526:
eddy currents. Finer particles allow operation at higher frequencies, as the eddy currents are mostly restricted to within the individual grains. Coating of the particles with an insulating layer, or their separation with a thin layer of a binder, lowers the eddy current losses. Presence of larger particles can degrade high-frequency performance. Permeability is influenced by the spacing between the grains, which form distributed air gap; the less gap, the higher permeability and the less-soft saturation. Due to large difference of densities, even a small amount of binder, weight-wise, can significantly increase the volume and therefore intergrain spacing.
366:
1152:
1325:
1048:
517:) that are non-crystalline or glassy. These are being used to create high-efficiency transformers. The materials can be highly responsive to magnetic fields for low hysteresis losses, and they can also have lower conductivity to reduce eddy current losses. Power utilities are currently making widespread use of these transformers for new installations. High mechanical strength and corrosion resistance are also common properties of metallic glasses which are positive for this application.
144:
793:
1140:
1337:
1028:
432:
lamination. Since the current in an eddy current loop is proportional to the area of the loop, this prevents most of the current from flowing, reducing eddy currents to a very small level. Since power dissipated is proportional to the square of the current, breaking a large core into narrow laminations reduces the power losses drastically. From this, it can be seen that the thinner the laminations, the lower the eddy current losses.
1268:
950:
1202:
982:
966:
686:, makes low audio noise. Loses inductance with increasing temperature, unlike the other materials; can be exploited by combining with other materials as a composite core, for temperature compensation. Saturation flux of about 1 tesla. Good temperature stability. Used in switching power supplies, pulse and flyback transformers, in-line noise filters, swing chokes, and in filters in
1128:
934:
907:
895:
421:
1214:
463:, offering better magnetic properties than GNO in one direction. As the magnetic field in inductor and transformer cores is always along the same direction, it is an advantage to use grain oriented steel in the preferred orientation. Rotating machines, where the direction of the magnetic field can change, gain no benefit from grain-oriented steel.
1782:. The loops flow perpendicular to the magnetic field axis. The energy of the currents is dissipated as heat in the resistance of the core material. The power loss is proportional to the area of the loops and inversely proportional to the resistivity of the core material. Eddy current losses can be reduced by making the core out of thin
664:
to compensate capacitance in long telephone lines. It is usable up to about 200 kHz to 1 MHz, depending on vendor. It is still used in above-ground telephone lines, due to its temperature stability. Underground lines, where temperature is more stable, tend to use ferrite cores due to their
673:
An alloy of about 50–50% of nickel and iron. High energy storage, saturation flux density of about 1.5 tesla. Residual flux density near zero. Used in applications with high DC current bias (line noise filters, or inductors in switching regulators) or where low residual flux density is needed (e.g.
924:
E-shaped core are more symmetric 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. In 3-phase transformer cores, the legs are of equal size, and all three legs are wound.
540:
Powdered iron is the cheapest material. It has higher core loss than the more advanced alloys, but this can be compensated for by making the core bigger; it is advantageous where cost is more important than mass and size. Saturation flux of about 1 to 1.5 tesla. Relatively high hysteresis and eddy
525:
Powder cores consist of metal grains mixed with a suitable organic or inorganic binder, and pressed to desired density. Higher density is achieved with higher pressure and lower amount of binder. Higher density cores have higher permeability, but lower resistance and therefore higher losses due to
283:
In some cases the losses are undesirable and with very strong fields saturation can be a problem, and an 'air core' is used. A former may still be used; a piece of material, such as plastic or a composite, that may not have any significant magnetic permeability but which simply holds the coils of
614:
The as-prepared particles, "E-type"and have onion-like skin, with concentric shells separated with a gap. They contain significant amount of carbon. They behave as much smaller than what their outer size would suggest. The "C-type" particles can be prepared by heating the E-type ones in hydrogen
431:
magnetic cores are made of stacks of thin iron sheets coated with an insulating layer, lying as much as possible parallel with the lines of flux. The layers of insulation serve as a barrier to eddy currents, so eddy currents can only flow in narrow loops within the thickness of each single
1347:
The ring core may also be composed of two separate C-shaped hemispheres secured together within a plastic shell, permitting it to be placed on finished cables with large connectors already installed, that would prevent threading the cable through the small inner diameter of a solid ring.
1798:
By definition, this category includes any losses in addition to eddy-current and hysteresis losses. This can also be described as broadening of the hysteresis loop with frequency. Physical mechanisms for anomalous loss include localized eddy-current effects near moving domain walls.
548:
The binder used is usually epoxy or other organic resin, susceptible to thermal aging. At higher temperatures, typically above 125 °C, the binder degrades and the core magnetic properties may change. With more heat-resistant binders the cores can be used up to 200 °C.
716:. The grain size of the powder reaches down to 10–100 nanometers. The material has very good performance at lower frequencies. It is used in chokes for inverters and in high power applications. It is available under names like e.g. Nanoperm, Vitroperm, Hitperm and Finemet.
1667:
1019:"E" and "I", are stacked with the "I" against the open end of the "E" to form a 3-legged structure. Coils can be wound around any leg, but usually the center leg is used. This type of core is frequently used for power transformers, autotransformers, and inductors.
400:) limits the eddy currents to circulate within each individual lamination, reducing the total current. In this diagram the field and currents are shown in one direction, but they actually reverse direction with the alternating current in the transformer winding.
