82-505: The Redmi Y2 , also referred to as Redmi S2 , is a budget smartphone released by Xiaomi under the sub-brand Redmi in May 2018. It is the successor to Redmi Y1 . Amritanshu Mukherjee from Deccan Chronicle praised the smartphone's battery functions, design, and model, writing overall "Redmi Y2 is a great budget smartphone that ticks all the right boxes and specialises in the optics department. If you are seeking good camera performance fused in
164-524: A capacitor or a rechargeable battery that supplies current to a light source. Such flashlights can be useful during an emergency, when utility power and batteries may not be available. Dynamo-powered flashlights were popular during the Second World War since replacement batteries were difficult to find. At least one manufacturer makes a rechargeable flashlight that uses a supercapacitor to store energy. The capacitor can be recharged more rapidly than
246-407: A high-intensity discharge lamp (HID lamp) as the light source. An HID gas discharge lamp uses a mixture of metal halide salts and noble gas as a filler. HID lamps produce more light than a traditional incandescent flashlight using the same amount of electricity, though not as much as high power LEDs. The lamp lasts longer and is more shock resistant than a regular incandescent bulb, since it lacks
328-484: A 24.7% stake in Roborock. In December 2014, Xiaomi raised US$ 1.1 billion at a valuation of over US$ 45 billion, making it one of the most valuable private technology companies in the world. The financing round was led by Hong Kong-based technology fund All-Stars Investment Limited, a fund run by former Morgan Stanley analyst Richard Ji. In 2014, the company sold over 60 million smartphones. In 2014, 94% of
410-425: A battery and can be recharged many times without loss of capacity; however, the running time is limited by the relative bulk of capacitors compared to electrochemical batteries. A reflector with an approximately parabolic shape concentrates the light emitted by the bulb into a directed beam. Some flashlights allow the user to adjust the relative position of the lamp and reflector, giving a variable-focus effect from
492-410: A case. The invention of the dry cell and miniature incandescent electric lamps made the first battery-powered flashlights possible around 1899. Today, flashlights use mostly light-emitting diodes and run on disposable or rechargeable batteries . Some are powered by the user turning a crank , shaking the lamp, or squeezing it. Some have solar panels to recharge the battery. Flashlights are used as
574-408: A common prefocus-style miniature lamp produces on the order of 15 to 20 lumens of light and a beam of about 200 candlepower . One popular make of rechargeable focusing flashlight uses a halogen lamp and produces 218 lumens. By comparison, a 60-watt household incandescent lamp will produce about 900 lumens. The luminous efficacy or lumens produced per watt of input of flashlight bulbs varies over
656-569: A determining role in the size, weight, run time, and shape of the flashlight. Flashlight users may prefer a common battery type to simplify replacement. Primary cells are most economical for infrequent use. Some types of lithium primary cell can be stored for years with less risk of leakage compared with zinc-type batteries. Long storage life is useful where flashlights are required only in emergencies. Lithium primary batteries are also useful at lower temperatures than zinc batteries, all of which have water-based electrolytes. Lithium primary batteries have
738-410: A flashlight as one of their features, for example, a portable radio/flashlight combination. Many smartphones have a button or software application available to turn up their screen backlights to full intensity or to switch on the camera flash or video light, providing a "flashlight" function. In addition to utilitarian flashlights, novelty, toy, and ornamental portable electric lights have been made in
820-535: A hand-held light source and magnifying lenses for examination of the ear canal and eyes, respectively. Aboard naval ships, battle lanterns may be used as emergency portable lighting. Installed in major compartments of the ship, a battle lantern can be detached from its mounting and used as portable lighting in the event primary lighting is out of service. Battle lanterns may use either incandescent or LED lamps and may have either disposable primary or rechargeable batteries. Many flashlights are cylindrical in design, with
902-442: A lamp mounted at the end of a flexible cable, or a semirigid or articulated probe. Such lamps are used for inspection inside tanks, or inside structures such as aircraft. Where used for inspecting the interior of tanks containing flammable liquids, the inspection lights may also be rated as flame-proof (explosion-proof) so that they cannot ignite liquids or vapors. Otoscopes and ophthalmoscopes are medical instruments that combine
