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Levitron
Levitron is a brand of levitating toys and gifts in science and educational markets marketed by Creative Gifts Inc. and Fascination Toys & Gifts. The ''Levitron'' top device is a commercial toy under this brand that displays the phenomenon known as spin-stabilized magnetic levitation. This method, with moving permanent magnets, is quite distinct from other versions which use changing electromagnetic fields, levitating various items such as a rotating world globe, model space shuttle or VW Beetle, and picture frame. 750,000 units of the top were sold from 1994 through 1999. The top device The toy top is essentially a permanent magnetic ring and corresponding magnetic base plate with a ring or alternate geometric configuration. Functional parameters, such as the top rotation rate or top weighting, are stringent. Employing principles of the magnetic field and gyroscopic stabilization, the Levitron top induces levitation through a series of interactive steps. The levitated to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spin-stabilized Magnetic Levitation
Spin-stabilized magnetic levitation is a phenomenon of magnetic levitation whereby a spinning magnet or array of magnets (typically as a top) is levitated via magnetic forces above another magnet or array of magnets, and stabilised by gyroscopic effect due to a spin that is neither too fast, nor too slow to allow for a necessary precession. The phenomenon was originally discovered through invention by Vermont inventor Roy M. Harrigan in the 1970s. On May 3, 1983 Harrigan received a United States patent for his original levitation device based upon this phenomenon he discovered. Independent of Harrigan, a Pennsylvanian inventor named Joseph Chieffo made the same discovery in 1984 employing a flat base magnet, a geometry that proved a significant change over his predecessor's design which relied upon a dish shaped mounting of magnets for the base. Chieffo's design, publicized in a 1991 edition of the periodical "MAGNETS IN YOUR FUTURE", further differed from Harrigan's in its incor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spin-stabilized Magnetic Levitation
Spin-stabilized magnetic levitation is a phenomenon of magnetic levitation whereby a spinning magnet or array of magnets (typically as a top) is levitated via magnetic forces above another magnet or array of magnets, and stabilised by gyroscopic effect due to a spin that is neither too fast, nor too slow to allow for a necessary precession. The phenomenon was originally discovered through invention by Vermont inventor Roy M. Harrigan in the 1970s. On May 3, 1983 Harrigan received a United States patent for his original levitation device based upon this phenomenon he discovered. Independent of Harrigan, a Pennsylvanian inventor named Joseph Chieffo made the same discovery in 1984 employing a flat base magnet, a geometry that proved a significant change over his predecessor's design which relied upon a dish shaped mounting of magnets for the base. Chieffo's design, publicized in a 1991 edition of the periodical "MAGNETS IN YOUR FUTURE", further differed from Harrigan's in its incor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Levitation
Magnetic levitation (maglev) or magnetic suspension is a method by which an object is suspended with no support other than magnetic fields. Magnetic force is used to counteract the effects of the gravitational force and any other forces. The two primary issues involved in magnetic levitation are ''lifting forces'': providing an upward force sufficient to counteract gravity, and ''stability'': ensuring that the system does not spontaneously slide or flip into a configuration where the lift is neutralized. Magnetic levitation is used for maglev trains, contactless melting, magnetic bearings and for product display purposes. Lift Magnetic materials and systems are able to attract or repel each other with a force dependent on the magnetic field and the area of the magnets. For example, the simplest example of lift would be a simple dipole magnet positioned in the magnetic fields of another dipole magnet, oriented with like poles facing each other, so that the force between mag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrodynamic Bearing
A magnetic bearing is a type of bearing that supports a load using magnetic levitation. Magnetic bearings support moving parts without physical contact. For instance, they are able to levitate a rotating shaft and permit relative motion with very low friction and no mechanical wear. Magnetic bearings support the highest speeds of any kind of bearing and have no maximum relative speed. Active bearings have several advantages: they do not suffer from wear, have low friction, and can often accommodate irregularities in the mass distribution automatically, allowing rotors to spin around their center of mass with very low vibration. Passive magnetic bearings use permanent magnets and, therefore, do not require any input power but are difficult to design due to the limitations described by Earnshaw's theorem. Techniques using diamagnetic materials are relatively undeveloped and strongly depend on material characteristics. As a result, most magnetic bearings are active magnetic beari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Bearing