657:, and 17% iron. Very low core loss, low hysteresis and therefore low signal distortion. Very good temperature stability. High cost. Maximum saturation flux of about 0.8 tesla. Used in high-Q filters, resonant circuits, loading coils, transformers, chokes, etc.
2123:
Losses in magnetic materials can be characterized by the
Steinmetz coefficients, which however do not take into account temperature variability. Material manufacturers provide data on core losses in tabular and graphical form for practical conditions of use.
738:
are used for high-frequency applications. The ferrite materials can be engineered with a wide range of parameters. As ceramics, they are essentially insulators, which prevents eddy currents, although losses such as hysteresis losses can still occur.
1899:
1344:
The ring is essentially identical in shape and performance to the toroid, except that inductors commonly pass only through the center of the core, without wrapping around the core multiple times.
541:
current loss, operation limited to lower frequencies (approx. below 100 kHz). Used in energy storage inductors, DC output chokes, differential mode chokes, triac regulator chokes, chokes for
1503:
field for the material, which has the form of a closed loop. The net energy that flows into the inductor expressed in relationship to the B-H characteristic of the core is shown by the equation
502:
in hydrogen atmosphere in a magnetic field; subsequent sharper bends disrupt its grain alignment, leading to localized loss of permeability; this can be regained by repeating the annealing step.
2313:"How to choose Iron Powder, Sendust, Koolmu, High Flux and MPP Cores as output inductor and chokes : CWS Coil Winding Specialist, manufacturer of transformers, inductors, coils and chokes"
1509:
751:. This includes coils wound on a plastic or ceramic form in addition to those made of stiff wire that are self-supporting and have air inside them. Air core coils generally have a much lower
1760:
260:
material in the center of the coil can increase the magnetic field by hundreds or thousands of times; this is called a magnetic core. The field of the wire penetrates the core material,
1177:. 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 (
1306:
cores), specialized machinery is required for automated winding of a toroidal core. Toroids have less audible noise, such as mains hum, because the magnetic forces do not exert
1491:. This process causes losses, because the domain walls get "snagged" on defects in the crystal structure and then "snap" past them, dissipating energy as heat. This is called
812:. The coil is wound around the rod, or a coil form with the rod inside. Moving the rod in or out of the coil changes the flux through the coil, and can be used to adjust the
2244:
2038:
674:
pulse and flyback transformers, the high saturation is suitable for unipolar drive), especially where space is constrained. The material is usable up to about 200 kHz.
1412:
498:
to reach their magnetic properties, and lose them when subjected to mechanical or thermal abuse. For example, the permeability of mu-metal increases about 40 times after
2106:
452:
is used in transformer cores. Further increase in silicon concentration impairs the steel's mechanical properties, causing difficulties for rolling due to brittleness.
328:
and so does not remain magnetised when the field is removed, which is often important in applications where the magnetic field is required to be repeatedly switched.
1935:
264:
it, so that the strong magnetic field of the core adds to the field created by the wire. The amount that the magnetic field is increased by the core depends on the
1957:
339:
circulating within it, closed loops of electric current in planes perpendicular to the field. The current flowing through the resistance of the metal heats it by
1245:). The coil is wound through the hole in the torus and around the outside. An ideal coil is distributed evenly all around the circumference of the torus. The
624:
2082:
2060:
2009:
1983:
1253:
of circular loops inside the core, and the lack of sharp bends will constrain virtually all of the field to the core material. This not only makes a highly
1092:
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
1077:
112:
by a factor of several hundred times what it would be without the core. However, magnetic cores have side effects which must be taken into account. In
1068:
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
552:
Iron powder cores are most commonly available as toroids. Sometimes as E, EI, and rods or blocks, used primarily in high-power and high-current parts.
309:(DC) electromagnets and in some electric motors; and it can create a concentrated field that is as much as 50,000 times more intense than an air core.
1299:. The main drawback that limits their use for general purpose applications is the inherent difficulty of winding wire through the center of a torus.
1821:
1672:
This equation shows that the amount of energy lost in the material in one cycle of the applied field is proportional to the area inside the
1332:
rod with connection wires glued to the ends. On the right, a molded ferrite rod with holes, with a single wire threaded through the holes.
2669:
779:
are still present. Air cores are also used when field strengths above around 2 Tesla are required as they are not subject to saturation.
2366:
532:
The surface of the particles is often oxidized and coated with a phosphate layer, to provide them with mutual electrical insulation.
2344:. Göteborg, Sweden: Department of Energy and Environment, Division of Electric Power Engineering, Chalmers University of Technology
1076:. 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 minimize
859:
Like a cylindrical rod but is square, rarely used on its own. This type of core is most likely to be found in car ignition coils.
1786:
which have an insulating coating, or alternatively, making the core of a magnetic material with high electrical resistance, like
597:, particularly at very high frequencies. Carbonyl iron has lower losses than hydrogen-reduced iron, but also lower permeability.
343:, causing significant power losses. Therefore, solid iron cores are not used in transformers or inductors, they are replaced by
101:
to be concentrated in the core material. The magnetic field is often created by a current-carrying coil of wire around the core.