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#1732869491661984-489: A light source outdoors, in places without permanently installed lighting, during power outages , or when a portable light source is needed. In addition to the general-purpose, hand-held flashlight, many forms have been adapted for special uses. Head- or helmet-mounted flashlights designed for miners and campers leave both hands free. Some flashlights can be used under water or in flammable atmospheres. Early flashlights ran on zinc–carbon batteries , which could not provide
1066-472: A lower internal resistance than zinc primary batteries, so are more efficient in high-drain flashlights. Flashlights used for extended periods every day may be more economically operated on rechargeable (secondary) batteries. Flashlights designed for rechargeable batteries may allow charging without removing the batteries; for example, a light kept in a vehicle may be trickle-charged and always ready when needed. Some rechargeable flashlights have indicators for
1148-434: A metal body, similar hardware specifications but a bigger 4,000mAh battery". The smartphone was also reviewed by Shruti Dhapola of The Indian Express , Mike Wobker of Notebookcheck , and by Hindustan Times . This mobile phone related article is a stub . You can help Misplaced Pages by expanding it . Xiaomi Xiaomi Corporation ( / ˈ ʃ aʊ m i / ; Chinese : 小米 集团 ), commonly known as Xiaomi ,
1230-617: A mid-range smartphone line, first launching in India. In Q4 of 2018, the Xiaomi Pocophone F1 became the best-selling smartphone sold online in India. The Pocophone was sometimes referred to as the "flagship killer" for offering high-end specifications at an affordable price. The company opened new headquarters in Beijing in July 2019 after almost four years of construction. In October 2019,
1312-550: A myriad of shapes; in the 1890s, one of the earliest portable battery light applications was a type of novelty porcelain tie pin with a concealed bulb and battery. The most common power source for flashlights is the battery. Primary battery ( disposable ) types used in flashlights include button cells , carbon-zinc batteries in both regular and heavy duty types, alkaline , and lithium . Secondary, rechargeable types include lead-acid batteries , NiMH , NiCd batteries and lithium-ion batteries . The choice of batteries plays
1394-399: A package that is overall a great daily driver, then look no further." Ehsanur Raza Ronny from The Daily Star rated the smartphone a 6.75, stating "Xiaomi has made an excellent budget device which is jam-packed with good features." Sudhanshu Singh from TechRadar rated the smartphone 3.5 out of 5 stars, praising the smartphone's front camera features and its build, but also stating that it
1476-447: A paste electrolyte instead of a liquid. This was the first battery suitable for portable electrical devices, as it did not spill or break easily and worked in any orientation. The first mass-produced dry cell batteries came in 1896, and the invention of portable electric lights soon followed. Portable hand-held electric lights offered advantages in convenience and safety over (combustion) torches , candles and lanterns . The electric lamp
1558-406: A plastic or glass "bulls-eye" lens to form a concentrated beam. The lens or reflector cover must resist impacts and the heat of the lamp, and must not lose too much of the transmitted light to reflection or absorption. Very small flashlights may not have a reflector or lens separate from the lamp. Some types of penlight bulbs or small LEDs have a built-in lens. A reflector forms a narrow beam called
1640-623: A selfie smartphone in the budget segment". Saurabh Singh of India Today wrote that the Redimi Y2 was "better, nay, way better than the Redmi Y1", while Karan Bajaj of The Economic Times wrote "In our opinion, the Redmi Y2 proves to be a great all-rounder smartphone for its price", but also wrote that the troubling factor was "at the same price you also have the option of the Redmi Note 5 . The Note 5 has
1722-438: A single 5 mm LED, may only produce a few lumens. Even a small LED flashlight operating on an AA cell, but equipped with an LED, can emit 100 lumens. The most powerful LED flashlights produce more than 100,000 lumens and may use multiple LEDs. LEDs are highly efficient at producing colored light compared with incandescent lamps and filters. An LED flashlight may contain different LEDs for white and colored light, selectable by
