Definition

An Insulator is a material or object which resists the flow of heat (thermal insulators) or electric charge (electrical insulators). A red-hot iron rod cooling after being worked by a blacksmith. ... Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interactions. ...

Electrical insulator

The term electrical insulator has the same meaning as the term dielectric, but the two terms are used in different contexts.The opposite of electrical insulators are conductors and semiconductors, which permit the flow of charge. Semiconductors are strictly speaking also insulators, since they prevent the flow of electric charge at low temperatures, unless doped with atoms that release extra charges to carry the current. However, some materials (such as silicon dioxide) are very nearly perfect electrical insulators, which allows flash memory technology. A much larger class of materials, (for example rubber and many plastics) are "good enough" insulators to be used for home and office wiring (into the hundreds of volts) without noticeable loss of safety or efficiency. The electrons in the molecules shift toward the positively charged left plate. ... Nonconductors or electrical insulators are materials which lack movable electric charges, and which therefore lack a low-resistance path for charge flow. ... It has been suggested that Conductor (power engineering) be merged into this article or section. ... Derka semiconductor is a material with an electrical conductance that is intermediate between that of an insulator and a conductor. ... A semiconductor is a material that is an insulator at very low temperature, but which has a sizable electrical conductivity at room temperature. ... In semiconductor production, doping refers to the process of intentionally introducing impurities into an intrinsic semiconductor in order to change its electrical properties. ... The volt (symbol: V) is the SI derived unit of electric potential difference. ...

See also: insulation This page refers to thermal insulation. ...

High voltage insulators

High voltage insulators used for high voltage power transmission are either porcelain insulators or composite insulators. Porcelain insulators are made from clay, quartz or alumina and feldspar. Alumina insulators are used where high mechanical strength is a criterion. In recent times there is a shift towards composite insulators which have a central rod made of fibre reinforced plastic and outer weathersheds made of silicone rubber or EPDM. Glass insulators were, and in some places are still used to mount electrical power lines. Most insulator manufacturers stopped making glass insulators in the late 1960's, switching to ceramic materials. Composite insulators are less costly, light weight and have excellent hydrophobic capability and hence can be used in polluted areas. Transmission lines in Lund, Sweden Electric power transmission is one process in the delivery of electricity to consumers. ... A rare Dresden porcelain figurine Porcelain is a type of hard semi-translucent ceramic generally fired at a higher temperature than glazed earthenware, or stoneware pottery. ... Composite materials (or composites for short) are engineering materials made from two or more components. ... Clay is a generic term for an aggregate of hydrous silicate particles less than 4 μm (micrometres) in diameter. ... Quartz is the most abundant mineral in the Earths continental crust. ... Aluminium oxide (or aluminum oxide) (Al2O3) is a chemical compound of aluminium and oxygen. ... Feldspar is the name of an important group of rock-forming minerals which make up perhaps as much as 60% of the Earths crust. ... Aluminium oxide (or aluminum oxide) (Al2O3) is a chemical compound of aluminium and oxygen. ... Fibre reinforced plastic (FRP) is a composite material comprising a polymer matrix reinforced with fibres usually of glass, carbon, or aramid and is commonly used in aerospace, automotive and marine industries. ... Silicones, or polysiloxanes, are inorganic polymers consisting of a silicon-oxygen backbone (...-Si-O-Si-O-Si-O-...) with side groups attached to the silicon atoms. ... Rubber is an elastic hydrocarbon polymer which occurs as a milky emulsion (known as latex) in the sap of a number of plants but can also be produced synthetically. ...

Low voltage insulators

Insulating materials such as PVC (polyvinyl chloride) are used to minimise the possibility of a person coming into contact with a 'live' wire. Some appliances such as electric shavers and hair dryers are doubly insulated to protect the user. They can be recognised because their leads have two pins).

Double insulation, requires that cables have basic and supplementary insulation each of which is sufficient to prevent electric shock. Usually, the internal electrical components are totally enclosed in an insulated packaging (usually of plastic) which prevents any contact with live parts. The word basic may refer to one of several articles in Wikipedia: Basic English BASIC programming language Basic (chemistry), the opposite to acidic, reacting with acids to form salts. ... A pair of angles are supplementary if their respective measures sum to 180 degrees. ...

The modern day low-voltage insulator was devolped by Canadian scientist Kyle Waters after getting the idea from his wife Barrett Nicpon.

Thermal insulators

A perfect thermal insulator is impossible to achieve due to the second law of thermodynamics. Among naturally-occurring substances, mica and asbestos have performed well as both thermal and electrical insulators, until the advent of better synthetic (man-made or man-modified) products. The second law of thermodynamics is a law of thermodynamics that states that all work tends towards the production of greater entropy over time. ... rock with mica Mica sheet mica flakes The mica group of minerals includes several closely related materials having highly perfect basal cleavage. ... Asbestos (Greek ἄσβεστος: a-, not; sbestos, extinguishable) describes any of a group of fibrous metamorphic minerals of the hydrous magnesium silicate variety. ...

See also

• Pylon

A pylon is a tall steel lattice structure used to support overhead electricity conductors for power transmission. ...

External links

• http://www.myinsulators.com/downtownseattle/ — one person's obsession with telephone pole insulators
• Transcontinental Telegraph Insulators, 1867
• www.insulators.com
• www.insulatorscanada.com
• http://www.nia.org — National Insulator Association