2524:
1662:{\displaystyle W=\int {\left(nA_{c}{\frac {dB(t)}{t}}\right)\left({\frac {H(t)l_{m}}{n}}\right)dt}=(A_{c}l_{m})\int {HdB}}
2688:
2148:
1232:
886:
core to make a square closed core, the simplest closed core shape. Windings may be put on one or both legs of the core.
772:
2698:
2621:
696:
The material was invented in Japan in 1936. It is usable up to about 500 kHz to 1 MHz, depending on vendor.
2549:
2499:
2474:
2446:
2419:
2391:
2376:
1686:
529:
Lower permeability materials are better suited for higher frequencies, due to balancing of core and winding losses.
404:
In order to reduce the eddy current losses mentioned above, most low frequency power transformers and inductors use
1960:
1364:
value of a core configuration is frequently specified by manufacturers. The relationship between inductance and A
168:
593:. This is equivalent to a microscopic laminated magnetic circuit (see silicon steel, above), hence reducing the
693:
Absence of nickel results in easier processing of the material and its lower cost than both high-flux and MPP.
17:
1815:
densities. The equation has three loss components: hysteresis, residual, and eddy current, and it is given by
1310:
on the core. The core is only in compression or tension, and the circular shape is more stable mechanically.
2586:
1449:, some of the power that would ideally be transferred through the device is lost in the core, dissipated as
1288:
1261:
1254:
1190:
1081:
848:
628:
276:
can cause frequency-dependent energy losses, different core materials are used for coils used at different
2578:
167:
in it. The drawing shows a section through the core. The purpose of the core is to provide a closed high
2338:
1676:. Since the energy lost in each cycle is constant, hysteresis power losses increase proportionally with
585:
between 50 kHz and 200 MHz. Carbonyl iron powders are basically constituted of micrometer-size
2693:
2265:
Inoue, A.; Kong, F. L.; Han, Y.; Zhu, S. L.; Churyumov, A.; Shalaan, E.; Al-Marzouki, F. (2018-01-15).
635:
2266:
1779:
1182:
229:
2016:
2339:"Powder Material for Inductor Cores, Evaluation of MPP, Sendust and High flux core characteristics"
483:. They can be manufactured as stampings or as long ribbons for tape wound cores. Some alloys, e.g.
459:, grain-oriented (GO) and grain non-oriented (GNO), GO is most desirable for magnetic cores. It is
2659:
1790:. Most magnetic cores intended for power converter application use ferrite cores for this reason.
1374:
2118:
1787:
1771:
1488:
1329:
2168:
335:(AC) applications such as transformers and inductors, the changing magnetic field induces large
687:
600:
A popular application of carbonyl iron-based magnetic cores is in high-frequency and broadband
499:
298:
2436:
2409:
2089:
331:
Due to the electrical conductivity of the metal, when a solid one-piece metal core is used in
1276:
1093:
1038:
590:
448:
of the metal, up to four times higher. The higher resistivity reduces the eddy currents, so
317:
265:
46:
1910:
2673:
2312:
2208:
2138:
1465:, the loss in the windings. Iron losses are often described as being in three categories:
221:
109:
31:
1942:
682:
An alloy of 6% aluminium, 9% silicon, and 85% iron. Core losses higher than MPP. Very low
8:
1474:
332:
129:
113:
98:
2212:
324:
at ambient temperature.) Annealed iron is used because, unlike "hard" iron, it has low
128:
in applications such as transformers and inductors. "Soft" magnetic materials with low
2599:
2067:
2045:
1994:
1968:
801:
249:
188:
the magnetic field lines "bulge" out, so the field strength is less than in the core:
70:
2267:"Development and application of Fe-based soft magnetic bulk metallic glassy inductors"
2627:
2617:
2545:
2520:
2495:
2470:
2442:
2415:
2372:
2286:
2226:
1016:
839:
from one end of the rod to the other. The air path ensures that the inductor remains
776:
631:
54:
2664:
1157:
Exploded view that shows the spiral track made directly on the printed circuit board
176:– magnetic field in the core will be approximately constant across any cross section
2595:
2278:
2216:
768:
735:
683:
471:
A family of specialized alloys exists for magnetic core applications. Examples are
348:
252:. A coil without a magnetic core is called an "air core" coil. Adding a piece of
137:
94:
2579:"Magnetic Measurements at Low Flux Densities Using the Alternating Current Bridge"
2392:
http://www.jmag-international.com/catalog/101_ChokeCoil_CurrentCharacteristic.html
2282:
763:
that occur in magnetic cores. The absence of normal core losses permits a higher
708:
alloy of a standard iron-boron-silicon alloy, with addition of smaller amounts of
627:
have higher permeability but lower Q than carbonyl iron. They are used mostly for
1774:, the changing magnetic field induces circulating loops of current in it, called
1673:
1492:
1484:
1296:
1101:
1097:
756:
705:
510:
365:
121:
1151:
615:
atmosphere at 400 °C for prolonged time, resulting in carbon-free powders.
1307:
1250:
1037:
cores, a plastic bobbin and two clips. The bobbin has pins to be soldered to a
573:, a highly pure iron, have high stability of parameters across a wide range of
495:
313:
306:
245:
225:
105:
82:
66:
50:
959:
core allows for construction of inductors or transformers with a lower profile
2682:
2290:
2230:
1480:
1053:
594:
578:
570:
564:
456:
449:
409:
360:
340:
312:
Iron is desirable to make magnetic cores, as it can withstand high levels of
261:
257:
253:
233:
133:
90:
86:
58:
2631:
1324:
1047:
1775:
1319:
1292:
817:
730:
661:
542:
336:
321:
269:
207:
125:
1368:
number in the linear portion of the magnetisation curve is defined to be:
828:
is used once the inductor has been tuned to prevent the core from moving.