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#17328694916611804-536: A smartphone gaming brand called Black Shark. It had 6GB of RAM coupled with Snapdragon 845 SoC, and was priced at $ 508, which was cheaper than its competitors. On 2 May 2018, Xiaomi announced the launch of Mi Music and Mi Video to offer "value-added internet services" in India. On 3 May 2018, Xiaomi announced a partnership with 3 to sell smartphones in the United Kingdom, Ireland, Austria, Denmark, and Sweden In May 2018, Xiaomi began selling smart home products in
1886-399: A steady electric current and required periodic "rest" to continue functioning. Because these early flashlights also used energy-inefficient carbon-filament bulbs, "resting" occurred at short intervals. Consequently, they could be used only in brief flashes, hence the common North American name "flashlight". The first dry cell battery was invented in 1887. Unlike previous batteries, it used
1968-407: A target. They are small enough to be easily rail-mounted to a gun barrel. Tactical lights must withstand the impact of recoil and must be easily controlled while holding the weapon. Although most flashlights are designed for user replacement of the batteries and the bulb as needed, fully sealed disposable flashlights, such as inexpensive keyring lights, are made. When the batteries are depleted or
2050-467: A transparent optical element (light pipe) to guide light from the source into a beam; no reflector surface is required. For a given size of light source, a larger reflector or lens allows a tighter beam to be produced, while capturing the same fraction of the emitted light. Some flashlights use Fresnel lenses , which allow the weight of the lens to be reduced. The reflector may have a flat transparent cover to keep out dirt and moisture, but some designs have
2132-423: A tubular shape, or tubular extruded stock can be machined to add threads for the head and tail cap, knurling for grip, and decorative and functional flats or holes in the body. LED flashlights may have cooling fins machined into their metal cases. Plastics are often injection molded into nearly final shape, requiring only a few more process steps to complete assembly. Metal cases provide better heat dissipation for
2214-471: A white LED, which needs around 3.4 volts to function. Flashlights using three or more dry cells may only use a resistor to limit current. Some flashlights electronically regulate the current through the LEDs to stabilize light output as the batteries discharge. LEDs maintain nearly constant color temperature regardless of input voltage or current, while the color temperature of an incandescent bulb rapidly declines as
2296-415: A wide floodlight to a narrow beam. Reflectors may be made of polished metal, glass, or plastic with an aluminized reflective finish. Some manufacturers use a pebbled or "orange peel", instead of a smooth reflector, to improve the uniformity of the light beam emitted. Where multiple LEDs are used, each one may be put in its own parabolic reflector. Flashlights using a " total internal reflection " assembly have
2378-409: A winding crank and spring connected to a small electrical generator (dynamo). Some types use the dynamo to charge a capacitor or battery, while others only light while the dynamo is moving. Others generate electricity using electromagnetic induction . They use a strong permanent magnet that can freely slide up and down a tube, passing through a coil of wire as it does. Shaking the flashlight charges
2460-463: Is a Chinese designer and manufacturer of consumer electronics and related software, home appliances , automobiles and household hardware , with headquarters in Beijing, China. It is the second-largest manufacturer of smartphones in the world, behind Samsung , most of which run on the Xiaomi HyperOS (former MIUI ) operating system . The company is ranked 338th and is the youngest company on
2542-422: Is a portable hand-held electric lamp. Formerly, the light source typically was a miniature incandescent light bulb , but these have been displaced by light-emitting diodes (LEDs) since the early 2000s. A typical flashlight consists of the light source mounted in a reflector, a transparent cover (sometimes combined with a lens ) to protect the light source and reflector, a battery , and a switch , all enclosed in
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2624-526: Is a slide switch that allows the light to be left on for an extended time, combined with a momentary button for intermittent use or signalling. (On earlier models, the button was a switch and the slider simply locked the button down.) Since voltages and currents are low, switch design is limited only by the available space and desired cost of production. Switches may be covered with a flexible rubber boot to exclude dirt and moisture and may be backlit for easy location. Another common type of switch relies on twisting
