EP0122133B1 - Electrical winding - Google Patents

Electrical winding Download PDF

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Publication number
EP0122133B1
EP0122133B1 EP19840302366 EP84302366A EP0122133B1 EP 0122133 B1 EP0122133 B1 EP 0122133B1 EP 19840302366 EP19840302366 EP 19840302366 EP 84302366 A EP84302366 A EP 84302366A EP 0122133 B1 EP0122133 B1 EP 0122133B1
Authority
EP
European Patent Office
Prior art keywords
solenoid
winding
former
temperature
solenoid according
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
Application number
EP19840302366
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0122133A1 (en
Inventor
Peter Charles Bennett
Alastair Neish Grant
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co PLC
Original Assignee
General Electric Co PLC
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by General Electric Co PLC filed Critical General Electric Co PLC
Publication of EP0122133A1 publication Critical patent/EP0122133A1/en
Application granted granted Critical
Publication of EP0122133B1 publication Critical patent/EP0122133B1/en
Expired legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F5/00—Coils
    • H01F5/02—Coils wound on non-magnetic supports, e.g. formers
    • 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
    • H01F27/02—Casings
    • H01F27/027—Casings specially adapted for combination of signal type inductors or transformers with electronic circuits, e.g. mounting on printed circuit boards
    • 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
    • H01F27/08—Cooling; Ventilating
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/06—Electromagnets; Actuators including electromagnets
    • H01F7/20—Electromagnets; Actuators including electromagnets without armatures