555:
Carbonyl iron is significantly more expensive than hydrogen-reduced iron.
1894:{\displaystyle {\frac {R_{\text{ac}}}{\mu L}}=aB_{\text{max}}f+cf+ef^{2}}
1462:
1434:
1257:
1174:
1108:
1073:
605:
574:
480:
460:
445:
405:
385:
241:
143:
117:
78:
62:
1336:
2197:"New Determinations of the Saturation Magnetization of Nickel and Iron"
2143:
1986:
1783:
1446:
1139:
1012:
832:
813:
752:
650:
428:
344:
325:
273:
159:
in a typical magnetic core transformer or inductor, with the iron core
2221:
2196:
1483:
of the core material changes by expansion and contraction of the tiny
1417:
where n is the number of turns, L is the inductance (e.g. in nH) and A
1275:
It is popular for applications where the desirable features are: high
796:
Ferrite rods are simple cylinders of ferrite that can be wound around.
97:. The high permeability, relative to the surrounding air, causes the
1808:
1677:
1284:
1186:
844:
820:
to allow adjustment with a screwdriver. In radio circuits, a blob of
792:
760:
488:
476:
277:
42:
2411:
Engineering Basics: Electrical, Electronics and
Computer Engineering
545:
correction, resonant inductors, and pulse and flyback transformers.
1442:
1438:
1246:
1242:
1170:
1069:
1027:
809:
764:
601:
582:
472:
237:
210:; magnetic field lines which don't follow complete magnetic circuit
74:
2407:
1302:
Unlike a split core (a core made of two elements, like a pair of
713:
514:
484:
441:
2245:"Metglas® Amorphous Metal Materials – Distribution Transformers"
1433:
magnetic field, as it is in devices that use AC current such as
2408:
Thyagarajan, T.; Sendur Chelvi, K.P.; Rangaswamy, T.R. (2007).
1280:
1238:
1178:
1111:
to be constructed for low cost. It is not as ideal as either a
1105:
840:
755:
than similarly sized ferromagnetic core coils, but are used in
709:
654:
586:
1267:
2460:
2458:
2336:
2133:
1454:
825:
805:
1421:
is expressed in inductance per turn squared (e.g. in nH/n).
641:
Hydrogen-reduced iron cores are often called "power cores".
2670:
How to use ferrites for EMI suppression via
Wayback Machine
1812:
1450:
1213:
949:
835:, but the magnetic field lines must still pass through the
302:
2643:
2564:
2455:
1201:
981:
965:
444:
to iron (around 3%) results in a dramatic increase of the
232:. Coils are widely used in electronic components such as
2414:(3rd ed.). New Age International. pp. 184–185.
2183:
Les composants magnétiques de l'électronique de puissance
1127:
933:
906:
894:
836:
831:
The presence of the high permeability core increases the
821:
771:, such as up to a few megahertz. However, losses such as
420:
1011:
Sheets of suitable iron stamped out in shapes like the (
104:
The use of a magnetic core can increase the strength of
2660:
Online calculator for ferrite coil winding calculations
1006:
1680:. The final equation for the hysteresis power loss is
1479:
When the magnetic field through the core changes, the
862:
690:(e.g. dimmers) where low acoustic noise is important.
2092:
2070:
2048:
2019:
1997:
1971:
1945:
1913:
1824:
1689:
1512:
1377:
347:
or powdered iron cores, or nonconductive cores like
2519:(Second ed.). Chichester: Wiley. p. 113.
747:A coil not containing a magnetic core is called an
660:The material was first introduced in 1940, used in
268:of the core material. Because side effects such as
2539:
2464:
2100:
2076:
2054:
2032:
2003:
1977:
1951:
1929:
1893:
1754:
1661:
1406:
2665:What are the bumps at the end of computer cables?
2542:Fundamentals of Power Electronics, Second Edition
2467:Fundamentals of Power Electronics, Second Edition
2195:Danan, H.; Herr, A.; Meyer, A.J.P. (1968-02-01).
611:Carbonyl iron cores are often called "RF cores".
2680:
2614:Soft ferrites : properties and applications
2441:. Vol. 2 (4th ed.). IET. p. 195.
1807:An equation known as Legg's equation models the
220:An electric current through a wire wound into a
27:Object used to guide and confine magnetic fields
2264:
1755:{\displaystyle P_{H}=(f)(A_{c}l_{m})\int {HdB}}
767:, so air core coils are used in high frequency
2194:
1063:
163:forming a closed loop, possibly with air gaps
116:(AC) devices they cause energy losses, called
2540:Erickson, Robert; Maksimović, Dragan (2001).
2465:Erickson, Robert; Maksimović, Dragan (2001).
1937:is the effective core loss resistance (ohms),
1169:Usually ferrite or similar. This is used for
2514:
2360:
2358:
1056:of the previous figure showing the structure
854:
2544:. Kluwer Academic Publishers. p. 507.
2494:. Tata McGraw-Hill Education. p. 128.
2469:. Kluwer Academic Publishers. p. 506.
