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A magnetic core is the core of an electromagnet or inductor. The properties of an electromagnet or inductor will be influenced by the core with the most important factors being: An electromagnet is a type of magnet in which the magnetic field is produced by a flow of electric current. ...
An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ...
An electromagnet is a type of magnet in which the magnetic field is produced by a flow of electric current. ...
An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ...
A magnetic circuit is a closed path containing a magnetic flux. ...
Permeability has several meanings: In electromagnetism, permeability is the degree of magnetisation of a material in response to a magnetic field. ...
Hysteresis is a property of systems (usually physical systems) that do not instantly follow the forces applied to them, but react slowly, or do not return completely to their original state: that is, systems whose states depend on their immediate history. ...
Commonly used magnetic core structures
Straight cylindrical rod Most commonly made of the ferrite or similar material, and used in radios especially for tuning an inductor. The rod sits in the middle of the coil and small adjustments of the rod position will fine tune the inductance. Often the rod is threaded to allow adjustment with a screwdriver. In radio circuits, a dob of wax or resin is used once the inductor has been tuned to prevent the core from moving. An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ...
Inductance (or electric inductance) is a measure of the amount of magnetic flux produced for a given electric current. ...
Screw thread, used to convert torque into the linear force in the flood gate. ...
Wax has traditionally referred to a substance that is secreted by bees (beeswax) and used by them in constructing their honeycombs. ...
Resin of a pine Insect trapped in resin. ...
The presence of the high permeability core increases the inductance but the field must still spread into the air at the ends of the rod. The path through the air ensures that the inductor remains linear. In this type of inductor radiation occurs at the end of the rod and electromagnetic interference may be a problem in some circumstances. Permeability has several meanings: In electromagnetism, permeability is the degree of magnetisation of a material in response to a magnetic field. ...
Inductance (or electric inductance) is a measure of the amount of magnetic flux produced for a given electric current. ...
AIR is a three-letter abbreviation with multiple meanings, as described below: The Annals of Improbable Research, a monthly magazine devoted to scientific humour All India Radio - Indias Government Radio service AIR, a popular electronica band from France. ...
An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ...
The word linear comes from the Latin word linearis, which means created by lines. ...
Radiation in physics is the process of emitting energy in the form of waves or particles. ...
Radio Frequency Interference (RFI) is electromagnetic radiation which is emitted by electrical circuits carrying rapidly changing signals, as a by-product of their normal operation, and which causes unwanted signals (interference or noise) to be induced in other circuits. ...
Single "I" core Like a cylindrical rod but square, rarely used on its own.
"C" or "U" core U and C-shaped cores are the simplest solution to form a closed magnetic circuit, when used alongside a I or another C or U' core. a U-shaped core, with sharp corners Image File history File links Download high-resolution version (1280x960, 64 KB) Summary Licensing Made using povray 3. ...
| the C-shaped core, with rounded corners Image File history File links Download high-resolution version (1280x960, 66 KB) Made using povray 3. ...
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"E" core E-shaped core are more symetric solutions to form a closed magnetic system. Most of the time, the electric circuit is wound around the center leg, whose section area is twice that of each individual outer leg. Classical E core Image File history File links Download high-resolution version (1280x960, 74 KB) Summary Licensing Made using povray 3. ...
| The EFD' core allows for construction of inductors or transformers with a lower profile Image File history File links Download high-resolution version (1280x960, 89 KB) Summary Licensing Made using povray v3. ...
| The ER core has a cylindrical central leg. Image File history File links Download high-resolution version (1280x960, 84 KB) Summary Licensing Made using povray 3. ...
| the EP core is halfways between a E and a pot core Image File history File links Download high-resolution version (1280x960, 115 KB) Summary Licensing #declare RAD = on; #include colors. ...
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"E" and "I" core Sheets of suitable iron stamped out in shapes like the (sans-serif) letters "E" and "I", are stacked with the "I" against the open end of the "E" to form 3-legged structure; coils can be wound around any leg, but usually the center leg is used. This type of core is much used for power transformers, autotransformers, and inductors. In typography, serifs are the small features at the end of strokes within letters. ...
