Incandescent lamps are nearly pure resistive loads with a power factor of 1. Unlike discharge lamps or LED lamps, the power consumed is equal to the apparent power in the circuit. Incandescent light bulbs are usually marketed according to the electrical power consumed. This depends mainly on the operating resistance of the filament. For two bulbs of the same voltage, and type, the higher-powered bulb gives more light. The heat produced by filaments is used in some applications, such as heat lamps in incubators, lava lamps, and the Easy-Bake Oven toy. Quartz envelope halogen infrared heaters are used for industrial processes such as paint curing and space heating. Plagiarism is never tolerated. Writers and editors caught stealing content or improperly citing sources are immediately terminated, and we will work to rectify the situation with the original publisher(s)

The Sleep Foundation editorial team is dedicated to providing content that meets the highest standards for accuracy and objectivity. Our editors and medical experts rigorously evaluate every article and guide to ensure the information is factual, up-to-date, and free of bias.In 1840, British scientist Warren De la Rue enclosed a coiled platinum filament in a vacuum 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 fewer gas molecules to react with the platinum, improving its longevity. Although a workable design, the cost of the platinum made it impractical for commercial use. Exposure to bright lights and cool-toned colors, such as blue light from cell phones, computers, and televisions, can inhibit melatonin production and keep a person awake. A dark room is best for sleep. However, in the hours before bed, warmer hues of light, such as yellows and oranges, are preferable to cooler light, like blue light from electronic devices. This is because light plays a critical role in regulating our sleep and wakefulness.

a b "Reports of Companies". Electrical Engineer, Volume 10. Electrical Engineer. 16 July 1890. p.72. Archived from the original on 26 January 2017 . Retrieved 18 October 2016. The Consolidated Company was the successor of the Electro-Dynamic Light Company of New York, the first company organized in the United States for the manufacture and sale of electric incandescent lamps, and the owner of a large number of patents of date prior to those upon which rival companies were depending. ... The United States Electric Lighting Company was organized in 1878, a few weeks after the Electro-Dynamic Company a b "Dec. 18, 1878: Let There Be Light — Electric Light". WIRED. 18 December 2009. Archived from the original on 21 October 2016. High Efficiency Incandescent Lighting | MIT Technology Licensing Office". tlo.mit.edu . Retrieved 19 August 2022. In 1897, German physicist and chemist Walther Nernst developed the Nernst lamp, a form of incandescent lamp that used a ceramic globar and did not require enclosure in a vacuum or inert gas. [54] [55] Twice as efficient as carbon filament lamps, Nernst lamps were briefly popular until overtaken by lamps using metal filaments. In Britain, the Edison and Swan companies merged into the Edison and Swan United Electric Company (later known as Ediswan, and ultimately incorporated into Thorn Lighting Ltd). Edison was initially against this combination, but Edison was eventually forced to cooperate and the merger was made. Eventually, Edison acquired all of Swan's interest in the company. Swan sold his US patent rights to the Brush Electric Company in June 1882.

Lamps operated on direct current develop random stairstep irregularities on the filament surface which may cut lifespan in half compared to AC operation; different alloys of tungsten and rhenium can be used to counteract the effect. [113] [114] Light Sensitivity, Scientific Committee on Emerging and Newly Identified Health Risks" (PDF). Director-General for Health and Consumers, European Commission. 2008. pp.26–27. Archived (PDF) from the original on 12 November 2008 . Retrieved 31 August 2009. It will boost your mood, strengthen your bones, and improve vision. Plus, you will be less prone to stress and depression. Yellow light