787:
782:
2368:Handbook of Modern Ferromagnetic Materials
2332:
2330:
2328:
2326:
1487:it is composed of, due to movement of the
354:
85:, and magnetic assemblies. It is made of
2648:, Marengo, IL: Arnold Engineering Company
2594:(1), Bell Telephone Laboratories: 39–63,
2434:
2371:. Springer Science & Business Media.
2355:
2220:
2112:
759:circuits to prevent energy losses called
2611:
2306:
2304:
2302:
2300:
1340:A ferrite ring on a computer data cable.
1335:
1323:
1266:
851:may be a problem in some circumstances.
791:
618:
419:
408:cores, made of stacks of thin sheets of
364:
142:
2385:
2364:
2323:
912:The C-shaped core, with rounded corners
228:through the center of the coil, due to
14:
2681:
2616:(2nd ed.). London: Butterworths.
2492:Basic Electrical Engineering, Volume 1
2489:
2337:Johan Kindmark, Fredrik Rosén (2013).
1765:
1495:. It can be seen in the graph of the
1033:Construction of an inductor using two
644:
380:within a solid iron transformer core.
155:created by a current-carrying winding
2297:
919:
2576:
2040:is the maximum flux density (gauss),
1468:
668:
634:and low-frequency chokes, mainly in
2644:Arnold Engineering Company (n.d.),
2149:Toroidal inductors and transformers
2011:is the hysteresis loss coefficient,
1793:
1233:Toroidal inductors and transformers
975:core has a cylindrical central leg.
900:A U-shaped core, with sharp corners
435:
24:
2600:10.1002/j.1538-7305.1936.tb00718.x
2517:High-frequency magnetic components
2310:
1802:
699:
677:
589:of iron coated in a thin layer of
520:
184:– "fringing fields". In the gaps
171:path for the magnetic field lines.
25:
2710:
2653:
2435:Whitfield, John Frederic (1995).
2365:Goldman, Alex (6 December 2012).
2062:is the residual loss coefficient,
847:occurs at the end of the rod and
505:
487:, are manufactured as powder and
466:
215:
2577:Legg, Victor E. (January 1936),
2515:Kazimierczuk, Marian K. (2014).
2311:others, The Zen Cart™ Team and.
1457:. Core loss is commonly termed
1429:When the core is subjected to a
1226:
1212:
1200:
1150:
1138:
1126:
1046:
1026:
980:
964:
948:
932:
905:
893:
608:, especially higher power ones.
558:
305:is used in magnetic assemblies,
2605:
2570:
2565:Arnold Engineering Company n.d.
2558:
2533:
2508:
2483:
2428:
2401:
2271:Journal of Alloys and Compounds
1313:
1291:. One such application is the
1096:. This design is excellent for
494:Many materials require careful
287:
2258:
2237:
2188:
2185:, cours de Supélec, mars 2001
2175:
2161:
2033:{\displaystyle B_{\text{max}}}
1735:
1712:
1709:
1703:
1642:
1619:
1586:
1580:
1556:
1550:
1328:On the left, a non-adjustable
1087:
804:or powdered iron, and used in
396:with insulation between them (
13:
1:
2587:Bell System Technical Journal
2283:10.1016/j.jallcom.2017.08.240
2154:
2108:is the eddy loss coefficient.
2084:is the frequency (hertz), and
1181:). This design of core has a
513:is a variety of alloys (e.g.
415:
140:, are usually used in cores.
57:and magnetic devices such as
30:For the computer memory, see
1770:If the core is electrically
1424:
1407:{\displaystyle L=n^{2}A_{L}}
1289:electromagnetic interference
1262:electromagnetic interference
1191:electromagnetic interference
1082:electromagnetic interference
874:-shaped cores are used with
849:electromagnetic interference
636:switched-mode power supplies
629:electromagnetic interference
384:Making the core out of thin
292:
7:
2438:Electrical Craft Principles
2127:
1351:
1249:of this geometry creates a
1164:
1119:but costs less to produce.
843:. In this type of inductor
719:
10:
2715:
2689:Electromagnetic components
2201:Journal of Applied Physics
2116:
1472:
1317:
1237:This design is based on a
1230:
991:core is halfway between a
728:
724:
562:
358:
49:used to confine and guide
29:
2699:Electromagnetic radiation
2381:– via Google Books.
2101:{\displaystyle {\ce {e}}}
1780:electromagnetic induction
808:especially for tuning an
1461:in contradistinction to
788:Straight cylindrical rod
783:Commonly used structures
132:and hysteresis, such as
2612:Snelling, E.C. (1988).
1260:, but also reduces the
1207:A pot core of 'RM' type
688:phase-fired controllers
623:Powdered cores made of
581:levels, with excellent
569:Powdered cores made of
535:
455:Among the two types of
355:Laminated silicon steel
89:metal such as iron, or
2113:Steinmetz coefficients
2102:
2078:
2056:
2034:
2005:
1979:
1953:
1931:
1930:{\displaystyle R_{ac}}
1895:
1756:
1663:
1408:
1341:
1333:
1272:
1264:radiated by the coil.
800:Most commonly made of
797:
742:
425:
424:Typical EI Lamination.
401:
388:parallel to the field
230:Ampere's circuital law
212:
2490:Dhogal, P.S. (1986).
