EP0026871B1 - Core for electromagnetic induction device - Google Patents
Core for electromagnetic induction device Download PDFInfo
- Publication number
- EP0026871B1 EP0026871B1 EP19800105694 EP80105694A EP0026871B1 EP 0026871 B1 EP0026871 B1 EP 0026871B1 EP 19800105694 EP19800105694 EP 19800105694 EP 80105694 A EP80105694 A EP 80105694A EP 0026871 B1 EP0026871 B1 EP 0026871B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- elements
- core
- strip
- magnetic core
- recited
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F27/00—Details of transformers or inductances, in general
- H01F27/24—Magnetic cores
- H01F27/25—Magnetic cores made from strips or ribbons
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
- H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
- H01F1/147—Alloys characterised by their composition
- H01F1/153—Amorphous metallic alloys, e.g. glassy metals
- H01F1/15383—Applying coatings thereon
Definitions
- This invention relates to magnetic core structures of the art used defined in the prior art portion of claim 1, which core structures are in electrical induction apparatus such as transformers, motors, generators and the like.
- Magnetic devices such as transformers, motors, generators and the like oftentimes include wound core members composed of magnetically soft material.
- the material, in the form of continuous strip is typically wound on a suitable mandrel and annealed to relieve winding stresses. The mandrel is then removed from the core, which is cut and treated for receiving winding thereon.
- U.S. Patent No. 2,909,742 issued October 20, 1959 discloses a machine wound magnetic core
- British Patent No. 1,453,154 published 20 October 1976 discloses a magnetic core for a harmonic generating reactor.
- These magnetic cores include elements spirally wound from strips of magnetic steel and correspond to the art defined in the prior art portion of claim 1.
- U.S. Patent No. 4,038,073 issued July 26, 1977 discloses near-zero magnetostrictive glassy metal alloys with high saturation induction
- U.S. Patent No. 4,056,411 discloses certain amorphous alloys useful for making magnetic devices.
- toroidal core members One of the major problems with toroidal core members is the core loss produced by eddy currents present in and between wound layers of the strip. This loss, which varies as the square of strip width, is so large that it has previously been necessary to form the core from a number of laminated plates wound or stamped from the strip, individually coated with insulating material and wound or stacked one upon another on the flat side thereof. As a result, magnetic cores for electromagnetic induction devices have low operating efficiency and high construction and material costs.
- the magnetic core for an electromagnetic induction device that is economical to make and highly efficient in operation.
- the magnetic core comprises a plurality of magnetic core elements, each of which is formed by winding a plurality of layers of uninsulated strip of magnetically permeable material.
- the magnetic core elements are juxtaposed together to form a core stack, the height of which is large relative to the strip width of each element.
- the core elements are electrically isolated from each other by insulating material interposed between the elements at the region of juxtaposition.
- the magnetic core 12 comprises a plurality of magnetic core elements 14.
- Each of the core elements 14 is formed by winding a plurality of layers 16 of uninsulated strip 18 of magnetically permeable material.
- the elements 14 are juxtaposed together to form a core stack 20, the height, h, of which is large relative to the strip width, w, of each element.
- Core elements 14 are electrically isolated from each other by insulating material 22 interposed between the core elements 14 at the region of juxtaposition 24.
- the strip 18 used to wind the magnetic core elements 14 is composed of magnetically soft material.
- Such material desirably has the following combination of properties: (a) low hysteresis loss; (b) low eddy current loss; (c) low coercive force; (d) high magnetic permeability; (e) high saturation value; and (f) minimum change in permeability with temperature.
- Conventionally employed magnetically soft material in strip form such as high-purity iron, silicon steels, iron/nickel alloys, iron/cobalt alloys and the like, are all suitable for use in the practice of the present invention.
- the strip 18 is of amorphous (glassy) magnetic alloys which have recently become available.
- Such alloys are at least about 50% amorphous, as determined by x-ray diffraction.
- Such alloys include those having the formula MN-90 To-is X 10-25 1 wherein M is at least one of the elements iron, cobalt and nickel, wherein T is at least one of the transition metal elements, and X is at least one of the metalloid elements of phosphorus, boron and carbon. Up to 80 percent of the carbon, phosphorus and/or boron in X may be replaced by aluminum, antimony, beryllium, germanium, indium, silicon and tin. Used as cores of magnetic devices, such amorphous metal alloys evidence generally superior properties as compared to the conventional polycrystalline metal alloys commonly utilized. Preferably, strips of such amorphous alloys are at least about 80% amorphous, more preferably yet, at least about 95% amorphous.
