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Resistive Wire
Resistance wire is wire intended for making electrical resistors (which are used to control the amount of current in a circuit). It is better if the alloy used has a high resistivity, since a shorter wire can then be used. In many situations, the stability of the resistor is of primary importance, and thus the alloy's temperature coefficient of resistivity and corrosion resistance play a large part in material selection. When resistance wire is used for heating elements (in electric heaters, toasters, and the like), high resistivity and oxidation resistance is important. Sometimes resistance wire is insulated by ceramic powder and sheathed in a tube of another alloy. Such heating elements are used in electric ovens and water heaters, and in specialized forms for cooktops. __TOC__ Types Nichrome, a non-magnetic 80/20 alloy of nickel and chromium, is the most common resistance wire for heating purposes because it has a high resistivity and resistance to oxidation at high temper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wire
file:Sample cross-section of high tension power (pylon) line.jpg, Overhead power cabling. The conductor consists of seven strands of steel (centre, high tensile strength), surrounded by four outer layers of aluminium (high conductivity). Sample diameter 40 mm A wire is a flexible, round bar of metal. Wires are commonly formed by drawing (manufacturing), drawing the metal through a hole in a Die (manufacturing), die or draw plate. Wire gauges come in various standard sizes, as expressed in terms of a American wire gauge, gauge number or IEC 60228, cross-sectional area. Wires are used to bear mechanical Structural load, loads, often in the form of wire rope. In electricity and Signal (electronics), telecommunications signals, ''wire'' can refer to electrical cable, which can contain a solid core of a single wire or separate strands in stranded or braided forms. Usually cylinder (geometry), cylindrical in geometry, wire can also be made in square, hexagonal, flattened rectangular, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nichrome
Nichrome (also known as NiCr, nickel-chromium or chromium-nickel) is a family of alloys of nickel and chromium (and occasionally iron) commonly used as resistance wire, heating elements in devices like toasters, electrical kettles and space heaters, in some dental restorations (fillings) and in a few other applications. Patented in 1906 by Albert Marsh (US patent 811,859), nichrome is the oldest documented form of resistance heating alloy. The A Grade nichrome alloy is 80% nickel and 20% chromium by mass, but there are many other combinations of metals for various applications. Properties C Grade Nichrome is consistently silvery in color, is corrosion-resistant, has a high melting point of approximately , and has an electrical resistivity of around 1.12 μΩ·m, which is around 66 times higher resistivity than copper of 16.78 nΩ·m. Some nichrome formulations have a resistivity as low as 1.0 μΩ·m or as high as 1.5 μΩ·m. Almost any conductive w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wire
file:Sample cross-section of high tension power (pylon) line.jpg, Overhead power cabling. The conductor consists of seven strands of steel (centre, high tensile strength), surrounded by four outer layers of aluminium (high conductivity). Sample diameter 40 mm A wire is a flexible, round bar of metal. Wires are commonly formed by drawing (manufacturing), drawing the metal through a hole in a Die (manufacturing), die or draw plate. Wire gauges come in various standard sizes, as expressed in terms of a American wire gauge, gauge number or IEC 60228, cross-sectional area. Wires are used to bear mechanical Structural load, loads, often in the form of wire rope. In electricity and Signal (electronics), telecommunications signals, ''wire'' can refer to electrical cable, which can contain a solid core of a single wire or separate strands in stranded or braided forms. Usually cylinder (geometry), cylindrical in geometry, wire can also be made in square, hexagonal, flattened rectangular, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balco Alloy
Balco is a nickel-iron alloy with a thermal conductivity similar to nickel but twice the resistivity. It is used for making low cost resistance temperature sensors. It consists of 70% nickel and 30% iron. Balco is Carpenter Technology Corporation's brand name for this alloy consisting of 70% nickel and 30% iron. It is also sold by Harrison as "Hytemco". Its principal use is for resistance thermometers (resistance temperature detectors). These change their electrical resistances as a predictable function of temperature, making it useful as a thermometer with electrical output. Balco has a temperature coefficient of resistance of 0.00518 Ω/Ω/°C nearly as high as that of pure nickel (0.00672) but with much better linearity. It is also mechanically strong and fairly corrosion resistant. Pure platinum is preferred for the most precise resistance temperature detector elements in spite of its price and lower temperature coefficient (0.00385). This is because of its long-term st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manganin
Manganin is a trademarked name for an alloy of typically 84.2% copper, 12.1% manganese, and 3.7% nickel. It was first developed by Edward Weston in 1892, improving upon his Constantan (1887). Manganin foil and wire is used in the manufacture of resistors, particularly ammeter shunts, because of its virtually zero temperature coefficient of resistance value and long term stability. Several Manganin resistors served as the legal standard for the ohm in the United States from 1901 to 1990. Manganin wire is also used as an electrical conductor in cryogenic systems, minimizing heat transfer between points which need electrical connections. Manganin is also used in gauges for studies of high-pressure shock waves (such as those generated from the detonation of explosives) because it has low strain sensitivity but high hydrostatic pressure Hydrostatics is the branch of fluid mechanics that studies fluids at hydrostatic equilibrium and "the pressure in a fluid or exerted by a fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constantan