A magnetic bearing is a type of bearing that supports a load using magnetic levitation. Magnetic bearings support moving parts without physical contact. For instance, they are able to levitate a rotating shaft and permit relative motion with very low friction and no mechanical wear. Magnetic bearings support the highest speeds of any kind of bearing and have no maximum relative speed. Active bearings have several advantages: they do not suffer from wear, have low friction, and can often accommodate irregularities in the mass distribution automatically, allowing rotors to spin around their center of mass with very low vibration. Passive magnetic bearings use permanent magnets and, therefore, do not require any input power but are difficult to design due to the limitations described by Earnshaw's theorem. Techniques using diamagnetic materials are relatively undeveloped and strongly depend on material characteristics. As a result, most magnetic bearings are active magnetic bear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permanent Magnet
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets. A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include the elements iron, nickel and cobalt and their alloys, some alloys of rare-earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Educational Toys
Educational toys (sometimes also called "instructive toys") are objects of play, generally designed for children, which are expected to stimulate learning. They are often intended to meet an educational purpose such as helping a child develop a particular skill or teaching a child about a particular subject. They often simplify, miniaturize, or even model activities and objects used by adults. Although children are constantly interacting with and learning about the world, many of the objects they interact with and learn from are not toys. Toys are generally considered to be specifically built for children's use. A child might play with and learn from a rock or a stick, but it would not be considered an educational toy because 1) it is a natural object, not a designed one, and 2) it has no expected educational purpose. The difference lies in perception or reality of the toy's intention and value. An educational toy is expected to educate. It is expected to instruct, promot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Devices
Magnetism is the class of physical attributes that are mediated by a magnetic field, which refers to the capacity to induce attractive and repulsive phenomena in other entities. Electric currents and the magnetic moments of elementary particles give rise to a magnetic field, which acts on other currents and magnetic moments. Magnetism is one aspect of the combined phenomena of electromagnetism. The most familiar effects occur in ferromagnetic materials, which are strongly attracted by magnetic fields and can be magnetization, magnetized to become permanent magnets, producing magnetic fields themselves. Demagnetizing a magnet is also possible. Only a few substances are ferromagnetic; the most common ones are iron, cobalt, and nickel and their alloys. The rare-earth metals neodymium and samarium are less common examples. The prefix ' refers to iron because permanent magnetism was first observed in lodestone, a form of natural iron ore called magnetite, Fe3O4. All substances exhibit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Brands
Fortune Brands was a holding company founded in 1969 as American Brands, renamed in 1997 and split apart in 2011. The corporate headquarters was in Deerfield, Illinois, in the United States. The company had diversified product lines. It announced on December 8, 2010, that it would focus on its liquor business, and spin off or sell other parts of the company including home furnishings, hardware and golf products.Fortune Brands Announces Intent to Separate Company's Three Businesses , ''The Wall Street Journal'', December 8, 2010. The company sold its and |
Electrodynamic Wheel
An electrodynamic wheel is a type of wheel proposed for use in electrodynamic levitation of the maglev train transport system. Unlike a conventional wheel, an electrodynamic wheel has a rim studded with magnets of alternating poles. As the wheel spins, which is done at a rate so that there is slip between the rim and the guideway's surface, magnetic fields are induced in the conductive guideway which repels the wheel. Depending on the spin, electrodynamic wheels can provide propulsion, braking, control and lift. Using 2D model The mechanical rotation of a radially positioned permanent-magnet Halbach array above a conducting, nonmagnetic track induces eddy currents in the track that can inductively create suspension and propulsion forces simultaneously. The parameters that affect the performance of this electrodynamic wheel are studied using a 2-D steady-state finite-element method. Examples The Hendo hoverboard uses electrodynamic wheels to levitate itself over a conductive su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pro Se
''Pro se'' legal representation ( or ) comes from Latin ''pro se'', meaning "for oneself" or "on behalf of themselves" which, in modern law, means to argue on one's own behalf in a legal proceeding, as a defendant or plaintiff in civil cases, or a defendant in criminal cases, rather than have representation from counsel or an attorney. This status is sometimes known as ''in propria persona'' (abbreviated to "pro per"). In England and Wales the comparable status is that of "litigant in person". Prevalence According to the National Center for State Courts in the United States, as of 2006 ''pro se'' litigants had become more common in both state courts and federal courts. Estimates of the ''pro se'' rate of family law overall averaged 67% in California, 73% in Florida's large counties, and 70% in some Wisconsin counties. In San Diego, for example, the number of divorce filings involving at least one ''pro se'' litigant rose from 46% in 1992 to 77% in 2000, in Florida from 66% ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
