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A headlamp or headlight (known as a head torch in the UK) is a light source affixed to the head for outdoor activities at night or in dark conditions such as caving, orienteering, hiking, skiing, backpacking, camping, mountaineering or mountain biking. Headlamps may also be used in adventure races. Headlamps are often used by workers in underground mining, search and rescue, surgeons, and by other workers who need hands-free lighting.
Headlamps are usually powered by three or four AA or AAA batteries. Systems with heavy batteries (4xAA or more) are usually designed so that the light emitter is positioned near the front of the head, with the battery compartment at the rear of the head.[ citation needed ] The headlamp is strapped to the head or helmet with an elasticized strap. It is sometimes possible to completely disconnect a headlamp's battery pack, for storage on a belt or in a pocket.
Lighter headlamp systems are strapped to the user's head by a single band; heavier ones utilize an additional band over the top of the user's head.[ citation needed ]
White LEDs were quickly adopted for use in headlamps due to their smaller size, lower power consumption and improved durability compared with incandescent bulbs.Power LEDs rated 1 watt or more have displaced incandescent bulbs in many models of headlamps. To avoid damage to electronic parts, a heatsink is usually required for headlamps that use LEDs that dissipate more than 1W. To regulate power fed to the LEDs, DC-DC converters are often used, sometimes controlled by microprocessors. This allows the LED(s) to provide brightness that is not affected by a drop in battery voltage, and allows selectable levels of output. Following the introduction of LEDs for headlamps, sometimes combinations of LED and halogen lamps were used, allowing the user to select between the types for various tasks.
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Carbide lamps were developed around 1900, and remained in use even as electric lamps appeared, because of poor battery life of the latter designs. The advent of high-efficiency LED lamps eventually displaced incandescent or combustion lamps.
Thomas Edison developed electric cap lamps for miners starting in 1914; by 1915, certain cap lamps were approved by the United States Bureau of Mines for safe use in gassy coal mines.[ citation needed ] These included features such as spring-loaded contacts to automatically disconnect broken bulbs. These lamps consisted of a reflector and incandescent lamp and a separate belt-mounted wet-cell storage battery.[ citation needed ] The battery was sized to power the lamp for the entire working shift.[ citation needed ] After 12 hours a 1917-era miner's lamp produced less than one candlepower and about 2 to 5 total lumens. This pattern became popular for similar lamps. Head lamps approved for use in coal mines are designed not to allow an internal spark to ignite flammable gas surrounding the headlamp.[ citation needed ]
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An electric light is a device that produces visible light from electric power. It is the most common form of artificial lighting and is essential to modern society, providing interior lighting for buildings and exterior light for evening and nighttime activities. In technical usage, a replaceable component that produces light from electricity is called a lamp. Lamps are commonly called light bulbs; for example, the incandescent light bulb. Lamps usually have a base made of ceramic, metal, glass, or plastic, which secures the lamp in the socket of a light fixture. The electrical connection to the socket may be made with a screw-thread base, two metal pins, two metal caps or a bayonet cap.
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 with a vacuum or inert gas 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.
A halogen lamp is an incandescent lamp consisting of a tungsten filament sealed in a compact transparent envelope that is filled with a mixture of an inert gas and a small amount of a halogen, such as iodine or bromine. The combination of the halogen gas and the tungsten filament produces a halogen-cycle chemical reaction, which redeposits evaporated tungsten on the filament, increasing its life and maintaining the clarity of the envelope. This allows the filament to operate at a higher temperature than a standard incandescent lamp of similar power and operating life; this also produces light with higher luminous efficacy and color temperature. The small size of halogen lamps permits their use in compact optical systems for projectors and illumination. The small glass envelope may be enclosed in a much larger outer glass bulb, which has a lower temperature, protects the inner bulb from contamination, and makes the bulb mechanically more similar to a conventional lamp.
Lighting or illumination is the deliberate use of light to achieve practical or aesthetic effects. Lighting includes the use of both artificial light sources like lamps and light fixtures, as well as natural illumination by capturing daylight. Daylighting is sometimes used as the main source of light during daytime in buildings. This can save energy in place of using artificial lighting, which represents a major component of energy consumption in buildings. Proper lighting can enhance task performance, improve the appearance of an area, or have positive psychological effects on occupants.
A flashlight, (US) or torch is a portable hand-held electric light. Formerly, the light source typically was a miniature incandescent light bulb but these have been displaced by light-emitting diodes (LEDs) since the mid-2000s. A typical flashlight consists of the light source mounted in a reflector, a transparent cover to protect the light source and reflector, a battery, and a switch, all enclosed in a case.