- the amorphous magnetic alloys of which strip 18 is preferably composed are formed by cooling a melt at a rate of about 10 5 to 10 6 °C/sec.
- a variety of well-known techniques are available for fabricating rapid-quenched continuous strip.
- the strip 18 When used in magnetic cores for electromagnetic induction devices, the strip 18 typically has the form of wire or ribbon.
- the strip 18 is conveniently prepared by casting molten material directly onto a chill surface or into a quenching medium of some sort. Such processing techniques considerably reduce the cost of fabrication, since no intermediate wire- drawing or ribbon-forming procedures are required.
- the amorphous metal alloys of which strip 18 is preferably composed evidence high tensile strength, typically about 200,000 to 600,000 psi (1.38-4.14 x 10 6 kPa), depending on the particular composition. This is to be compared with polycrystalline alloys, which are used in the annealed condition and which usually range from about 40,000 to 80,000 psi (2.76-5.52 x 10 6 kPa).
- a high tensile strength is an important consideration in applications where high centrifugal forces are present, such as experienced by cores in motors and generators, since higher strength alloys allow higher rotational speeds.
- the amorphous metal alloys used to form strip 18 evidence a high electrical resistivity, ranging from about 160 to 180 microhm-cm at 25°C, depending on the particular composition. Typical prior art materials have resistivities of about 45 to 160 microhm/cm.
- the high resistivity possessed by the amorphous metal alloys defined above is useful in AC applications for minimizing eddy current losses, which, in turn, are a factor in reducing core loss.
- a further advantage of using amorphous metal alloys to form strip 18 is that lower coercive forces are obtained than with prior art compositions of substantially the same metallic content, thereby permitting more iron, which is relatively inexpensive, to be utilized in the strip 18, as compared with a greater proportion of nickel, which is more expensive.
- each of the magnetic core elements 14 is formed by winding successive turns of strip 18 on a mandrel (not shown). During winding of successive turns, strip 18 is kept under tension to effect tight formation of the core element 14.
- the number of turns required for a given core element 14 can range from a few turns to several thousand turns, depending upon the power capacity of the electromagnetic device desired.
- the strip 18 is cut across the width, w, thereof, the outer turn being held in wound relation to the preceding turn.
- the cut end of the last turn of strip 18 is spot welded, clamped or otherwise secured to the wound core element 14.
- the core element 14 has a width defined by the width of strip 18 and a build defined by the number of turns of strip 18 times the strip thickness, t.
- Amorphous metal strip is relatively thin as compared to rolled crystalline strip.
- the composite core construction of magnetic core 12 eliminates the necessity for individually coating each wound layer of strip 18 used to form core element 14. As a result, the core element 14 can be wound into a smaller, lighter element at lower construction, processing and material costs than magnetic cores having an insulated interlaminar construction.
- the width of strip 18 ranges from about .25 to 2.5 centimeters and the thickness of strip 18 ranges from about 1 to 2 mils (0,0025--0,005 cm).
- the build of each core element 14 can range from as low as 4 mils (0,01 cm) to as great as 25 centimeters or more depending upon the power requirements of the electromagnetic device.
- Magnetic core 12 is assembled by sandwiching a layer of insulating material 22 between plural core elements 14.
- the core elements 14 may be bonded together by the insulating material 22.
- core elements 14 and insulation layers 22 can be placed successively on a spool composed of thermoplastic or thermosetting material.
- the number of core elements 14 used to construct magnetic core 12, as well as the dimensions of the core elements 14 and overall height, h, of the magnetic core 12 will vary depending on the power capacity and operating frequency of the electromagnetic device.
- the maximum acceptable strip width is about 1 inch (2.54 cm)
- the number of core elements 14 used to construct magnetic core 12 is about 3 to 10
- the height, h, of magnetic core 12 is about 2 to 10 inches (5.08-25.4 cm)
- the inside diameter of each core element 14 is about 1 to 6 inches (2.54-1.52 cm) and the outside diameter of each core element 14 is about 2 to 20 inches (5.08-50.8 cm).
- the maximum acceptable strip width is about 1/4 inch (6.3 x 10- 1 cm)
- the number of core elements 14 used to construct magnetic core 12 is about 3 to 10
- the height h, of magnetic core 12 is about 2 to 10 inches (5.08-25.4 cm)
- the inside diameter of each core element 14 is about 1 to 3 inches (2.54-7.62 cm)
- the outside diameter of each core element 14 is about 2 to 10 inches (5.08-25.4 cm).