Definitions

  • the present invention relates to the construction of electrical windings and in particular it relates to the construction of large accurately wound solenoids of the type used in nuclear magnetic resonance spectroscopy. More particularly, the invention relates to the design and construction of non-superconducting field coils for use in the whole-body imaging nuclear magnetic resonance spectrometers which have recently been developed for use in medical diagnosis and to such spectrometers incorporating the coils.
  • Such spectrometers are commonly known as medical N.M.R. spectrometers and will hereinafter be referred to as such. Medical N.M.R.
  • spectrometers are commonly provided with a set of three or four coaxial field coils disposed symmetrically along a horizontal axis in the Helmholtz or similar configurations capable of providing the required volume of uniform magnetic flux in an efficient manner.
  • the central coil or coils typically have a mean diameter of approximately 1.1 m and the two outer coils typically have a mean diameter of approximately 1.2 m.
  • the distance between the two outer coils is typically about 2 m.
  • the patient lies within the coils approximately along their common axis.
  • the flux density produced by a set of non-superconducting coils in this configuration is generally of the order of 0.2 Tesla.
  • field coils for use in medical N.M.R. spectrometers have generally been spiraly wound from insulated aluminium foil, each coil thus having one turn per layer. While such coils possess good dimensional accuracy when cold, they cannot easily be cooled and therefore tend to expand and distort when heated by the heavy currents used in operation of the spectrometer. Furthermore coils of this type tend to reach an equilibrium temperature distribution relatively slowly, and since they are necessarily wound fairly tightly, they tend to expand discontinuously and produce sudden local fluctuations in the magnetic field for some time after the spectrometer has been switched on.
  • An object of the present invention is to provide solenoid suitable for use as a field coil for an N.M.R. spectrometer in which these disadvantages are substantially eliminated. However the invention is also applicable to solenoids utilised for other purposes.
  • DE-B-1206500 discloses a high frequency communication transformer employing a plurality of elongated cross pieces supported at their ends only by a pair of end plates and around which there is wound a pair of conductors of a bifilar winding, but in this case only one conductor of the double winding lies on a cross piece, the other passing through a cut-out in the cross piece without touching it.
  • GB-A-326190 again relates to inductance coils of relatively small size, for example for use in a wave-meter and discloses coils having formers of Bakelite and Ebonite, in which elongate coil supporting members are supported solely by end cheeks.
  • a solenoid comprising a support structure incorporating a plurality of elongate elements parallel to and regularly spaced around an axis, and having locating means, such as slots, for accommodating the turns of one or more helical conductive windings, is characterised in that, for use as a central coil in a nuclear magnetic resonance spectrometer, the solenoid comprises a rigid, continuous cylindrical, former, the elongate elements are formed as separate members rigidly supported with respect to the outer surface of the former and are secured against axial movement relatively thereto, and the locating means of each element are regularly spaced along the element, and are dimensioned to prevent axial movement of the parts of a winding which they accommodate, so as to enable a substantially uniform magnetic field to be produced within the solenoid in use.
  • the former may comprise a rigid aluminium cylinder or alternatively a cylinder of synthetic plastics material maintained in a rigid condition by solidified insulating material bonded to it, the insulating material in such a case conveniently enclosing the winding.
  • Each locating means may simply comprise a slot dimensioned so as to grip the winding and thereby prevent axial movement of the part of the winding which it accommodates.
  • the elongate elements are adapted to rigidly support a further layer of'similar elongate elements incorporating similar sets of locating means on which a further layer of turns of the winding may be located.
  • said further layer of turns is wound in the opposite sense to the first layer of turns.
  • each elongate element in said further layer is located directly above and is attached to an elongate element of the supporting layer, for example by means of a free-flowing adhesive.
  • the elongate elements may be of aluminium, provided the winding is electrically insulated therefrom, although they are preferably in the form of glass-filled polyester resin sticks, and are axially located by flanges at the ends of the former.
  • the flanges may be integral with or attached to the former.
