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Time Switch
A time switch (also called a timer switch, or simply timer) is a device that operates an electric switch controlled by a timer. Intermatic introduced its first time switch in 1945, which was used for "electric signs, store window lighting, apartment hall lights, stokers, and oil and gas burners." A consumer version was added in 1952. The switch may be connected to an electric circuit operating from mains power, including via a relay or contactor; or extra-low voltage, low voltage, including battery (electricity), battery-operated equipment in vehicles. It may be built into power circuits (as with a central heating or water heating, water heater timer), plugged into a AC power plugs and sockets, wall outlet with equipment plugged into the timer instead of directly into the power point; or built into equipment. Types Sleep timer A sleep timer is a function on many modern televisions and other electronic devices that shuts off the power after a preset amount of time. The sett ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clockwork
Clockwork refers to the inner workings of either mechanical devices called clocks and watches (where it is also called the movement (clockwork), movement) or other mechanisms that work similarly, using a series of gears driven by a spring or weight. A clockwork mechanism is often powered by a clockwork motor, description of the clockwork motor in an antique phonograph consisting of a mainspring, a spiral torsion spring of metal ribbon. Energy is stored in the mainspring manually by ''winding it up'', turning a key attached to a ratchet (device), ratchet which twists the mainspring tighter. Then the force of the mainspring turns the clockwork gears, until the stored energy is used up. The adjectives ''wind-up'' and ''spring-powered'' refer to mainspring-powered clockwork devices, which include clocks and watches, kitchen timers, music boxes, and wind-up toys. History The earliest known example of a clockwork set-up is the Antikythera mechanism. This device functioned as a gear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dawn
Dawn is the time that marks the beginning of twilight before sunrise. It is recognized by the diffuse sky radiation, appearance of indirect sunlight being Rayleigh scattering, scattered in Earth's atmosphere, when the centre of the Sun's disc has reached 18° below the observer's horizon. This morning twilight period will last until sunrise (when the Sun's upper limb breaks the horizon), when daylight, direct sunlight outshines the light scattering by particles, diffused light. Etymology "Dawn" derives from the Old English verb , "to become day". Types of dawn Dawn begins with the first sight of lightness in the morning, and continues until the Sun breaks the horizon. The morning twilight is divided in three phases, which are determined by the angular distance of the centre of the Sun (degree (angle), degrees below the horizon) in the morning. These are astronomical, nautical and civil twilight. Astronomical dawn Astronomical dawn begins when the center of the Sun is 18 d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Sensor
Photodetectors, also called photosensors, are devices that detect light or other forms of electromagnetic radiation and convert it into an electrical signal. They are essential in a wide range of applications, from digital imaging and optical communication to scientific research and industrial automation. Photodetectors can be classified by their mechanism of detection, such as the photoelectric effect, photochemical reactions, or thermal effects, or by performance metrics like spectral response. Common types include photodiodes, phototransistors, and photomultiplier tubes, each suited to specific uses. Solar cells, which convert light into electricity, are also a type of photodetector. This article explores the principles behind photodetectors, their various types, applications, and recent advancements in the field. History The development of photodetectors began with the discovery of the photoelectric effect by Heinrich Hertz in 1887, later explained by Albert Einstein i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algorithm
In mathematics and computer science, an algorithm () is a finite sequence of Rigour#Mathematics, mathematically rigorous instructions, typically used to solve a class of specific Computational problem, problems or to perform a computation. Algorithms are used as specifications for performing calculations and data processing. More advanced algorithms can use Conditional (computer programming), conditionals to divert the code execution through various routes (referred to as automated decision-making) and deduce valid inferences (referred to as automated reasoning). In contrast, a Heuristic (computer science), heuristic is an approach to solving problems without well-defined correct or optimal results.David A. Grossman, Ophir Frieder, ''Information Retrieval: Algorithms and Heuristics'', 2nd edition, 2004, For example, although social media recommender systems are commonly called "algorithms", they actually rely on heuristics as there is no truly "correct" recommendation. As an e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Season
A season is a division of the year based on changes in weather, ecology, and the number of daylight hours in a given region. On Earth, seasons are the result of the axial parallelism of Earth's axial tilt, tilted orbit around the Sun. In temperate and polar regions, the seasons are marked by changes in the intensity of sunlight that reaches the Earth's surface, variations of which may cause animals to undergo hibernation or to Migration (ecology), migrate, and plants to be dormant. Various cultures define the number and nature of seasons based on regional variations, and as such there are a number of both modern and historical definitions of the seasons. The Northern Hemisphere experiences most direct sunlight during May, June, and July (thus the traditional celebration of Midsummer in June), as the hemisphere faces the Sun. For the Southern Hemisphere it is instead in November, December, and January. It is Earth's axial tilt that causes the Sun to be higher in the sky during the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coffee