2103:
2079:
2057:
2035:
2006:
1980:
1961:material permeability
1954:
1932:
1896:
1757:
1664:
1409:
1339:
1327:
1270:
1241:(the same shape as a
1094:printed circuit board
1039:printed circuit board
795:
649:An alloy of about 2%
625:hydrogen reduced iron
619:Hydrogen-reduced iron
591:electrical insulation
423:
368:
266:magnetic permeability
146:
47:magnetic permeability
2674:Murata Manufacturing
2139:Magnetic-core memory
2119:Steinmetz's equation
2090:
2068:
2046:
2017:
1995:
1969:
1952:{\displaystyle \mu }
1943:
1911:
1822:
1687:
1510:
1375:
440:A small addition of
110:electromagnetic coil
99:magnetic field lines
32:Magnetic-core memory
2213:1968JAP....39..669D
1766:Eddy-current losses
1475:Magnetic hysteresis
1185:effect, preventing
816:. Often the rod is
645:MPP (molypermalloy)
333:alternating current
114:alternating current
2098:
2074:
2052:
2030:
2001:
1975:
1949:
1927:
1891:
1752:
1659:
1404:
1342:
1334:
1273:
1219:A Regular Pot Core
1100:and allows a high
798:
426:
402:
213:
93:compounds such as
2694:Radio electronics
2526:978-1-118-71779-0
2222:10.1063/1.2163571
2181:Daniel Sadarnac,
2096:
2077:{\displaystyle f}
2055:{\displaystyle c}
2027:
2004:{\displaystyle a}
1978:{\displaystyle L}
1860:
1845:
1834:
1811:core loss at low
1809:magnetic material
1603:
1563:
1499:field versus the
1469:Hysteresis losses
1145:A planar inductor
1133:A planar 'E' core
1064:Pair of "E" cores
777:dielectric losses
769:resonant circuits
669:High-flux (Ni-Fe)
55:electromechanical
43:magnetic material
16:(Redirected from
2706:
2649:
2636:
2635:
2609:
2603:
2602:
2583:
2574:
2568:
2562:
2556:
2555:
2537:
2531:
2530:
2512:
2506:
2505:
2487:
2481:
2480:
2462:
2453:
2452:
2432:
2426:
2425:
2405:
2399:
2389:
2383:
2382:
2362:
2353:
2352:
2350:
2349:
2343:
2334:
2321:
2320:
2308:
2295:
2294:
2262:
2256:
2255:
2253:
2251:
2241:
2235:
2234:
2224:
2192:
2186:
2179:
2173:
2172:
2169:"Soft iron core"
2165:
2107:
2105:
2104:
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2097:
2094:
2083:
2081:
2080:
2075:
2061:
2059:
2058:
2053:
2039:
2037:
2036:
2031:
2029:
2028:
2025:
2010:
2008:
2007:
2002:
1984:
1982:
1981:
1976:
1958:
1956:
1955:
1950:
1936:
1934:
1933:
1928:
1926:
1925:
1900:
1898:
1897:
1892:
1890:
1889:
1862:
1861:
1858:
1846:
1844:
1836:
1835:
1832:
1826:
1794:Anomalous losses
1761:
1759:
1758:
1753:
1751:
1734:
1733:
1724:
1723:
1699:
1698:
1668:
1666:
1665:
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1658:
1641:
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1615:
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1604:
1599:
1598:
1597:
1575:
1569:
1565:
1564:
1559:
1542:
1540:
1539:
1485:magnetic domains
1413:
1411:
1410:
1405:
1403:
1402:
1393:
1392:
1216:
1204:
1154:
1142:
1130:
1050:
1030:
1007:"E" and "I" core
984:
968:
952:
936:
909:
897:
773:proximity effect
736:Ferrite ceramics
684:magnetostriction
436:Silicon alloying
393:
377:
284:wires in place.