Vintage German letter balance for home use Look up letter in Wiktionary, the free dictionary. ...
 Construction of an inductor using two ER cores, a plastic bobbin and two clips. The bobbin has pins to be soldered to a printed circuit board.
 Exploded view of the previous figure showing the structure Image File history File links Download high-resolution version (1280x960, 368 KB) Summary Licensing Made using povray 3. ...
Image File history File links Download high-resolution version (1280x960, 368 KB) Summary Licensing Made using povray 3. ...
Close-up photo of one side of a motherboard PCB, showing conductive traces, vias and solder points for through-hole components on the opposite side. ...
Image File history File links Download high-resolution version (1280x960, 225 KB) Summary Licensing made using povray 3. ...
Image File history File links Download high-resolution version (1280x960, 225 KB) Summary Licensing made using povray 3. ...
Pair of "E" cores Again used for iron cores. Similar to using an "E" and "I" together, a pair of "E" cores will accommodate a larger coil former and can produce a larger inductor or transformer. If an air gap is required, the centre leg of the "E" is shortened so that the air gap sits in the middle of the coil to minimise fringing and reduce electromagnetic interference. An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ...
Three-phase pole-mounted step-down transformer. ...
Radio Frequency Interference (RFI) is electromagnetic radiation which is emitted by electrical circuits carrying rapidly changing signals, as a by-product of their normal operation, and which causes unwanted signals (interference or noise) to be induced in other circuits. ...
Image File history File links Download high-resolution version (1280x960, 77 KB) Summary Licensing Made using povray 3. ...
Image File history File links Download high-resolution version (1280x960, 77 KB) Summary Licensing Made using povray 3. ...
Pot core Usually ferrite or similar. This is used for inductors and transformers. The shape of a pot core is round with an internal hollow that almost completely encloses the coil. Usually a pot core is made in two halves which fit together around a coil former (bobbin). This design of core has a shielding effect, preventing radiation and reducing electromagnetic interference. An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ...
Three-phase pole-mounted step-down transformer. ...
A bobbin is a spindle or cylinder, with or without flanges, on which wire, yarn, thread or film is wound. ...
Statue showing a Gallic shield with a butterfly boss. ...
Radiation in physics is the process of emitting energy in the form of waves or particles. ...
Radio Frequency Interference (RFI) is electromagnetic radiation which is emitted by electrical circuits carrying rapidly changing signals, as a by-product of their normal operation, and which causes unwanted signals (interference or noise) to be induced in other circuits. ...
Image File history File links Download high-resolution version (1280x960, 109 KB) Summary Licensing Made using povray 3. ...
Image File history File links Download high-resolution version (1280x960, 109 KB) Summary Licensing Made using povray 3. ...
Toroidal core This design is based on a circular toroid, similar in shape to a doughnut. The coil is wound through the hole in the doughnut and around the outside, an ideal coil is distributed evenly all around the circumference of the doughnut. This geometry will turn the magnetic field around into a full loop and thus will naturally keep the majority of the field constrained within the core material. It makes a highly efficient and low radiation transformer, popular in hi-fi audio amplifiers where desirable features are: high power, small volume and minimal electromagnetic interference. It is, however, more difficult to wind an electrical circuit around it than with a splitable core (a core made of two elements, like two E). Automatic winding of a toroidal core requires a specific machinery. A toroid is a doughnut-shaped object whose surface is a torus. ...
Doughnuts being glazed at a Krispy Kreme store in Sydney. ...
To meet Wikipedias quality standards, this article may require cleanup. ...
In physics and engineering, including mechanical and electrical engineering, energy efficiency is a dimensionless number, with a value between 0 and 1 or with times 100 given in percent. ...
Radiation in physics is the process of emitting energy in the form of waves or particles. ...
Three-phase pole-mounted step-down transformer. ...
In physics, power (symbol: P) is the rate at which work is performed. ...
Volume is a quantification of how much space a certain region occupies. ...