- the insulating layers 22 disposed between core elements 14 can be composed of any suitable insulating material such as thermosetting or thermoplastic material, glass cloth, fiberglass, polycarbonates, mica, CAPSTAN, LEXAN, fish paper and the like, having the required flexibility, dielectric strength, toughness and stability at the design operating temperature of the magnetic core 12, normally in the vicinity of 130°C.
- insulating layers 22 are in the form of a flexible film having a thickness of about 1/2 mil (0,001 cm) and inside and outside diameters substantially equivalent to those of core elements 14. Electrical isolation of core elements 14 can alternatively be accomplished by disposing insulating material over part of the build portions between adjoining core elements 14.
- the insulating layer 22 disposed between adjoining core elements 14 can have the form of a spider or other suitable configuration adapted to physically separate and electrically isolate the adjacent core elements 14.
- electrical isolation of core elements 14 is effected by an insulating layer 22 comprised in part of air.
- the insulating layer 22 can be painted, sprayed or otherwise applied to one or both of the adjoining surfaces of core elements 14.
- Construction of a transformer 11 incorporating magnetic core 12 can be readily effected by toroidal winding of primary and secondary turns 30, 32 of copper or aluminum wire or ribbon about the magnetic core 12, or by hand threading the copper or aluminum wire turns about the magnetic core 12 in a conventional manner.
- the elimination of the interlaminar insulation afforded by the sectionalized construction of magnetic core 12 substantially reduces the length of the copper turn required, and decreases the copper loss of the electromagnetic device 10.
- the magnetic core 12 is sectioned into "n" number of core elements 14 insulated from each other, in accordance with the invention, there will now be a current i flowing in each core element 14 due to an induced voltage e and an interlayer resistance r. Since the core area of the core element 14 is now n times smaller, the induced voltage e is:
- the interlayer core loss, p, of each element will be:
- n2 times less than when the core is wound as a single element In the 15 KVA transformer consisting of seven elements, the interlayer core loss is 49 times lower than it would be if it had been wound as a single section with 7 inch (17.78 cm) wide uncoated strip.
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Soft Magnetic Materials (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
Description
- This invention relates to magnetic core structures of the art used defined in the prior art portion of claim 1, which core structures are in electrical induction apparatus such as transformers, motors, generators and the like.
- Magnetic devices, such as transformers, motors, generators and the like oftentimes include wound core members composed of magnetically soft material. The material, in the form of continuous strip is typically wound on a suitable mandrel and annealed to relieve winding stresses. The mandrel is then removed from the core, which is cut and treated for receiving winding thereon.
- U.S. Patent No. 2,909,742 issued October 20, 1959 discloses a machine wound magnetic core, and British Patent No. 1,453,154 published 20 October 1976 discloses a magnetic core for a harmonic generating reactor. These magnetic cores include elements spirally wound from strips of magnetic steel and correspond to the art defined in the prior art portion of claim 1. U.S. Patent No. 4,038,073 issued July 26, 1977 discloses near-zero magnetostrictive glassy metal alloys with high saturation induction, and U.S. Patent No. 4,056,411 discloses certain amorphous alloys useful for making magnetic devices.
- One of the major problems with toroidal core members is the core loss produced by eddy currents present in and between wound layers of the strip. This loss, which varies as the square of strip width, is so large that it has previously been necessary to form the core from a number of laminated plates wound or stamped from the strip, individually coated with insulating material and wound or stacked one upon another on the flat side thereof. As a result, magnetic cores for electromagnetic induction devices have low operating efficiency and high construction and material costs.
- Briefly stated the present invention, defined in claim 1 provides a magnetic core for an electromagnetic induction device that is economical to make and highly efficient in operation. The magnetic core comprises a plurality of magnetic core elements, each of which is formed by winding a plurality of layers of uninsulated strip of magnetically permeable material. The magnetic core elements are juxtaposed together to form a core stack, the height of which is large relative to the strip width of each element. The core elements are electrically isolated from each other by insulating material interposed between the elements at the region of juxtaposition.
- The invention will be more fully understood and further advantages will become apparent when reference is made to the following detailed description of the preferred embodiment of the invention and the accompanying drawings, in which:
- Figure 1 is a perspective view of a transformer incorporating the composite core of this invention;
- Figure 2 is a section take through line 2-2 of Fig. 1; and
- Figure 3 is an exploded perspective view illustrating the composite core construction of the transformer shown in Fig. 1.