195: <
152:
21:
2714:
2713:
2709:
2708:
2707:
2705:
2704:
2703:
2679:
2678:
2656:
2640:
2639:
2624:
2610:
2606:
2581:
2575:
2571:
2563:
2559:
2552:
2538:
2534:
2527:
2513:
2509:
2502:
2488:
2484:
2477:
2463:
2456:
2449:
2433:
2429:
2422:
2406:
2402:
2397:
2390:
2386:
2379:
2363:
2356:
2347:
2345:
2341:
2335:
2324:
2309:
2298:
2263:
2259:
2249:
2247:
2243:
2242:
2238:
2193:
2189:
2180:
2176:
2167:
2166:
2162:
2157:
2130:
2121:
2115:
2093:
2091:
2088:
2087:
2069:
2066:
2065:
2047:
2044:
2043:
2024:
2020:
2018:
2015:
2014:
1996:
1993:
1992:
1970:
1967:
1966:
1944:
1941:
1940:
1918:
1914:
1912:
1909:
1908:
1885:
1881:
1857:
1853:
1837:
1831:
1827:
1825:
1823:
1820:
1819:
1805:
1803:Legg's equation
1796:
1768:
1741:
1729:
1725:
1719:
1715:
1694:
1690:
1688:
1685:
1684:
1674:hysteresis loop
1648:
1636:
1632:
1626:
1622:
1593:
1589:
1576:
1574:
1570:
1543:
1541:
1535:
1531:
1527:
1523:
1522:
1511:
1508:
1507:
1493:hysteresis loss
1477:
1471:
1427:
1420:
1398:
1394:
1388:
1384:
1376:
1373:
1372:
1367:
1363:
1358:
1355:
1322:
1316:
1297:audio amplifier
1271:A toroidal core
1235:
1229:
1224:
1223:
1222:
1221:
1220:
1217:
1209:
1208:
1205:
1167:
1162:
1161:
1160:
1159:
1158:
1155:
1147:
1146:
1143:
1135:
1134:
1131:
1098:mass production
1090:
1066:
1061:
1060:
1059:
1058:
1057:
1051:
1043:
1042:
1031:
1009:
1004:
1003:
1002:
1001:
1000:
985:
977:
976:
969:
961:
960:
953:
945:
944:
937:
922:
917:
916:
915:
914:
913:
910:
902:
901:
898:
865:
863:"C" or "U" core
857:
855:Single "I" core
790:
785:
757:radio frequency
745:
733:
727:
722:
706:nanocrystalline
702:
700:Nanocrystalline
680:
678:Sendust, KoolMU
671:
647:
621:
567:
561:
538:
523:
521:Powdered metals
511:Amorphous metal
508:
469:
438:
418:
391:
375:
363:
357:
295:
290:
246:electric motors
218:
211:
204:
199:
193:
182:
177:
172:
150:
147:Magnetic field
83:recording heads
67:electric motors
53:in electrical,
51:magnetic fields
35:
28:
23:
22:
15:
12:
11:
5:
2712:
2702:
2701:
2696:
2691:
2677:
2676:
2667:
2662:
2655:
2654:External links
2652:
2651:
2650:
2638:
2637:
2623:978-0408027601
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2395:
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2354:
2322:
2317:www.coilws.com
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2187:
2174:
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1473:Main article:
1470:
1467:
1453:and sometimes
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1391:
1387:
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1380:
1365:
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1353:
1350:
1318:Main article:
1315:
1312:
1308:bending moment
1287:, and minimal
1277:specific power
1251:magnetic field
1231:Main article:
1228:
1225:
1218:
1211:
1210:
1206:
1199:
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563:Main article:
560:
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506:Vitreous metal
504:
496:heat treatment
468:
467:Special alloys
465:
437:
434:
417:
414:
372:Eddy currents
359:Main article:
356:
353:
314:magnetic field
307:direct current
294:
291:
289:
286:
234:electromagnets
226:magnetic field
217:
216:Core materials
214:
202:
191:
180:
106:magnetic field
59:electromagnets
41:is a piece of
26:
18:Laminated core
9:
6:
4:
3:
2:
2711:
2700:
2697:
2695:
2692:
2690:
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2663:
2661:
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2551:9780792372707
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2501:9780074515860
2497:
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2476:9780792372707
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2448:9780852968338
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2284:
2280:
2277:: 1303–1309.
2276:
2272:
2268:
2261:
2246:
2240:
2232:
2228:
2223:
2218:
2214:
2210:
2207:(2): 669–70.
2206:
2202:
2198:
2191:
2184:
2178:
2170:
2164:
2160:
2150:
2147:
2145:
2142:
2140:
2137:
2135:
2132:
2131:
2125:
2120:
2086:
2071:
2064:
2049:
2042:
2021:
2013:
1998:
1991:
1988:
1972:
1965:
1962:
1946:
1939:
1922:
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1905:
1886:
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1818:
1817:
1816:
1814:
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1800:
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1789:
1785:
1781:
1777:
1776:eddy currents
1773:
1748:
1745:
1742:
1738:
1730:
1726:
1720:
1716:
1706:
1700:
1695:
1691:
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1675:
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1637:
1633:
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1609:
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1600:
1594:
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1583:
1577:
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1524:
1519:
1516:
1513:
1506:
1505:
1504:
1502:
1498:
1494:
1490:
1486:
1482:
1481:magnetization
1476:
1466:
1464:
1460:
1456:
1452:
1448:
1444:
1440:
1436:
1432:
1422:
1399:
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1369:
1349:
1345:
1338:
1331:
1326:
1321:
1311:
1309:
1305:
1300:
1298:
1294:
1290:
1286:
1282:
1279:per mass and
1278:
1269:
1265:
1263:
1259:
1256:
1252:
1248:
1244:
1240:
1234:
1227:Toroidal core
1215:
1203:
1194:
1192:
1189:and reducing
1188:
1184:
1180:
1176:
1172:
1153:
1141:
1129:
1120:
1118:
1117:toroidal core
1114:
1110:
1107:
1103:
1099:
1095:
1085:
1083:
1079:
1075:
1071:
1055:
1054:Exploded view
1049:
1040:
1036:
1029:
1020:
1018:
1014:
998:
994:
990:
983:
974:
967:
958:
951:
942:
935:
926:
908:
896:
887:
885:
881:
877:
873:
869:
860:
852:
850:
846:
842:
838:
834:
829:
827:
823:
819:
815:
811:
807:
803:
794:
780:
778:
774:
770:
766:
762:
758:
754:
750:
740:
737:
732:
717:
715:
711:
707:
697:
694:
691:
689:
685:
675:
666:
663:
662:loading coils
658:
656:
652:
642:
639:
637:
633:
630:
626:
616:
612:
609:
607:
603:
598:
596:
595:eddy currents
592:
588:
584:
580:
579:magnetic flux
576:
572:
571:carbonyl iron
566:
565:carbonyl iron
559:Carbonyl iron
556:
553:
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457:silicon steel
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450:silicon steel
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410:silicon steel
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361:Silicon steel
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341:Joule heating
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337:eddy currents
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270:eddy currents
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258:ferrimagnetic
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84:
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40:
39:magnetic core
33:
19:
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2572:
2567:, p. 70
2560:
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2516:
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2491:
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2466:
2437:
2430:
2410:
2403:
2387:
2367:
2346:. Retrieved
2316:
2274:
2270:
2260:
2250:25 September
2248:. Retrieved
2239:
2204:
2200:
2190:
2182:
2177:
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2122:
1903:
1806:
1797:
1769:
1671:
1500:
1496:
1489:domain walls
1478:
1458:
1435:transformers
1430:
1428:
1416:
1359:
1346:
1343:
1320:Ferrite bead
1314:Ring or bead
1303:
1301:
1295:for a hi-fi
1293:power supply
1274:
1236:
1175:transformers
1168:
1116:
1112:
1091:
1067:
1034:
1010:
996:
992:
988:
972:
956:
940:
923:
883:
879:
875:
871:
867:
866:
858:
830:
799:
748:
746:
734:
731:Ferrite core
703:
695:
692:
681:
672:
665:lower cost.