  • Each stick is conveniently formed from an even number of mouldings disposed about the central plane, with corresponding mouldings on opposite sides of the plane formed from the same or identical moulds and turned through 180° about a radial axis, so that they are mirror images of one another. This assists in the provision of a uniform magnetic field as it ensures an identical spacing and location of the winding turns on opposite sides of the central plane.
  • moulding sections of which there are conveniently four in each stick, are preferably secured end to end by an adhesive, and they are accurately positioned with respect to each other whilst the adhesive is setting by means of a jig engaging the winding locating means.
  • the former may be made of aluminium, a metal which has a temperature coefficient of expansion very similar to that of certain types of glass-filled polyester resin. It will be appreciated that a winding formed in the manner described above will not be exactly helical although it will approach a helical configuration if a large number of elongate elements are used in each layer. Using a winding of approximately 1 m in diameter, we have found that an acceptably uniform magnetic field (i.e. varying by no more than plus and minus 10 parts per million) can be obtained by using 48 polyester resin sticks in each layer.
  • winding of a solenoid in accordance with the invention comprises a plurality of layers of turns two or more of the layers may be provided with tappings for the connection of resistive current shunts.
  • a winding may consist of a plurality of conducting elements. These can be bare and in electrical contact so that they constitute, in effect, a single conductor. However it may in some cases be desirable for the elements of a multiple element winding to be connected in series, and in such a case they must, of course, be electrically insulated from each other, as by the provision of insulating coatings.
  • the winding itself is preferably of copper rather than aluminium, since although a copper winding has a lower coefficient of expansion than the supporting polyester sticks and former, it has a lower resistivity than aluminium and therefore requires less cooling than an aluminium winding of comparable size.
  • the winding construction described above has a very open structure and can be cooled by a simple arrangement, for example by enclosing the former and end-cheeks in a cylindrical outer casing and pumping cooling fluid through the resulting enclosure in a uniform flow parallel to the former axis.
  • cooling fluid may be any suitable oil.
  • the solenoid is connected to an auxiliary fluid cooling circuit in parallel with the main cooling circuit, the auxiliary cooling circuit being provided with means such as a variable output pump or fan for controlling its rate of heat removal from the solenoid, so that the temperature of the winding as a whole may be kept constant irrespective of changes in the ambient temperature.
  • the auxiliary cooling circuit being provided with means such as a variable output pump or fan for controlling its rate of heat removal from the solenoid, so that the temperature of the winding as a whole may be kept constant irrespective of changes in the ambient temperature.
  • a temperature sensor may be used to monitor changes in the ambient temperature, and its output connected to a microprocessor which is arranged to control means for varying the rate of heat removal in an appropriate sense to maintain the winding temperature at a constant value.
  • a solenoid for use as a field coil in an N.M.R. spectrometer associated with means for cooling the solenoid is also associated with heating means, arranged to be operative when the spectrometer is not in use in order thereby to reduce the risk of appreciable magnetic field variations due to temperature changes when the spectrometer is brought into operation.
  • the solenoid is connected to a main cooling circuit, and an auxiliary cooling circuit which is provided with means for controlling the rate of heat removal from the solenoid
  • means for heating the fluid in the auxiliary cooling circuit there is also provided means for heating the fluid in the auxiliary cooling circuit.
  • the heating means is arranged to be operative, when the solenoid is not in use, to cause heated fluid at a first temperature T 1 to be circulated through the solenoid casing, and when the solenoid is in use the cooling circuit is arranged to maintain the mean temperature of the fluid within the solenoid casing at a second temperature T 2 , at which temperature the mean temperature of the winding is approximately T 1 .
  • the temperature changes resulting from energisation of the solenoid can be kept to an absolute minimum, thereby minimising fluctuations in the magnetic field.
  • the keeping of the mean temperature of the winding at or near its operating temperature in this way permits the N.M.R. spectrometer to be instantly available for use, i.e. with no warm up period, whilst at the same time keeping the electrical consumption to a minimum.
