|
Siderostat
A heliostat () is a device that reflects sunlight toward a target, turning to compensate for the Sun's apparent motion. The reflector is usually a plane mirror. The target may be a physical object, distant from the heliostat, or a direction in space. To do this, the reflective surface of the mirror is kept perpendicular to the bisector of the angle between the directions of the Sun and the target as seen from the mirror. In almost every case, the target is stationary relative to the heliostat, so the light is reflected in a fixed direction. According to contemporary sources the heliostata, as it was called at first, was invented by Willem 's Gravesande (1688–1742). Other contenders are Giovanni Alfonso Borelli (1608–1679) and Daniel Gabriel Fahrenheit (1686–1736). A heliostat designed by George Johnstone Storey is in the Science Museum Group collection. Currently, most heliostats are used for daylighting or for the production of concentrated solar power, usually t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heliostat
A heliostat () is a device that reflects sunlight toward a target, turning to compensate for the Sun's apparent motion. The reflector is usually a plane mirror. The target may be a physical object, distant from the heliostat, or a direction in space. To do this, the reflective surface of the mirror is kept perpendicular to the bisector of the angle between the directions of the Sun and the target as seen from the mirror. In almost every case, the target is stationary relative to the heliostat, so the light is reflected in a fixed direction. According to contemporary sources the heliostata, as it was called at first, was invented by Willem 's Gravesande (1688–1742). Other contenders are Giovanni Alfonso Borelli (1608–1679) and Daniel Gabriel Fahrenheit (1686–1736). A heliostat designed by George Johnstone Storey is in the Science Museum Group collection. Currently, most heliostats are used for daylighting or for the production of concentrated solar power, us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Solar Project
The SOLAR Project consists of the Solar One, Solar Two and Solar Tres solar thermal power plants based in the Mojave Desert, United States and Andalucía, Spain. The US Department of Energy (DOE) and a consortium of US utilities built the country's first two large-scale, demonstration solar power towers in the desert near Barstow, California. Solar One/Solar Two have been scrapped since 2009. Solar Tres (later renamed Gemasolar), the first commercial plant of the project, was opened in Spain in 2011. Solar One Solar One was a pilot solar-thermal project built in the Mojave Desert just east of Barstow, CA, USA. It was the first test of a large-scale thermal solar power tower plant. Solar One was designed by the Department of Energy (DOE) (led by Sandia National Laboratories in Livermore, California), Southern California Edison, LA Dept of Water and Power, and California Energy Commission. It was located in Daggett, CA, about east of Barstow. Solar One's method o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star
A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sky, night; their immense distances from Earth make them appear as fixed stars, fixed points of light. The most prominent stars have been categorised into constellations and asterism (astronomy), asterisms, and many of the brightest stars have proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. The observable universe contains an estimated to stars. Only about 4,000 of these stars are visible to the naked eye—all within the Milky Way galaxy. A star's life star formation, begins with the gravitational collapse of a gaseous nebula of material largely comprising hydrogen, helium, and traces of heavier elements. Its stellar mass, total mass mainly determines it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Tracker
A solar tracker is a device that orients a payload toward the Sun. Payloads are usually solar panels, parabolic troughs, Compact linear Fresnel reflector, Fresnel reflectors, lens (optics), lenses, or the mirrors of a heliostat. For flat-panel photovoltaic systems, trackers are used to minimize the angle of incidence (optics), angle of incidence between the incoming sunlight and a photovoltaic panel, sometimes known as the cosine error. Reducing this angle increases the amount of energy produced from a fixed amount of installed power-generating capacity. In standard photovoltaic applications, it was predicted in 2008–2009 that trackers could be used in at least 85% of commercial installations greater than one megawatt from 2009 to 2012. As the pricing, reliability, and performance of single-axis trackers have improved, the systems have been installed in an increasing percentage of utility-scale projects. According to data from WoodMackenzie/GTM Research, global solar tracke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensors
A sensor is often defined as a device that receives and responds to a signal or stimulus. The stimulus is the quantity, property, or condition that is sensed and converted into electrical signal. In the broadest definition, a sensor is a device, module, machine, or subsystem that detects events or changes in its environment and sends the information to other electronics, frequently a computer processor. Sensors are used in everyday objects such as touch-sensitive elevator buttons ( tactile sensor) and lamps which dim or brighten by touching the base, and in innumerable applications of which most people are never aware. With advances in micromachinery and easy-to-use microcontroller platforms, the uses of sensors have expanded beyond the traditional fields of temperature, pressure and flow measurement, for example into MARG sensors. Analog sensors such as potentiometers and force-sensing resistors are still widely used. Their applications include manufacturing and machiner ... [...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] |
Stepper Motor
A stepper motor, also known as step motor or stepping motor,Clarence W. de Silva. Mechatronics: An Integrated Approach (2005). CRC Press. p. 675. "The terms ''stepper motor'', ''stepping motor'', and ''step motor'' are synonymous and are often used interchangeably." is a brushless DC electric motor that rotates in a series of small and discrete angular steps. Stepper motors can be set to any given step position without needing a Rotary encoder, position sensor for feedback. The step position can be rapidly increased or decreased to create continuous rotation, or the motor can be ordered to actively hold its position at one given step. Motors vary in size, speed, step resolution, and torque. Switched reluctance motors are very large stepping motors with a reduced pole count. They generally employ closed-loop commutator (electric), commutators. Mechanism Brushed DC motors rotate continuously when DC voltage is applied to their terminals. The stepper motor is known for its proper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Motor
An electric motor is a machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a electromagnetic coil, wire winding to generate Laplace force in the form of torque applied on the motor's shaft. An electric generator is mechanically identical to an electric motor, but operates in reverse, converting mechanical energy into electrical energy. Electric motors can be powered by direct current (DC) sources, such as from batteries or rectifiers, or by alternating current (AC) sources, such as a power grid, Inverter (electrical), inverters or electrical generators. Electric motors may also be classified by considerations such as power source type, construction, application and type of motion output. They can be brushed motor, brushed or brushless motor, brushless, single-phase electric power, single-phase, two-phase electric power, two-phase, or three-phase electric p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical
Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, meteoroids, asteroids, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Egyptians, Babylonians, Greeks, Indians, Chinese, Maya, and many ancient indigenous peoples of the Americas. In the past, astronomy included disciplines as diverse as astrometry, celestial naviga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longitude
Longitude (, ) is a geographic coordinate that specifies the east- west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek letter lambda (λ). Meridians are imaginary semicircular lines running from pole to pole that connect points with the same longitude. The prime meridian defines 0° longitude; by convention the International Reference Meridian for the Earth passes near the Royal Observatory in Greenwich, south-east London on the island of Great Britain. Positive longitudes are east of the prime meridian, and negative ones are west. Because of the Earth's rotation, there is a close connection between longitude and time measurement. Scientifically precise local time varies with longitude: a difference of 15° longitude corresponds to a one-hour difference in local time, due to the differing position in relation to the Sun. Comparing local time to an absol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latitude
In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at the south pole to 90° at the north pole, with 0° at the Equator. Parallel (latitude), Lines of constant latitude, or ''parallels'', run east-west as circles parallel to the equator. Latitude and longitude are used together as a coordinate pair to specify a location on the surface of the Earth. On its own, the term "latitude" normally refers to the ''geodetic latitude'' as defined below. Briefly, the geodetic latitude of a point is the angle formed between the vector perpendicular (or ''Normal (geometry), normal'') to the ellipsoidal surface from the point, and the equatorial plane, plane of the equator. Background Two levels of abstraction are employed in the definitions of latitude and longitude. In the first step the physical surface i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