Radio Frequency Interference (RFI) is electromagnetic radiation which is emitted by electrical circuits carrying rapidly changing signals, as a by-product of their normal operation, and which causes unwanted signals (interference or noise) to be induced in other circuits. ...
Image File history File links Download high-resolution version (1280x960, 87 KB) Summary Licensing Made using povray 3. ...
Image File history File links Download high-resolution version (1280x960, 87 KB) Summary Licensing Made using povray 3. ...
Planar core A planar core consists of two flat pieces of magnetic material, one above and one below the coil. It is typically used with a flat coil that is part of a printed circuit board. This design is excellent for mass production and allows a high power, small volume transformer to be constructed for low cost. It is not as ideal as either a pot core or toroidal core but costs less to produce. Close-up photo of one side of a motherboard PCB, showing conductive traces, vias and solder points for through-hole components on the opposite side. ...
Mass production is the production of large amounts of standardised products on production lines. ...
In physics, power (symbol: P) is the rate at which work is performed. ...
Volume is a quantification of how much space a certain region occupies. ...
Three-phase pole-mounted step-down transformer. ...
 Exploded view that shows the spiral track made directly on the printed circuit board Image File history File links Download high-resolution version (1280x960, 207 KB) Summary Licensing Made using povray 3. ...
Image File history File links Download high-resolution version (1280x960, 207 KB) Summary Licensing Made using povray 3. ...
Image File history File links Download high-resolution version (1280x960, 209 KB) Summary Licensing Made using povray 3. ...
Image File history File links Download high-resolution version (1280x960, 209 KB) Summary Licensing Made using povray 3. ...
Core loss In a transformer or inductor, some of the power that would ideally be transferred through the device is lost in the core, resulting in heat. There are various reasons for such losses, the primary ones being: Three-phase pole-mounted step-down transformer. ...
An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ...
In physics, heat, symbolized by Q, is defined as energy in transit. ...
The larger the area of the hysteresis loop, the more loss per cycle. Hysteresis loss gets worse at lower frequencies. Hysteresis is a property of systems (usually physical systems) that do not instantly follow the forces applied to them, but react slowly, or do not return completely to their original state: that is, systems whose states depend on their immediate history. ...
Hysteresis is a property of systems (usually physical systems) that do not instantly follow the forces applied to them, but react slowly, or do not return completely to their original state: that is, systems whose states depend on their immediate history. ...
Sine waves of various frequencies; the lower waves have higher frequencies than those above. ...
The induction of eddy currents within the core causes a resistive loss. The higher the resistance of the core material the lower the loss. Lamination of the core material can reduce eddy current loss. This article or section does not cite its references or sources. ...
Electromagnetic induction is the production of an electrical potential difference (or voltage) across a conductor situated in a changing magnetic flux. ...
This article or section does not cite its references or sources. ...
Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ...
A laminate is a material constructed by uniting two or more layers of material together. ...
As the magnetic field changes, some magnetic domains grow while others shrink, thus the walls of the domains can be said to move. This movement absorbs energy. Ferromagnetism is a phenomenon by which a material can exhibit a spontaneous magnetization, and is one of the strongest forms of magnetism. ...
Ferromagnetism is a phenomenon by which a material can exhibit a spontaneous magnetization, and is one of the strongest forms of magnetism. ...
Common magnetic core materials
Laminated silicon steel -
Iron is desirable to make magnetic cores, as it can withstand high levels of magnetic field (up to 2.16 teslas at ambient temp [1]). However, as it is a relatively good conductor, it cannot be used in bulk form: Intense eddy currents would appear due to the magnetic field, resulting in huge losses (this is used in induction heating). Silicon steel is a soft magnetic material, a steel containing silicon, usually with virtually no other alloying elements. ...
General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ...
To meet Wikipedias quality standards, this article may require cleanup. ...
The tesla (symbol T) is the SI derived unit of magnetic flux density (or magnetic induction). ...
This article or section does not cite its references or sources. ...
A semiconductor induction heater with a small inductor Induction heating is the process of heating a metal object by electromagnetic induction, where eddy currents are generated within the metal and resistance leads to Joule heating of the metal. ...