2706-443: Is designed to be worn on the head, often having separate lamp and battery components. The battery pack may be attached at the back of the head or in a pocket to improve balance. Headlamps leave the users' hands' free. A headlamp can be clipped to the brim of a hat, or built to mount on a hard hat , instead of using straps; other types resemble eyeglass frames. Similar to the headlamp, an angle-head flashlight emits light perpendicular to
2788-579: The Fortune Global 500 . Xiaomi was founded in 2010 in Beijing by Lei Jun along with six associates. Lei had founded Kingsoft as well as Joyo.com , the latter of which he sold to Amazon for $ 75 million in 2004. In August 2011, Xiaomi released its first smartphone and, by 2014, it had the largest market share of smartphones sold in China. Initially the company only sold its products online; however, it later opened brick and mortar stores. By 2015, it
2870-571: The Android platform. He was employed as vice president of Xiaomi to expand the company outside of mainland China, making Xiaomi the first company selling smartphones to poach a senior staffer from Google's Android team. He left the company in February 2017. In September 2013, Xiaomi announced its Xiaomi Mi 3 smartphone and an Android-based 47-inch 3D-capable Smart TV assembled by Sony TV manufacturer Wistron of Taiwan. In October 2013, it became
2952-711: The European Union (EU) through a partnership with ABC Data. Also in September 2016, the Xiaomi Mi Robot vacuum was released by Roborock. On 26 October 2016, Xiaomi launched the Mi Mix, powered by the Qualcomm Snapdragon 821 processor. On 22 March 2017, Xiaomi announced that it planned to set up a second manufacturing unit in India in partnership with contract manufacturer Foxconn. On 19 April 2017, Xiaomi launched
3034-411: The " Apple of China". It has come up with its own range of wearable items. It also is a major manufacturer of appliances including televisions, flashlights , unmanned aerial vehicles , and air purifiers using its Internet of things and Xiaomi Smart Home product ecosystems. Xiaomi keeps its prices close to its manufacturing costs and bill of materials costs by keeping most of its products in
3116-463: The "throw" in hobbyist parlance, while light emitted forward misses the reflector and forms a wide flood or "spill" of light. Because LEDs emit most light in a hemisphere, lens lights with the LED facing forward or reflector lights with it facing backwards radiate less spill. Variable focus "zoom" or "flood to throw" lights may move the reflector or lens or they may move the emitter; moving the emitter presents
3198-413: The LED has a long life compared to the usual life of a flashlight, very often it is permanently installed. Flashlights made for an incandescent lamp can often be upgraded to a more efficient LED lamp. LEDs generally must have some kind of control to limit current through the diode. Flashlights using one or two disposable 1.5-volt cells require a boost converter to provide the higher voltage required by
3280-420: The LED, but plastics are not electrically conductive and may resist corrosion and wear. Industrial, marine, public safety, and military organizations develop specifications for flashlights in specialized roles. Typically, light output, overall dimensions, and battery compatibility and durability are required to meet minimum limits. Flashlights may be tested for impact resistance, water and chemical resistance, and
3362-572: The Luxeon LED, a high-power white-light emitter. This made possible LED flashlights with lower power consumption and running time better than incandescent flashlights with similar light output. The first Luxeon LED flashlight was the Arc LS, designed in 2001. White LEDs in 5 mm diameter packages produce only a few lumens each; many units may be grouped together to provide additional light. Higher-power LEDs, drawing more than 100 milliamperes each, simplify
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3444-673: The Mi Mix Fold. Powered by Qualcomm Snapdragon 888 with an 8.01-inch foldable AMOLED display when open and a 6.5-inch external display when folded. In March 2020, Xiaomi showcased its new 40W wireless charging solution, which was able to fully charge a smartphone with a 4,000mAh battery from flat in 40 minutes. In October 2020, Xiaomi became the third-largest smartphone maker in the world by shipment volume, shipping 46.2 million handsets in Q3 2020. On 30 March 2021, Xiaomi announced its intention to invest US$ 10 billion in electric vehicles over
