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A street light, light pole, lamp pole, lamppost, streetlamp, light standard, or lamp standard is a raised source of light on the edge of a road or path. Similar lights may be found on a railway platform. When urban electric power distribution became ubiquitous in developed countries in the 20th century, lights for urban streets followed, or ...
A sodium-vapor lamp is a gas-discharge lamp that uses sodium in an excited state to produce light at a characteristic wavelength near 589 nm. Two varieties of such lamps exist: low pressure and high pressure. Low-pressure sodium lamps are highly efficient electrical light sources, but their yellow light restricts applications to outdoor ...
Gas lamps gradually started replacing oil street lamps in the United States, beginning in the first quarter of the 19th century. [3] The first street in the world to be illuminated by gaslight was Pall Mall in London, starting in 1807. [1][5] The first US city to use gas street lights was Baltimore, starting in 1817. [4]
Most solar lights turn on and turn off automatically by sensing outdoor light using solar panel voltage. Solar streetlights are designed to work throughout the night. Many can stay lit for more than one night if the sun is not in the sky for an extended period of time. Older models included lamps that were not fluorescent or LED.
Traffic light control and coordination. A junction for road vehicles and pedestrians controlled by traffic lights in the UK. The various vehicle and pedestrian movements are separated in either time or space for safety and efficiency. The normal function of traffic lights requires more than sight control and coordination to ensure that traffic ...
It was installed by the American Traffic Signal Company on the corner of East 105th Street and Euclid Avenue in Cleveland, Ohio. [10] [11] [12] The first four-way, three-colour traffic light was created by William Potts in Detroit, Michigan in 1920. [13] His design was the first to include an amber 'caution' light along with red and green ...
The flat bottom surfaces of the anvil and post embedded inside the epoxy act as anchors, to prevent the conductors from being forcefully pulled out via mechanical strain or vibration. A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron ...
e. Electrical wiring in North America follows the regulations and standards applicable at the installation location. It is also designed to provide proper function, and is also influenced by history and traditions of the location installation. The US National Electrical Code is applicable to many areas in the US where state, county or local ...