  • a rigid aluminium former 1 provided with end-cheeks 2 and 3 is mounted for rotation (by means not shown) about its axis.
  • Accurately moulded glass-filled polyester resin sticks 4, aligned parallel to the former axis are accurately located in the axial direction by the end-cheeks 2 and 3.
  • the sticks are rectangular in cross section and are regularly circumferentially spaced about the surface of the former 1 by cylindrical pins 9 (only two of which are shown) which fit into accurately drilled holes in the former 1 and engage appropriately positioned holes in the under surfaces of the sticks.
  • Each stick is provided with a similar set of regularly spaced slots 10 in its outwardly facing surface. Adjacent sets of slots are regularly and successively axially displaced in the direction of the former axis, so that the slots lie in a helical configuration.
  • Each of the sticks 4 is conveniently formed from four separate sections 4a, 4b, 4c, 4d joined together end to end as illustrated in Figure 2.
  • the sections of each stick are formed by moulding, the two inner sections 4b, 4c being formed in the same or identical moulds, as are the two outer sections 4a, 4d.
  • the sections on one side of the central plane are turned longitudinally through 180° with respect to those on the other side so that the two halves of the stick 4 are mirror images of one another.
  • the stick sections are conveniently secured to each other by an adhesive, as at 5, the sections being aligned and located longitudinally with respect to each other whilst the adhesive setting by a jig (not shown) having locating pegs which engage at least some of the slots 10 of the sections being joined. In this way it is ensured that the slots of adjacent sections are accurately located with respect to each other whilst allowing for slight tolerances in the overall lengths of the sections.
  • Conductors 11 and 12 are wound under constant tension onto the helical arrangement of slots from a mandrel 8. Multiple conductors are used in order to ensure flexibility during winding. Any suitable number of conductors may be used, but only two are shown in Figure 1 for the sake of clarity.
  • the conductors are preferably rectangular in cross-section, and fit tightly in the slots 10.
  • Circumferential bands may initially be used to hold the sticks down on the former surface.
  • the conductors may be individually insulated by thin tape (not shown) (e.g. 0.01 mm thick) although this is not always necessary.
  • Sets of spacers (not shown) temporarily inserted between the sticks ensure that the sticks do not bend under the winding strain, and help to provide a greater degree of accuracy in the wound coil.
  • a second layer of sticks such as 6 ( Figure 3) may be fixed directly on top of the sticks of the first layer by means of a free-flowing adhesive.
  • the outwardly facing surfaces of the first layer of sticks serve to accurately radially locate the sticks of the second layer of the winding, the second layer also being located circumferentially by the provision of pips (not shown) the upper surface of the first layer of sticks which fit into appropriately positioned holes in the sticks of the second layer.
  • the sticks of the second layer are slotted at 10' in a precisely similar manner to those of the first, except that the slots form a helix of the opposite sense to the helix in the first layer.
  • a second layer of turns (11', 12') is then wound in this helical configuration of slots and the procedure is repeated to form the requisite number of layers (which should be an even number) and is preferably six, the sticks of each subsequent layer being accurately positioned with respect to the sticks immediately beneath them in the same manner as the sticks of the second layer.
  • the winding is then coated with a thin layer of adhesive and encased in a casing 16 (Figure 3).
  • Figure 3 also shows two of a set of regularly circumferentially spaced oil ducts 17a and 17b pierced in the casing 16. In use, oil is pumped in via the ducts 17a to the spaces 18 between the stacks of polyester resin sticks and out via the ducts 17b.
  • Figure 4 shows in more detail preferred cooling arrangement for the central solenoid 7 of a set of field coils for a medical N.M.R. machine.
  • a high-velocity primary cooling circuit 19 connected between an inlet duct 17a and an outlet duct 17b of the solenoid casing 16 is operated by a pump P 1 only when the solenoid 7 is energised.
  • a low-velocity secondary cooling circuit 20 connected in series with the main cooling circuit 19 is continuously operated by the pump P 2 , even when the solenoid is switched off and passes through a heat exchanger E. The resulting flow of cooling fluid is indicated by the solid arrows.
  • a heater H is associated with the secondary cooling circuit, and is arranged to be energised only when the solenoid is not operating.
  • the cooling circuits are inter-connected on the inlet sides of the pumps P 1 , P 2 as shown by a common non-return valve V.