3526-574: The Mi5, powered by the Qualcomm Snapdragon 820 processor. On 3 March 2016, Xiaomi launched the Redmi Note 3 Pro in India, the first smartphone to be powered by a Qualcomm Snapdragon 650 processor. On 10 May 2016, Xiaomi launched the Mi Max, powered by the Qualcomm Snapdragon 650/652 processor. In June 2016, the company acquired patents from Microsoft . In September 2016, Xiaomi launched sales in
3608-516: The Mi6, powered by the Qualcomm Snapdragon 835 processor. In July 2017, the company entered into a patent licensing agreement with Nokia . On 5 September 2017, Xiaomi released Xiaomi Mi A1 , the first Android One smartphone under the slogan: Created by Xiaomi, Powered by Google. Xiaomi stated started working with Google for the Mi A1 Android One smartphone earlier in 2017. An alternate version of
3690-550: The United States through Amazon . In June 2018, Xiaomi became a public company via an initial public offering on the Hong Kong Stock Exchange , raising $ 4.72 billion. On 7 August 2018, Xiaomi announced that Holitech Technology Co. Ltd., Xiaomi's top supplier, would invest up to $ 200 million over the next three years to set up a major new plant in India. In August 2018, the company announced POCO as
3772-426: The United States, with annual sales of renewal batteries and flashlights at $ 20 million, comparable to sales of many line-operated electrical appliances. Flashlights became very popular in China; by the end of the 1930s, 60 companies made flashlights, some selling for as little as one-third the cost of equivalent imported models. Miniature lamps developed for flashlight and automotive uses became an important sector of
3854-453: The absence of flame, meant that hand-held electric lights began to replace combustion-based lamps such as the hurricane lantern . By 1907, several types of flashlights were available: the tubular hand-held variety, a lantern style that could be set down for extended use, pocket-size penlights for close work, and large reflector searchlight-type lamps for lighting distant objects. In 1922 there were an estimated 10 million flashlight users in
3936-412: The approximate range of 8 to 22 lumens/watt, depending on the size of the bulb and the fill gas, with halogen-filled 12-volt lamps having the highest efficiency. Powerful white- light-emitting diodes (LEDs) have mostly replaced incandescent bulbs in practical flashlights. LEDs existed for decades, mainly as low-power indicator lights. In 1999, Lumileds Corporation of San Jose, California , introduced
4018-410: The battery discharges, becoming redder and less visible. Regulated LED flashlights may also have user-selectable levels of output appropriate to a task, for example, low light for reading a map and high output for checking a road sign. This would be difficult to do with a single incandescent bulb since efficacy of the lamp drops rapidly at low output. LED flashlights may consume 1 watt or much more from
4100-575: The battery, producing heat as well as light. In contrast to tungsten filaments, which must be hot to produce light, both the light output and the life of an LED decrease with temperature. Heat dissipation for the LED often dictates that small, high-power LED flashlights have aluminium or other high heat-conductivity bodies, reflectors, and other parts to dissipate heat; they can become warm during use. Light output from LED flashlights varies even more widely than for incandescent lights. "Keychain" type lamps operating on button batteries , or lights using
4182-413: The bulb contains a halogen gas such as iodine or bromine to improve the life and efficacy of the bulb. In all but disposable or novelty flashlights, the bulb is user-replaceable; the bulb life may be only a few hours. The light output of an incandescent lamp in a flashlight varies widely depending on the type of lamp. A miniature keychain lamp produces one or two lumens. A two-D-cell flashlight using
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#17328694916614264-628: The bulb fails, the entire product is discarded. Diving lamps must be watertight under pressure and are used for night diving and supplemental illumination where surface light cannot reach. The battery compartment of a dive lamp may have a catalyst to recombine any hydrogen gas emitted from the battery since gas cannot be vented in use. People working in hazardous areas with significant concentrations of flammable gases or dusts, such as mines, engine rooms of ships, chemical plants, or grain elevators , use "nonincendive", "intrinsically safe", or "explosion-proof" flashlights constructed so that any spark in
4346-644: The company announced that it would launch more than 10 5G phones in 2020, including the Mi 10/10 Pro with 5G functionality. On 5 November 2019, Xiaomi announced that it would enter the Japanese market. It established a subsidiary, Xiaomi Japan, as parts of its effort to enter the Japanese smartphone market. On 17 January 2020, POCO India became a separate sub-brand of Xiaomi with entry-level and mid-range devices, followed by its global counterpart on 24 November 2020. In March 2020, Xiaomi launched their first foldable phone,