Constantan, also known in various contexts as Eureka, Advance, and Ferry, refers to a copper-nickel alloy commonly used for its stable electrical resistance across a wide range of temperatures. It usually consists of 55% copper and 45% nickel. Its main feature is the low thermal variation of its resistivity, which is constant over a wide range of temperatures. Other alloys with similarly low temperature coefficients are known, such as manganin (Cu 6%/ Mn 2%/ Ni %). History In 1887, Edward Weston discovered that metals can have a negative temperature coefficient of resistance, inventing what he called his "Alloy No. 2." It was produced in Germany where it was renamed "Konstantan". Constantan alloy Of all alloys used in modern strain gauges, constantan is the oldest, and still the most widely used. This situation reflects the fact that constantan has the best overall combination of properties needed for many strain gauge applications. This alloy has, for example, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crimp Connection
Crimping is a method of joining two or more pieces of metal or other ductile material by deforming one or both of them to hold the other. The bend or deformity is called the crimp. Crimping tools are used to create crimps. Crimping is used extensively in metalworking, including to contain bullets in cartridge cases, for electrical connections, and for securing lids on metal food cans. Because it can be a cold-working technique, crimping can also be used to form a strong bond between the workpiece and a non-metallic component. It is also used to connect two pieces of food dough. Tools A crimping tool or crimp tool is used to create crimps. Crimping tools range in size from small handheld devices, to benchtop machines used for industrial purposes, to large fully-automatic wire processing machines for high-volume production. For electrical crimps, a wide variety of crimping tools exist, and they are generally designed for a specific type and size of terminal. Handheld tools ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kanthal (alloy)
Kanthal is the trademark for a family of iron-chromium-aluminium (FeCrAl) alloys used in a wide range of resistance and high-temperature applications. Kanthal FeCrAl alloys consist of mainly iron, chromium (20–30 wt%) and aluminium (4–7.5 wt%). The first Kanthal FeCrAl alloy was developed by Hans von Kantzow in Hallstahammar, Sweden. The alloys are known for their ability to withstand high temperatures and having intermediate electric resistance. As such, it is frequently used in heating elements. The trademark Kanthal is owned by '' Alleima AB''. Characteristics For heating, resistance wire must be stable in air when hot. Kanthal FeCrAl alloy forms a protective layer of aluminium oxide (alumina). Aluminium oxide has high thermal conductivity but is an electrical insulator, so special techniques may be required to make good electrical connections. Ordinary Kanthal FeCrAl alloy has a melting point of . Special grades can be used as high as . Depending on specific compositi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nickel
Nickel is a chemical element; it has symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive, but large pieces are slow to react with air under standard conditions because a passivation layer of nickel oxide forms on the surface that prevents further corrosion. Even so, pure native nickel is found in Earth's crust only in tiny amounts, usually in ultramafic rocks, and in the interiors of larger nickel–iron meteorites that were not exposed to oxygen when outside Earth's atmosphere. Meteoric nickel is found in combination with iron, a reflection of the origin of those elements as major end products of supernova nucleosynthesis. An iron–nickel mixture is thought to compose Earth's outer and inner cores. Use of nickel (as natural meteoric nickel–iron alloy) has been traced as far back as 3500 BCE. Nickel was first isolated and classifie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetism
Magnetism is the class of physical attributes that occur through a magnetic field, which allows objects to attract or repel each other. Because both electric currents and magnetic moments of elementary particles give rise to a magnetic field, magnetism is one of two aspects of electromagnetism. The most familiar effects occur in ferromagnetic materials, which are strongly attracted by magnetic fields and can be 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, nickel, and their alloys. All substances exhibit some type of magnetism. Magnetic materials are classified according to their bulk susceptibility. Ferromagnetism is responsible for most of the effects of magnetism encountered in everyday life, but there are actually several types of magnetism. Paramagnetic substances, such as aluminium and oxygen, are weakly attracted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cooktop
A cooktop (American English), stovetop (Canadian and American English) or hob (British English), is a device commonly used for cooking that is commonly found in kitchens and used to apply heat to the base of cookware, pans or pots. Cooktops are often found integrated with an oven into a kitchen stove but may also be standalone devices. Cooktops are commonly powered by gas or electricity, although oil or other fuels are sometimes used. Gas Gas cooktops consist of one or more gas burners with arrangements to control the rate of flow. They often have integral lighters or (in older models) pilot lights, and may have safety interlocks designed to reduce the risk of hazardous gas leaks. Gas cooking has been associated with negative health effects, such as reduced pulmonary function and a higher rate of respiratory symptoms in children. Electric Coil An electric coil cooktop uses electric elements that directly heat pots placed on them. They are inexpensive to buy and maintain, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resistor
A resistor is a passive two-terminal electronic component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses. High-power resistors that can dissipate many watts of electrical power as heat may be used as part of motor controls, in power distribution systems, or as test loads for generators. Fixed resistors have resistances that only change slightly with temperature, time or operating voltage. Variable resistors can be used to adjust circuit elements (such as a volume control or a lamp dimmer), or as sensing devices for heat, light, humidity, force, or chemical activity. Resistors are common elements of electrical networks and electronic circuits and are ubiquitous in electronic equipment. Practical resistors as discrete components can be composed of various compounds and forms. Resisto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