  • a common non-return valve V When the solenoid is not energised heater H is controlled by temperature probe TP in the inlet duct 17a so as to maintain the temperature of the fluid at the inlet 17a at a temperature T1.
  • the solenoid 7 When the solenoid 7 is energised the heater H is switched off, and the pump P 1 is energised to force cooling fluid at a greater velocity through the solenoid, some of the fluid from outlet duct 17b flowing through the valve V (as indicated by the dashed arrows) and the remainder flowing through heat exchanger E and back into cooling circuit 19 (as indicated by the solid arrows).
  • the temperature of fluid in the inlet duct 17a of the solenoid is monitored by the probe TP which controls the effective rate of operation of a further pump P 3 which feeds a heat exchange fluid through the heat exchanger E and thereby controls the rate at which heat is removed from the cooling fluid by the heat exchanger so as to maintain the temperature of the cooling fluid at the inlet 17a at a temperature such that when the solenoid is energised, the mean temperature of the winding is also T1.
  • the probe TP may be located at the outlet duct 17b.
  • the aluminium former 1 may be replaced by a relatively thin-walled cylinder of a synthetic plastics material, which provides a base for the sticks 4, 6.
  • the cylinder with integral end-cheeks also of plastics material
  • the cylinder with integral end-cheeks is arranged to be supported internally during the winding on of the conductors 11, 12.
  • an outer cylinder also of plastics material
  • a solidifiable insulating material bondable to the inner and outer cylinders is introduced into the space between them to impregnate and enclose the winding.
  • the internal support can be removed, as the assembly is then in the form of a rigid structure.
  • Cooling may be achieved, either by making the sticks 4, 6 over which the conductors are wound hollow and connecting their ends to manifolds for the passage of the cooling fluid, or alternatively introducing additional tubular members between the sticks for such a purpose.
  • the winding conductors can themselves be of tubular form and arranged to carry the cooling fluid.
  • the central solenoid 7 will be located coaxially between two end coils 22 ( Figure 5).
  • each of the end coils 22 is supported by a mounting which permits the coil axis to be moved transversely and tilted in any direction to a limited extent, as well as enabling the spacing between the coil and the adjacent end of the solenoid 7 to be varied.
  • Means are provided for securing a coil in any set position.
  • the parts of the current leads 23 adjoining the solenoid 7 and the two end coils 22 are disposed substantially in the same axial plane and at the corresponding ends of the three members.
  • shimming resistors 24 may be connected between tappings as at 25 on one or more of the winding layers of the solenoid.
  • a shimming resistance can be connected across the whole or only part of a winding layer as may be required.
  • a temperature sensitive element may be located so as to be responsive to changes in the temperature of the solenoid, and arranged to control the solenoid current in the sense which maintains the field strength of the solenoid approximately constant despite such changes, at least over a predetermined temperature range. For example an increase in the temperature of the solenoid will lead to an expansion thereof with a consequent reduction in the field strength.
  • the solenoid current is normally provided by a rectifier circuit controlled by a resistor arranged to be maintained at a constant temperature.
  • the rectifier control circuit resistor has a suitable negative temperature coefficient of resistance and is located so as to be responsive to the temperature of the solenoid cooling fluid either within, or as it leaves, the solenoid, it can be arranged to increase the solenoid current as the temperature rises and reduce it as the temperature decreases so as to compensate for expansion or contraction of the solenoid due to such temperature changes, and thereby maintain the field strength substantially constant.
  • a resistor with zero temperature coefficient of resistance supplying the rectifier control circuit with a first voltage signal and a second resistor having either a positive or a negative temperature coefficient of resistance arranged to supply the rectifier circuit with another signal which could then be added or subtracted from the first signal to provide a control signal which keeps the rectifier current constant when the solenoid temperature is constant, but increases or decreases the rectifier current when the solenoid temperature increases or decreases.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Electromagnets (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)
EP19840302366 1983-04-08 1984-04-06 Electrical winding Expired EP0122133B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB838309558A GB8309558D0 (en) 1983-04-08 1983-04-08 Electrical windings
GB8309558 1983-04-08