4428-451: The company raised $ 90 million in a Series B round. In June 2012, the company raised $ 216 million of funding in a Series C round at a $ 4 billion valuation. Institutional investors participating in the first round of funding included Temasek Holdings , IDG Capital , Qiming Venture Partners and Qualcomm . In August 2013, the company hired Hugo Barra from Google, where he served as vice president of product management for
4510-454: The company's revenue came from mobile phone sales. In April 2015, Ratan Tata acquired a stake in Xiaomi. On 30 June 2015, Xiaomi announced its expansion into Brazil with the launch of locally manufactured Redmi 2; it was the first time the company assembled a smartphone outside of China. However, the company left Brazil in the second half of 2016. On 26 February 2016, Xiaomi launched
4592-486: The designer with the problem of maintaining heat dissipation for the LED. The original 1890s flashlights used a metal ring around the fiber body of the flashlight as one contact of a switch ; the second contact was a movable metal loop that could be flipped down to touch the ring, completing the circuit. A wide variety of mechanical switch designs using slide switches, rocker switches, or side-mounted or end-mounted pushbuttons has been used in flashlights. A common combination
4674-509: The fifth-most-used smartphone brand in China. In 2013, Xiaomi sold 18.7 million smartphones. In February 2014, Xiaomi announced its expansion outside China, with an international headquarters in Singapore. In April 2014, Xiaomi purchased the domain name mi.com for a record US$ 3.6 million , the most expensive domain name ever bought in China, replacing xiaomi.com as the company's main domain name. In September 2014, Xiaomi acquired
4756-546: The finished flashlight case. Aluminum, either plain, painted or anodized , is a popular choice. It is electrically conductive, can be easily machined, and dissipates heat well. Several standard alloys of aluminum are used. Other metals include copper , stainless steel , and titanium , which can be polished to provide a decorative finish. Zinc can be die-cast into intricate shapes. Magnesium and its alloys provide strength and heat dissipation similar to aluminum with less weight, but they corrode easily. Metals may be drawn into
4838-439: The first LEP flashlight available in 2018, there are currently a few dozen LEP flashlights, mainly from China. At the moment, there are 2 types of LEP modules used. The laser light either shines through the phosphor layer to produce white light, or is directed at the layer by a mirror. The mirror-type is built inside a plastic module, while the shine-through models are usually built with a copper/aluminum shell, and much smaller than
4920-615: The flashlight are used for signalling, for example, in railway yards. Colored light is occasionally useful for hunters tracking wounded game after dusk, or for forensic examination of an area. A red filter helps preserve night vision after the flashlight is turned off, and can be useful to observe animals (such as nesting loggerhead sea turtles ) without disturbing them. Detachable light guides, consisting of rigid, bent plastic rods or semirigid or flexible tubes containing optical fibers, are available for some flashlights for inspection inside tanks, or within walls or structures; when not required,
5002-490: The flashlight is not likely to set off an explosion outside the light. The flashlight may require approval by an authority for the particular service and particular gases or dusts expected. The external temperature rise of the flashlight must not exceed the autoignition point of the gas, so substitution of more powerful lamps or batteries may void the approval. Inspection flashlights have permanently mounted light guides containing optical fibers or plastic rods. Another style has
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#17328694916615084-618: The following ten years. On 31 March 2021, Xiaomi announced a new logo for the company, designed by Kenya Hara . In July 2021, Xiaomi became the second largest smartphone maker in the world, according to Canalys. It also surpassed Apple for the first time in Europe, making it the second-largest in Europe according to Counterpoint. In August 2021, the company acquired autonomous driving company Deepmotion for $ 77 million. Flashlight A flashlight ( US English ) or electric torch ( Commonwealth English ), usually shortened to torch,