Two techniques are commonly used together to increase the resistivity of iron: lamination and alloying of the iron with silicon
Lamination Laminated magnetic cores are made of thin, insulated iron sheets. Using this technique, the magnetic core is equivalent to many individual magnetic circuits, each one receiving only a small fraction of the magnetic flux (because their section is a fraction of the whole core section). Furthermore, these circuits have a resistance that is higher than that of a non-laminated core, also because of their reduced section. From this, it can be seen that the thinner the laminations, the lower the eddy currents. A laminate is a material constructed by uniting two or more layers of material together. ...
Electrical resistance is a measure of the degree to which an electrical component opposes the passage of current. ...
Silicon aloying A small addition of silicon to Iron (around 3%) results in a dramatic increase of the resistivity, up to four times higher. Further increase in Silicon concentration impairs the steel's mechanical properties, causing difficulties for rolling. And then it is said that if enough silicon is used it can cause the whole world to realise that Phil Crowley likes to take it up the bum General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance dark gray, bluish tinge...
Among the two types of silicon steel, grain-oriented (GO) and grain non-oriented (GNO), GO is most desirable for magnetic cores. It is anisotropic, offering better magnetic properties than GNO in one direction. As the magnetic field in inductor and transformer cores is static (compared to that in electric motors), it is possible to use GO steel in the preferred orientation. Silicon steel is a soft magnetic material, a steel containing silicon, usually with virtually no other alloying elements. ...
This article is being considered for deletion in accordance with Wikipedias deletion policy. ...
carbonyl iron -
Powdered cores made of carbonyl iron, a highly pure iron, have high stability of parameters across a wide range of temperatures and magnetic flux levels, with excellent Q factors between 50 kHz and 200 MHz. Carbonyl iron poweder are basically constituted of micrometer-size balls of iron wrapped in an isolating layer. This is equivalent to a microscopic laminated magnetic circuit (see silicon steel, above), hence reducing the eddy currents. Carbonyl iron is a highly pure (97. ...
Carbonyl iron is a highly pure (97. ...
Magnetic flux, is a measure of quantity of magnetism, taking account of the strength and the extent of a magnetic field. ...
The Q factor or quality factor is a measure of the rate at which a vibrating system dissipates its energy into heat. ...
A popular application of carbonyl iron-based magnetic cores is in broadband inductors. An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ...
Iron powder Powdered cores made of hydrogen reduced iron have higher permeability but lower Q. They are used mostly for electromagnetic interference filters and low-frequency chokes, mainly in switched-mode power supplies. Permeability has several meanings: In electromagnetism, permeability is the degree of magnetisation of a material in response to a magnetic field. ...
Radio Frequency Interference (RFI) is electromagnetic radiation which is emitted by electrical circuits carrying rapidly changing signals, as a by-product of their normal operation, and which causes unwanted signals (interference or noise) to be induced in other circuits. ...
Television signal splitter consisting of a hi-pass and a low-pass filter. ...
A switched-mode power supply, switch mode power supply, or SMPS, is an electronic power supply unit (PSU) that incorporates a switching regulator — an internal control circuit that switches the load current rapidly on and off in order to stabilize the output voltage. ...
Ferrite -
Ferrite ceramics are used for high-frequency applications. The ferrite materials can be engineered with a wide range of parameters. A stack of ferrite magnets Ferrites are ferromagnetic ceramic materials, compounds of iron, boron and barium or strontium or molybdenum. ...
A stack of ferrite magnets Ferrites are ferromagnetic ceramic materials, compounds of iron, boron and barium or strontium or molybdenum. ...
See also An inductor is a passive electrical device employed in electrical circuits for its property of inductance. ...
Three-phase pole-mounted step-down transformer. ...
A stack of ferrite magnets Ferrites are ferromagnetic ceramic materials, compounds of iron, boron and barium or strontium or molybdenum. ...
References - ^ Daniel Sadarnac, Les composants magnétiques de l'électronique de puissance, cours de Supélec, mars 2001 [in french]
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