Christmas is time of celebration, music, good proposals and light. They have been talking about Thomas Alva Edison, who demonstrates incandescent lighting to the public for the first time, in Menlo Park, New Jersey on a day like today in 1879. Edison wasn't the only inventor to lay claim to the light bulb and the history of this invention has as inventors as guests had The Grandma on a day so special.
An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated until it glows.
The filament is enclosed in a glass bulb to protect the filament from oxidation. Current is supplied to the filament by terminals or wires embedded in the glass. A bulb socket provides mechanical support and electrical connections.
Incandescent bulbs are manufactured in a wide range of sizes, light output, and voltage ratings, from 1.5 volts to about 300 volts.
They require no external regulating equipment, have low manufacturing costs, and work equally well on either alternating current or direct current. As a result, the incandescent bulb became widely used in household and commercial lighting, for portable lighting such as table lamps, car headlamps, and flashlights, and for decorative and advertising lighting.
Incandescent bulbs are much less efficient than other types of electric lighting, converting less than 5% of the energy they use into visible light. The remaining energy is lost as heat. The luminous efficacy of a typical incandescent bulb for 120 V operation is 16 lumens per watt, compared with 60 lm/W for a compact fluorescent bulb or 150 lm/W for some white LED lamps.
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Some applications use the heat generated by the filament. Heat lamps are made for uses such as incubators, lava lamps, and the Easy-Bake Oven toy. Quartz tube lamps are used for industrial processes such as paint curing or for space heating.
Incandescent bulbs typically have short lifetimes compared with other types of lighting; around 1,000 hours for home light bulbs versus typically 10,000 hours for compact fluorescents and 20,000-30,000 hours for lighting LEDs.
Incandescent bulbs can be replaced by fluorescent lamps, high-intensity discharge lamps, and light-emitting diode lamps (LED). Some areas have implemented phasing out the use of incandescent light bulbs to reduce energy consumption.
Historians Robert Friedel and Paul Israel list 22 inventors of incandescent lamps prior to Joseph Swan and Thomas Edison. They conclude that Edison's version was able to outstrip the others because of a combination of three factors: an effective incandescent material, a higher vacuum than others were able to achieve by use of the Sprengel pump and a high resistance that made power distribution from a centralized source economically viable.
Historian Thomas Hughes has attributed Edison's success to his development of an entire, integrated system of electric lighting.
Thomas Edison began serious research into developing a practical incandescent lamp in 1878.
Edison filed his first patent application for Improvement in Electric Lights on 14 October 1878.
After many experiments, first with carbon in the early 1880s and then with platinum and other metals, in the end Edison returned to a carbon filament. The first successful test was on 22 October 1879, and lasted 13.5 hours.
Edison continued to improve this design and by 4 November 1879, filed for a US patent for an electric lamp using a carbon filament or strip coiled and connected... to platina contact wires.
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Although the patent described several ways of creating the carbon filament including using cotton and linen thread, wood splints, papers coiled in various ways, Edison and his team later discovered that a carbonized bamboo filament could last more than 1200 hours.
In 1880, the Oregon Railroad and Navigation Company steamer, Columbia, became the first application for Edison's incandescent electric lamps, it was also the first ship to use a dynamo.
More than 95% of the power consumed by a typical incandescent light bulb is converted into heat rather than visible light. Other electrical light sources are more effective.
For a given quantity of light, an incandescent light bulb consumes more power and gives off more heat than a fluorescent lamp. In buildings where air conditioning is used, incandescent lamps' heat output increases load on the air conditioning system. While heat from lights will reduce the need for running a building's heating system, in general a heating system can provide the same amount of heat at a lower cost than incandescent lights.
Halogen incandescent lamps will use less power to produce the same amount of light compared to a non-halogen incandescent light. Halogen lights produce a more constant light-output over time, without much dimming.
More information: The New York Times
Thomas Alva Edison