5166-501: The head of the light. Weapon-mounted lights may have remote switches for convenience in operation. Electronic controls allow the user to select variable output levels or different operating modes such as pre-programmed flashing beacon or strobe modes. Electronic controls may be operated by buttons, sliders, magnets, rotating heads, or rotating control rings. Some models of flashlight include an acceleration sensor to allow them to respond to shaking, or to select modes based on what direction
5248-409: The incandescent lamp manufacturing business. LED flashlights were introduced in the early 2000s. Maglite made their first LED flashlight in 2006. Incandescent flashlights use incandescent light bulbs, which consists of a glass bulb and a tungsten filament. The bulbs are under vacuum or filled with argon , krypton , or xenon . Some high-power incandescent flashlights use a halogen lamp where
5330-406: The lamp assembly attached to one end. However, early designs came in a variety of other shapes. Some resembled candlesticks , with a bulb mounted at the top of a battery tube fixed to a flat base, with a handle. Many resembled lanterns , consisting of a battery box with a handle and the lamp and reflector attached to the front. Electric lanterns are used for lighting the broad area immediately around
5412-421: The lantern, as opposed to forming a narrow beam; they can be set down on a level surface or attached to supports. Some electric lanterns use miniature fluorescent lamps for higher efficiency than incandescent bulbs. Portable hand-held electric spotlights can provide larger reflectors and lamps and more powerful batteries than tubular flashlights meant to fit in a pocket. Multifunction portable devices may include
5494-403: The length of the battery tube; it can be clipped to a headband, belt, or webbing or set on a flat surface. Some types allow the user to adjust the angle of the head. The Fulton MX991/U Flashlight was an angle-head flashlight issued to US military personnel; similar style lights remain popular. Tactical lights are sometimes mounted to a handgun or rifle . They allow momentary illumination of
5576-413: The lifespan of the control switch. Flashlights intended for use in hazardous areas with flammable gas or dust are tested to ensure they cannot set off an explosion. Flashlights approved for flammable gas areas have markings indicating the approving agency ( MSHA , ATEX , UL , etc.) and symbols for the conditions that were tested. Flashlights for hazardous areas may be designed to automatically disconnect
5658-600: The light bulb and a rough brass reflector at the end. The company donated some of these devices to the New York City police , who responded favorably to them. Carbon-filament bulbs and fairly crude dry cells made early flashlights an expensive novelty, with low sales and low manufacturer interest. Development of the tungsten-filament lamp in 1904, with three times the efficacy of carbon filament types, along with improved batteries in varying sizes made flashlights more useful and popular. The advantage of instant control, and
5740-566: The light guide can be removed and the light used for other purposes. A penlight is a small, pen -sized flashlight, often containing two AA or AAA batteries . In some types, the incandescent light bulb has an integral lens that focuses the light, so no reflector is built into the penlight. Others use incandescent bulbs mounted in reflectors. LED penlights are becoming increasingly common. Low-cost units may be disposable with no provision to replace batteries or bulbs and are sometimes imprinted with advertising for promotional purposes. A headlamp
5822-940: The light is held when switched on. At least one manufacturer allows user programming of the features of the flashlight through a USB port. An electronic control may also provide an indication of remaining battery capacity, voltage, or provide information regarding recharging or automatic step-down of brightness as the battery nears full discharge. Early flashlights used vulcanized fiber or hard rubber tubes with metal end caps. Many other materials including drawn steel, plated brass, copper, or silver, and even wood and leather have been used. Modern flashlights are generally made of plastic or aluminum. Plastics range from low-cost polystyrene and polyethylene to more complex mixtures of ABS or glass-reinforced epoxies. Some manufacturers have proprietary plastic formulations for their products. A desirable plastic for manufacturing flashlights allows for ease of molding and adequate mechanical properties of
5904-420: The market for 18 months, longer than most smartphone companies. The company also uses inventory optimization and flash sales to keep its inventory low. On 6 April 2010 Xiaomi was co-founded by Lei Jun and six others: Lei had founded Kingsoft as well as Joyo.com, the latter of which he sold to Amazon for $ 75 million in 2004. At the time of the founding of the company, Lei was dissatisfied with