659:
648:
640:
622:
613:
610:
606:transformers
599:
575:temperatures
568:
554:
551:
547:
543:power factor
539:
531:
528:
524:
509:
493:
470:
454:
439:
427:
403:
397:
389:
381:
373:
369:
330:
320:(up to 2.16
311:
296:
288:Solid metals
282:
242:transformers
219:
208:leakage flux
200:
196:
189:
185:
178:
173:
169:permeability
164:
160:
156:
148:
103:
79:loudspeakers
63:transformers
45:with a high
38:
36:
1784:laminations
1463:copper loss
1447:alternators
1258:transformer
1109:transformer
1088:Planar core
1080:and reduce
1074:transformer
878:or another
761:core losses
481:supermalloy
461:anisotropic
446:resistivity
386:laminations
278:frequencies
262:magnetizing
118:core losses
81:, magnetic
2683:Categories
2348:2017-06-05
2155:References
2144:Pole piece
1987:inductance
1772:conductive
1013:sans-serif
939:Classical
833:inductance
814:inductance
753:inductance
651:molybdenum
491:to shape.
416:Lamination
326:coercivity
318:saturating
274:hysteresis
250:generators
224:creates a
130:coercivity
122:hysteresis
71:generators
2646:MPP Cores
2291:0925-8388
2231:0021-8979
1989:(henrys),
1947:μ
1839:μ
1778:, due to
1739:∫
1678:frequency
1646:∫
1520:∫
1459:iron loss
1443:AC motors
1439:inductors
1425:Core loss
1285:mains hum
1255:efficient
1187:radiation
1183:shielding
1171:inductors
845:radiation
602:inductors
583:Q factors
500:annealing
477:permalloy
429:Laminated
406:laminated
345:laminated
293:Soft iron
238:inductors
120:, due to
75:inductors
2632:17875867
2128:See also
1431:changing
1247:symmetry
1243:doughnut
1165:Pot core
1113:pot core
1104:, small
1078:fringing
1070:inductor
920:"E" core
818:threaded
810:inductor
765:Q factor
749:air core
720:Ceramics
489:sintered
473:mu-metal
392:B, green
316:without
299:annealed
297:"Soft" (
95:ferrites
2209:Bibcode
1985:is the
1959:is the
1788:ferrite
1330:ferrite
1017:letters
802:ferrite
725:Ferrite
714:niobium
632:filters
587:spheres
515:Metglas
485:Sendust
442:silicon
382:(right)
349:ferrite
138:ferrite
2630:
2620:
2548:
2523:
2498:
2473:
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2418:
2375:
2289:
2229:
1904:where
1441:, and
1283:, low
1281:volume
1239:toroid
1179:bobbin
1106:volume
995:and a
841:linear
806:radios
710:copper
655:nickel
653:, 81%
479:, and
376:I, red
370:(left)
322:teslas
108:in an
2582:(PDF)
2398:Value
2342:(PDF)
2134:Balun
1455:noise
1360:The A
1356:value
1102:power
826:resin
157:(red)
151:green
136:, or
2628:OCLC
2618:ISBN
2546:ISBN
2521:ISBN
2496:ISBN
2471:ISBN
2443:ISBN
2416:ISBN
2373:ISBN
2287:ISSN
2252:2020
2227:ISSN
1813:flux
1451:heat
1445:and
1173:and
999:core
987:The
971:The
957:EFD'
955:The
943:core
870:and
775:and
712:and
604:and
577:and
536:Iron
303:iron
272:and
248:and
222:coil
124:and
2672:by
2596:doi
2394:, A
2279:doi
2275:731
2217:doi
2026:max
1859:max
1115:or
1072:or
997:pot
973:ETD
882:or
837:air
824:or
822:wax
743:Air
256:or
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1920:a
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941:E
884:U
880:C
876:I
872:C
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390:(
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203:L
201:B
197:B
192:F
190:B
186:G
181:F
179:B
174:B
165:G
161:C
153:)
149:(
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20:)
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