- Referring to Figures 1 and 2 of the drawings, there is shown generally at 10 an electromagnetic induction device having the
magnetic core 12 of this invention. Themagnetic core 12 comprises a plurality ofmagnetic core elements 14. Each of thecore elements 14 is formed by winding a plurality oflayers 16 ofuninsulated strip 18 of magnetically permeable material. Theelements 14 are juxtaposed together to form acore stack 20, the height, h, of which is large relative to the strip width, w, of each element.Core elements 14 are electrically isolated from each other byinsulating material 22 interposed between thecore elements 14 at the region ofjuxtaposition 24. - The
strip 18 used to wind themagnetic core elements 14 is composed of magnetically soft material. Such material desirably has the following combination of properties: (a) low hysteresis loss; (b) low eddy current loss; (c) low coercive force; (d) high magnetic permeability; (e) high saturation value; and (f) minimum change in permeability with temperature. Conventionally employed magnetically soft material in strip form, such as high-purity iron, silicon steels, iron/nickel alloys, iron/cobalt alloys and the like, are all suitable for use in the practice of the present invention. According to the invention however, thestrip 18 is of amorphous (glassy) magnetic alloys which have recently become available. Such alloys are at least about 50% amorphous, as determined by x-ray diffraction. Such alloys include those having the formula MN-90 To-is X10-251 wherein M is at least one of the elements iron, cobalt and nickel, wherein T is at least one of the transition metal elements, and X is at least one of the metalloid elements of phosphorus, boron and carbon. Up to 80 percent of the carbon, phosphorus and/or boron in X may be replaced by aluminum, antimony, beryllium, germanium, indium, silicon and tin. Used as cores of magnetic devices, such amorphous metal alloys evidence generally superior properties as compared to the conventional polycrystalline metal alloys commonly utilized. Preferably, strips of such amorphous alloys are at least about 80% amorphous, more preferably yet, at least about 95% amorphous. - The amorphous magnetic alloys of which
strip 18 is preferably composed are formed by cooling a melt at a rate of about 105 to 106°C/sec. A variety of well-known techniques are available for fabricating rapid-quenched continuous strip. When used in magnetic cores for electromagnetic induction devices, thestrip 18 typically has the form of wire or ribbon. Thestrip 18 is conveniently prepared by casting molten material directly onto a chill surface or into a quenching medium of some sort. Such processing techniques considerably reduce the cost of fabrication, since no intermediate wire- drawing or ribbon-forming procedures are required. - The amorphous metal alloys of which
strip 18 is preferably composed evidence high tensile strength, typically about 200,000 to 600,000 psi (1.38-4.14 x 106 kPa), depending on the particular composition. This is to be compared with polycrystalline alloys, which are used in the annealed condition and which usually range from about 40,000 to 80,000 psi (2.76-5.52 x 106 kPa). A high tensile strength is an important consideration in applications where high centrifugal forces are present, such as experienced by cores in motors and generators, since higher strength alloys allow higher rotational speeds. - In addition, the amorphous metal alloys used to form
strip 18 evidence a high electrical resistivity, ranging from about 160 to 180 microhm-cm at 25°C, depending on the particular composition. Typical prior art materials have resistivities of about 45 to 160 microhm/cm. The high resistivity possessed by the amorphous metal alloys defined above is useful in AC applications for minimizing eddy current losses, which, in turn, are a factor in reducing core loss. - A further advantage of using amorphous metal alloys to form
strip 18 is that lower coercive forces are obtained than with prior art compositions of substantially the same metallic content, thereby permitting more iron, which is relatively inexpensive, to be utilized in thestrip 18, as compared with a greater proportion of nickel, which is more expensive. - Referring to Figs. 2 and 3 of the drawings, each of the
magnetic core elements 14 is formed by winding successive turns ofstrip 18 on a mandrel (not shown). During winding of successive turns,strip 18 is kept under tension to effect tight formation of thecore element 14. The number of turns required for a givencore element 14 can range from a few turns to several thousand turns, depending upon the power capacity of the electromagnetic device desired. When the required number of turns are wound for a givencore element 14, thestrip 18 is cut across the width, w, thereof, the outer turn being held in wound relation to the preceding turn. Typically, the cut end of the last turn ofstrip 18 is spot welded, clamped or otherwise secured to thewound core element 14. - When sufficient turns have been wound to form a given