5986-593: The optical design problem of producing a powerful and tightly controlled beam. LEDs can be significantly more efficient than incandescent lamps , with white LEDs producing on the order of 100 lumens for every watt, compared to 8-10 lumens per watt of small incandescent bulbs. An LED flashlight has a longer battery life than an incandescent flashlight with comparable output. LEDs are also less fragile than glass lamps. LED lamps have different spectra of light compared to incandescent sources, and are made in several ranges of color temperature and color rendering index . Since
6068-633: The phone was also available with MIUI, the MI 5X. In 2017, Xiaomi opened Mi Stores in India, Pakistan and Bangladesh. The EU's first Mi Store was opened in Athens , Greece in October 2017. In Q3 2017, Xiaomi overtook Samsung to become the largest smartphone brand in India. Xiaomi sold 9.2 million units during the quarter. On 7 November 2017, Xiaomi commenced sales in Spain and western Europe. In April 2018, Xiaomi announced
6150-402: The plastic type. Accessories for a flashlight allow the color of the light to be altered or allow light to be dispersed differently. Translucent colored plastic cones slipped over the lens of a flashlight increase the visibility when looking at the side of the light. Such marshalling wands are frequently used for directing automobiles or aircraft at night. Colored lenses placed over the end of
6232-486: The products of other mobile phone manufacturers and thought he could make a better product. On 16 August 2010, Xiaomi launched its first Android -based firmware MIUI (Now Xiaomi HyperOS ). In 2010, the company raised $ 41 million in a Series A round . In August 2011, the company launched its first phone, the Xiaomi Mi 1 . The device had Xiaomi's MIUI firmware along with Android installation. In December 2011,
6314-415: The relatively fragile electrical filament found in incandescent bulbs. However, they are much more expensive than incandescent, due to the ballast circuit required to start and operate the lamp. An HID lamp requires a short warm-up time before it reaches full output. LEP stands for Laser Excited Phosphor. The light source is a blue laser diode, which is directed at a phosphor layer to make white light. With
6396-422: The state of charge of the battery. Power-failure lights are designed to keep their batteries charged from a wall plug and to automatically turn on after an AC power failure; the power-failure light can be removed from the wall socket and used as a portable flashlight. Solar powered flashlights use energy from solar cells to charge an on-board battery for later use. One type of mechanically powered flashlight has
6478-697: The user for different purposes. Colored LED flashlights are used for signalling, special inspection tasks, forensic examination, or to track the blood trail of wounded game animals. A flashlight may have a red LED intended to preserve dark adaptation of vision. Ultraviolet LEDs may be used for inspection lights, for example, detecting fluorescent dyes added to air conditioning systems to detect leakage, examining paper currency , or checking UV-fluorescing marks on laundry or event ticket holders. Infrared LEDs can be used for illuminators for night-vision systems. LED flashlights may be specified to be compatible with night vision devices . A less common type of flashlight uses
6560-422: Was "slightly bulky" and its poor handling with one hand. Subhrojit Mallick of Digit wrote "The Redmi Y2 doesn’t bring anything groundbreaking to the table. It's bland, but functional", blaming the smartphone for its image quality and battery life, but described its design as "predictable, but reliable". Khalid Anzar of Business Standard wrote the overall performance of the smartphone as a "great proposition as
6642-399: Was developing a wide range of consumer electronics. In 2020, the company sold 149.4 million smartphones and its MIUI (now Xiaomi HyperOS) mobile operating system has over 500 million monthly active users. As of August 2024, Xiaomi is the second-largest seller of smartphones worldwide, with a market share of about 12%, according to Counterpoint. Its presence led some people to call Xiaomi
6724-416: Was odorless, smokeless, and emitted less heat than combustion-powered lighting. It could be instantly turned on and off, and avoided fire risk. On January 10, 1899, British inventor David Misell obtained U.S. Patent No. 617,592, assigned to American Electrical Novelty and Manufacturing Company . This "electric device" designed by Misell was powered by "D" batteries laid front to back in a paper tube with
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