A headlamp is a lamp attached to the front of a vehicle to illuminate the road ahead. Headlamps are also often called headlights, but in the most precise usage, headlamp is the term for the device itself and headlight is the term for the beam of light produced and distributed by the device.
Bicycle lighting is illumination attached to bicycles whose purpose above all is, along with reflectors, to improve the visibility of the bicycle and its rider to other road users under circumstances of poor ambient illumination. A secondary purpose is to illuminate reflective materials such as cat's eyes and traffic signs. A third purpose may be to illuminate the roadway so that the rider can see the way ahead. Serving the latter purposes require much more luminous flux and thus more power.
An emergency light is a battery-backed lighting device that switches on automatically when a building experiences a power outage. Emergency lights are standard in new commercial and high occupancy residential buildings, such as college dormitories, apartments, and hotels. Most building codes require that they be installed in older buildings as well.
Carbide lamps, or acetylene gas lamps, are simple lamps that produce and burn acetylene (C2H2) which is created by the reaction of calcium carbide (CaC2) with water (H2O).
The lighting system of a motor vehicle consists of lighting and signalling devices mounted or integrated at the front, rear, sides, and in some cases the top of a motor vehicle. These light the roadway ahead for the driver and increase the visibility of the vehicle, allowing other drivers and pedestrians to see a vehicle's presence, position, size, direction of travel, and the driver's intentions regarding direction and speed of travel. Emergency vehicles usually carry distinctive lighting equipment to warn drivers and indicate priority of movement in traffic.
A light fixture, light fitting, or luminaire is an electrical device containing an electric lamp that provides illumination. All light fixtures have a fixture body and one or more lamps. The lamps may be in sockets for easy replacement—or, in the case of some LED fixtures, hard-wired in place.
A parabolic aluminized reflector lamp is a type of electric lamp that is widely used in commercial, residential, and transportation illumination. It produces a highly directional beam. Usage includes theatrical lighting, locomotive headlamps, aircraft landing lights, and residential and commercial recessed lights.
Edison screw (ES) is a standard lightbulb socket for electric light bulbs. It was developed by Thomas Edison, patented in 1881, and was licensed in 1909 under General Electric's Mazda trademark. The bulbs have right-hand threaded metal bases (caps) which screw into matching threaded sockets. For bulbs powered by AC current, the thread is generally connected to neutral and the contact on the bottom tip of the base is connected to the "live" phase.
Aircraft warning lights are high-intensity lighting devices attached to tall structures to increase visibility to climbing and descending aircraft. Such devices prevent aircraft from collisions, and are usually used at night, although they may be used during the day. These lights need to be of sufficient brightness to be visible for miles around the structure.
A multifaceted reflector light bulb is a reflector housing format for halogen as well as some LED and fluorescent lamps. MR lamps were originally designed for use in slide projectors, but see use in residential lighting and retail lighting as well. They are suited to applications that require directional lighting such as track lighting, recessed ceiling lights, desk lamps, pendant fixtures, landscape lighting, retail display lighting, and bicycle headlights. MR lamps are designated by symbols such as MR16 where the diameter is represented by numerals indicating units of eighths of an inch. Common sizes for general lighting are MR16 and MR11, with MR20 and MR8 used in specialty applications. Many run on low voltage rather than mains voltage alternating current so require a power supply.
A bipin or bi-pin is a type of lamp fitting. They are included in the IEC standard "IEC 60061 Lamp caps and holders together with gauges for the control of interchangeability and safety". They are used on many small incandescent light bulbs, and for starters on some types of fluorescent lights.
An LED lamp or LED light bulb is an electric light that produces light using light-emitting diodes (LEDs). LED lamps are significantly more energy-efficient than equivalent incandescent lamps and can be significantly more efficient than most fluorescent lamps, The most efficient commercially available LED lamps have efficiencies of 200 lumens per watt (Lm/W). Commercial LED lamps have a lifespan many times longer than incandescent lamps.
A wheat lamp is a type of incandescent light designed for use in underground mining, named for inventor Grant Wheat and manufactured by Koehler Lighting Products in Wilkes-Barre, Pennsylvania, United States, a region known for extensive mining activity.
Holiday lighting technology has been subject to considerable development and variation since the replacement of candles by electric lights. While originally used during the Christmas holidays as Christmas lights, modern electric light arrays have become popular around the world in many cultures and are used both during religious festivals and for other purposes unconnected to any festivities.
A dive light is a light source carried by an underwater diver to illuminate the underwater environment. Scuba divers generally carry self-contained lights, but surface supplied divers may carry lights powered by cable supply.