Coffee is a beverage brewed from roasted, ground coffee beans. Darkly colored, bitter, and slightly acidic, coffee has a stimulating effect on humans, primarily due to its caffeine content, but decaffeinated coffee is also commercially available. There are also various coffee substitutes. Typically served hot, coffee has the highest sales in the world market for hot drinks. Coffee production begins when the seeds from coffee cherries (the '' Coffea'' plant's fruits) are separated to produce unroasted green coffee beans. The "beans" are roasted and then ground into fine particles. Coffee is brewed from the ground roasted beans, which are typically steeped in hot water before being filtered out. It is usually served hot, although chilled or iced coffee is common. Coffee can be prepared and presented in a variety of ways (e.g., espresso, French press, caffè latte, or already-brewed canned coffee). Sugar, sugar substitutes, milk, and cream are often added to mask ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morning
Morning is either the period from sunrise to noon, or the period from midnight to noon. In the first definition it is preceded by the twilight period of dawn, and there are no exact times for when morning begins (also true of evening and night) because it can vary according to one's latitude, and the hours of daylight at each time of year. However, morning strictly ends at noon, when afternoon starts. Morning precedes afternoon, evening, and night in the sequence of a day. Originally, the term referred to sunrise. Etymology The Modern English words "morning" and "tomorrow" began in Middle English as , developing into , then , and eventually . English, unlike some other languages, has separate terms for "morning" and "tomorrow", despite their common root. Other languages, like Dutch, Scots and German, may use a single wordto signify both "morning" and "tomorrow". Significance Cultural implications Morning prayer is a common practice in several religions. The morning pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coffee Maker
A coffeemaker, coffee maker or coffee machine is a cooking appliance used to brew coffee. While there are many different types of coffeemakers, the two most common brewing principles use gravity or pressure to move hot water through coffee grounds. In the most common devices, coffee grounds are placed into a paper or metal filter inside a funnel, which is set over a glass or ceramic coffee pot, a cooking pot in the kettle family. Cold water is poured into a separate chamber, which is then boiled and directed into the funnel and allowed to drip through the grounds under gravity. This is also called '' automatic drip-brew''. Coffee makers that use pressure to force water through the coffee grounds are called espresso makers, and they produce espresso coffee. Types Drip coffeemaker The first non-electric drip coffee maker, using notebook paper as the precursor to the paper coffee filter, was developed by German entrepreneur Melitta Bentz in 1908. The same year, she founded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supper
Supper is used commonly as the term for the main evening meal, although its use varies considerably. Supper may be used to describe a snack or light meal in the evening, either after or instead of dinner. Etymology The term is derived from the French ''souper'', which is used for this meal in Canadian French, Swiss French, and in Belgian French. It is related to soup. It is also related to the Scandinavian words for soup, ''soppa'' or S''uppe'', the German word for soup, ''Suppe'' and the Catalan word for soup ''sopa'', in Catalan dinner is also called ''sopar''. The ''Oxford English Dictionary'', however, suggests that the root, sup, remains obscure in origin. History Supper was originally a secondary lighter evening meal. The main meal of the day, called dinner, used to be served closer to what is known as lunchtime, around the middle of the day, but crept later over the centuries, mostly over the course of the 19th century. When dinner was still at the early time, eating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slow Cooker
A slow cooker, (also known as a crock-pot after a trademark owned by Sunbeam Products, but sometimes used generically in the English-speaking world), is a countertop electrical cooking appliance used to simmer at a lower temperature than other cooking methods, such as baking, boiling, and frying. This facilitates unattended cooking for many hours of dishes that would otherwise be boiled: pot roast, soups, stews and other dishes (including beverages, desserts and dips). History Slow cookers achieved popularity in the United States during the 1940s, when many women began to work outside the home. They could start dinner cooking in the morning before going to work and finish preparing the meal in the evening when they came home. The Naxon Utilities Corporation of Chicago, under the leadership of electrical engineer Irving Naxon (born Irving Nachumsohn), developed the Naxon Beanery All-Purpose Cooker for the purposes of cooking a bean meal. Naxon was inspired by a story rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Countdown
A countdown is a sequence of backward counting to indicate the time remaining before an event is scheduled to occur. NASA commonly employs the terms "L-minus" and "T-minus" during the preparation for and anticipation of a rocket launch, and even "E-minus" for events that involve spacecraft that are already in space, where the "T" could stand for "Test" or "Time", and the "E" stands for "Encounter", as with a comet or some other space object, like a spacecraft. Other events for which countdowns are commonly used include the detonation of an explosive, the start of a race, the start of the New Year, or any anxiously anticipated event. An early use of a countdown once signaled the start of a Cambridge University rowing race. One of the first known associations with rockets was in the 1929 German science fiction movie '' Frau im Mond'' (English: ''Woman in the Moon'') written by Thea von Harbou and directed by Fritz Lang in an attempt to increase the drama of the launch sequence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
