament. In 1903 Willis Whitnew invented a filament that would not blacken the inside of a lightbulb. It was a metal-coated carbon filament. In 1906, the General Electric Company was the first to patent a method of making tungsten filaments for use in incandescent lightbulbs. The filaments were costly, but by 1910 William David Coolidge ( 1873- 1975) had invented an improved method of making tungsten filaments. The tungsten filament outlasted all other types of filaments and Coolidge made the costs practical.
One of the major problems of the standard electric light bulb is evaporation of the filament, leading to narrowing. Where the filament is narrower, electrical resistance is higher (due to the smaller cross-section) and the filament heats up more, increasing the rate of evaporation further at that point. The end point of this process is the failure of the filament.
A typical filament light bulb lasts about 1000 hours. See the section below, Voltage, light output, and life, for a discussion of the tradeoffs involved is setting a lamp life specification.
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