magnetic core element 14 as above described, the mandrel is removed therefrom to produce thecore element 14 shown in Fig. 3. Thecore element 14 has a width defined by the width ofstrip 18 and a build defined by the number of turns ofstrip 18 times the strip thickness, t. Amorphous metal strip is relatively thin as compared to rolled crystalline strip. Moreover, the composite core construction ofmagnetic core 12 eliminates the necessity for individually coating each wound layer ofstrip 18 used to formcore element 14. As a result, thecore element 14 can be wound into a smaller, lighter element at lower construction, processing and material costs than magnetic cores having an insulated interlaminar construction. Generally, the width ofstrip 18 ranges from about .25 to 2.5 centimeters and the thickness ofstrip 18 ranges from about 1 to 2 mils (0,0025--0,005 cm). The build of eachcore element 14 can range from as low as 4 mils (0,01 cm) to as great as 25 centimeters or more depending upon the power requirements of the electromagnetic device. -
Magnetic core 12 is assembled by sandwiching a layer ofinsulating material 22 betweenplural core elements 14. Thecore elements 14 may be bonded together by theinsulating material 22. Alternatively,core elements 14 andinsulation layers 22 can be placed successively on a spool composed of thermoplastic or thermosetting material. The number ofcore elements 14 used to constructmagnetic core 12, as well as the dimensions of thecore elements 14 and overall height, h, of themagnetic core 12 will vary depending on the power capacity and operating frequency of the electromagnetic device. For electromagnetic devices having an operating frequency of 60 Hz and a power capacity ranging from 100 to 20,000 watts, the maximum acceptable strip width is about 1 inch (2.54 cm) the number ofcore elements 14 used to constructmagnetic core 12 is about 3 to 10, the height, h, ofmagnetic core 12 is about 2 to 10 inches (5.08-25.4 cm) the inside diameter of eachcore element 14 is about 1 to 6 inches (2.54-1.52 cm) and the outside diameter of eachcore element 14 is about 2 to 20 inches (5.08-50.8 cm). For electromagnetic devices having an operating frequency of about 10 KHz and a power capacity ranging from 100 to 20,000 watts, the maximum acceptable strip width is about 1/4 inch (6.3 x 10-1 cm), the number ofcore elements 14 used to constructmagnetic core 12 is about 3 to 10, the height h, ofmagnetic core 12 is about 2 to 10 inches (5.08-25.4 cm), the inside diameter of eachcore element 14 is about 1 to 3 inches (2.54-7.62 cm) and the outside diameter of eachcore element 14 is about 2 to 10 inches (5.08-25.4 cm). - The insulating layers 22 disposed between
core elements 14 can be composed of any suitable insulating material such as thermosetting or thermoplastic material, glass cloth, fiberglass, polycarbonates, mica, CAPSTAN, LEXAN, fish paper and the like, having the required flexibility, dielectric strength, toughness and stability at the design operating temperature of themagnetic core 12, normally in the vicinity of 130°C. As shown in Fig. 3, insulatinglayers 22 are in the form of a flexible film having a thickness of about 1/2 mil (0,001 cm) and inside and outside diameters substantially equivalent to those ofcore elements 14. Electrical isolation ofcore elements 14 can alternatively be accomplished by disposing insulating material over part of the build portions between adjoiningcore elements 14. Thus, the insulatinglayer 22 disposed between adjoiningcore elements 14 can have the form of a spider or other suitable configuration adapted to physically separate and electrically isolate theadjacent core elements 14. In such a case, electrical isolation ofcore elements 14 is effected by an insulatinglayer 22 comprised in part of air. Still further, the insulatinglayer 22 can be painted, sprayed or otherwise applied to one or both of the adjoining surfaces ofcore elements 14. - Construction of a
transformer 11 incorporatingmagnetic core 12 can be readily effected by toroidal winding of primary andsecondary turns magnetic core 12, or by hand threading the copper or aluminum wire turns about themagnetic core 12 in a conventional manner. The elimination of the interlaminar insulation afforded by the sectionalized construction ofmagnetic core 12 substantially reduces the length of the copper turn required, and decreases the copper loss of theelectromagnetic device 10. - The reduction in core loss resulting from the composite core construction of
magnetic core 12 has been demonstrated by a 15 KVA transformer wound with sevencore elements 14 of 1 inch (2.54 cm) wideuncoated strip 18. - If the transformer core had been wound with
uncoated strip 18 in the form of wide ribbon in a single section, a current, I, would have flowed between the ribbon layers. This current would be - If, on the other hand, the
magnetic core 12 is sectioned into "n" number ofcore elements 14 insulated from each other, in accordance with the invention, there will now be a current i flowing in eachcore element 14 due to an induced voltage e and an interlayer resistance r. Since the core area of thecore element 14 is now n times smaller, the induced voltage e is: -
-
-
-
- Or, in other words, n2 times less than when the core is wound as a single element. In the 15 KVA transformer consisting of seven elements, the interlayer core loss is 49 times lower than it would be if it had been wound as a single section with 7 inch (17.78 cm) wide uncoated strip.
- Having thus described the invention in rather full detail it will be understood that these details need not be strictly adhered to but that various changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims.
Claims (9)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US8220979A | 1979-10-05 | 1979-10-05 | |
US82209 | 1979-10-05 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0026871A1 EP0026871A1 (en) | 1981-04-15 |
EP0026871B1 true EP0026871B1 (en) | 1984-02-15 |
Family
ID=22169755
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19800105694 Expired EP0026871B1 (en) | 1979-10-05 | 1980-09-23 | Core for electromagnetic induction device |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0026871B1 (en) |
JP (1) | JPS5658213A (en) |
CA (1) | CA1158325A (en) |
DE (1) | DE3066611D1 (en) |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4524342A (en) * | 1981-12-28 | 1985-06-18 | Allied Corporation | Toroidal core electromagnetic device |
US4506248A (en) * | 1983-09-19 | 1985-03-19 | Electric Power Research Institute, Inc. | Stacked amorphous metal core |
CA1211169A (en) * | 1984-04-03 | 1986-09-09 | Nicolai Alexandrov | Distribution transformer with woundmagnetic circuit |
US5868123A (en) * | 1995-10-05 | 1999-02-09 | Alliedsignal Inc. | Magnetic core-coil assembly for spark ignition systems |
US20060017010A1 (en) * | 2004-07-22 | 2006-01-26 | Axcelis Technologies, Inc. | Magnet for scanning ion beams |
JP4841327B2 (en) * | 2006-06-21 | 2011-12-21 | モリト株式会社 | Shoulder strap fittings, women's clothing with shoulder straps and cups |
EP2696358B1 (en) * | 2012-08-10 | 2018-10-10 | STS Spezial-Transformatoren-Stockach GmbH & Co. KG | Medium frequency transformer |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE937185C (en) * | 1941-02-12 | 1955-12-29 | Siemens Ag | Switching arrangement for alternating current interruption devices |
US2909742A (en) * | 1953-09-01 | 1959-10-20 | Gen Electric | Machine wound magnetic core |
US3838365A (en) * | 1973-02-05 | 1974-09-24 | Allied Chem | Acoustic devices using amorphous metal alloys |
BE807944A (en) * | 1973-11-28 | 1974-05-28 | Elphiac Sa | SELF WITH QUICK SATURATION HARMONICS GENERATOR FOR FREQUENCY MULTIPLIER DEVICE |
SE7511398L (en) * | 1974-10-21 | 1976-04-22 | Western Electric Co | MAGNETIC DEVICE |
US4056411A (en) * | 1976-05-14 | 1977-11-01 | Ho Sou Chen | Method of making magnetic devices including amorphous alloys |
US4038073A (en) * | 1976-03-01 | 1977-07-26 | Allied Chemical Corporation | Near-zero magnetostrictive glassy metal alloys with high saturation induction |
US4116728B1 (en) * | 1976-09-02 | 1994-05-03 | Gen Electric | Treatment of amorphous magnetic alloys to produce a wide range of magnetic properties |
-
1980
- 1980-09-23 EP EP19800105694 patent/EP0026871B1/en not_active Expired
- 1980-09-23 DE DE8080105694T patent/DE3066611D1/en not_active Expired
- 1980-09-29 CA CA000361216A patent/CA1158325A/en not_active Expired
- 1980-10-06 JP JP13973580A patent/JPS5658213A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
CA1158325A (en) | 1983-12-06 |
DE3066611D1 (en) | 1984-03-22 |
EP0026871A1 (en) | 1981-04-15 |
JPS6366045B2 (en) | 1988-12-19 |
JPS5658213A (en) | 1981-05-21 |
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PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
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Effective date: 19810921 |
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