Publications (2)

Publication Number Publication Date
EP0122133A1 EP0122133A1 (en) 1984-10-17
EP0122133B1 true EP0122133B1 (en) 1987-07-08

Family

ID=10540807

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19840302366 Expired EP0122133B1 (en) 1983-04-08 1984-04-06 Electrical winding

Country Status (5)

Country Link
EP (1) EP0122133B1 (ja)
JP (1) JPS59206750A (ja)
CA (1) CA1236526A (ja)
DE (1) DE3464667D1 (ja)
GB (2) GB8309558D0 (ja)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102906587A (zh) * 2010-05-26 2013-01-30 英国西门子公司 由多个轴向对准的线圈组成的螺线管磁体

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4509030A (en) * 1984-07-05 1985-04-02 General Electric Company Correction coil assembly for NMR magnets
US4500860A (en) * 1984-07-05 1985-02-19 General Electric Company Winding support and method for NMR magnet axisymmetric correction coils
DE3613682A1 (de) * 1986-04-23 1987-10-29 Bruker Analytische Messtechnik Verfahren und vorrichtung zum kuehlen eines resistiven magnetsystems fuer kernspintomographen
KR970009131B1 (ko) * 1987-01-20 1997-06-05 코니카 가부시끼가이샤 사진 필름용 스풀
JPH07118410B2 (ja) * 1987-05-26 1995-12-18 株式会社東芝 超電導コイル装置
FR2618016A1 (fr) * 1987-07-10 1989-01-13 Thomson Cgr Dispositif de refroidissement d'un aimant resistif
CH675791A5 (ja) * 1988-02-12 1990-10-31 Sulzer Ag
JP2752156B2 (ja) * 1989-05-30 1998-05-18 株式会社東芝 Ｍｒｉ装置用コイル部品の製造方法
DE19640981A1 (de) * 1996-10-04 1998-04-16 Asea Brown Boveri Rogowskispule
DE102005020106A1 (de) * 2005-04-25 2006-10-26 Bombardier Transportation Gmbh Elektromagnet, insbesondere für ein Zugsicherungssystem, und Verfahren zu dessen Herstellung
DE112006003946B4 (de) * 2006-12-20 2017-10-26 SUMIDA Components & Modules GmbH Induktives Bauteil mit einem Spulenkörper mit integrierter Wicklung
FR2939827B1 (fr) * 2008-12-15 2011-01-07 Adler Sas Verrou electromagnetique.
JP2011204836A (ja) * 2010-03-25 2011-10-13 Toyota Motor Corp コイルユニット、非接触電力受電装置、非接触電力送電装置、および車両
GB2488328B (en) * 2011-02-23 2014-04-09 Siemens Plc Superconducting electromagnets comprising coils bonded to a support structure
US9480415B2 (en) 2013-04-26 2016-11-01 Medtronic Navigation, Inc. Electromagnetic coil apparatuses for surgical navigation and corresponding methods
RU2577322C2 (ru) * 2014-06-05 2016-03-20 Открытое акционерное общество "Омский научно-исследовательский институт приборостроения" (ОАО "ОНИИП") Способ изготовления катушек индуктивности
US11096605B2 (en) 2015-03-31 2021-08-24 Medtronic Navigation, Inc. Modular coil assembly
JP6607809B2 (ja) * 2016-03-10 2019-11-20 株式会社ダイヘン コイルボビン、コイル及びそのコイルを備えた変圧器
CN113708737A (zh) * 2020-05-22 2021-11-26 恩智浦美国有限公司 电感器组合件、阻抗匹配网络及包括电感器组合件的系统

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB147697A (en) * 1917-10-24 1921-06-23 Drahtlose Telegraphie Gmbh Improvements in conducting coils
GB228267A (en) * 1923-11-01 1925-02-02 Ernest Charles Washington Evan Improvements in electric inductance coils and in formers therefor
US1647615A (en) * 1924-02-07 1927-11-01 Western Electric Co Electrical coil
GB246158A (en) * 1925-01-16 1926-07-01 Westinghouse Electric & Mfg Co Improvements in or relating to electrical inductances
US1608673A (en) * 1925-04-20 1926-11-30 Edward J Schroder Radiocoil
GB274160A (en) * 1926-03-19 1927-07-19 Benjamin Hesketh Improvements in and relating to electrical inductances
GB303541A (en) * 1927-10-04 1929-01-04 Frederick William Twort Improvements relating to electrical transformers or couplers
GB315487A (en) * 1928-04-19 1929-07-18 Thomas Alfred Biddington Improvements in or relating to wireless receiving apparatus
GB326859A (en) * 1928-11-22 1930-03-24 Harold Randall Hayden Improvements in thermionic valve circuits
GB326190A (en) * 1928-12-06 1930-03-06 H W Sullivan Ltd Improvements in or relating to inductance coils
GB329841A (en) * 1929-05-18 1930-05-29 Thomas Alfred Biddington Improvements in or relating to wireless receiving apparatus
US1929187A (en) * 1930-09-24 1933-10-03 Exolon Company Water and air cooled electromagnet
US1876670A (en) * 1932-04-25 1932-09-13 Heintz & Kaufman Ltd Inductance coil
FR931802A (fr) * 1946-08-06 1948-03-04 Radioelectriques Lab Support réglable pour enroulements hélicoïdaux, notamment pour bobines de self-induction
GB624994A (en) * 1947-07-23 1949-06-20 Gen Electric Co Ltd Improvements in or relating to electric contact arrangements for relatively movable conductors
US2795765A (en) * 1952-10-31 1957-06-11 Joe A Stroble Inductor form
GB866952A (en) * 1958-09-27 1961-05-03 Cole E K Ltd Improvements in or relating to inductance coils
DE1206500B (de) * 1964-03-26 1965-12-09 Telefunken Patent Wickelkoerper fuer Hochfrequenztransformator
FR2509904B1 (fr) * 1981-07-20 1985-12-27 Legrand Sa Cale de bobinage

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102906587A (zh) * 2010-05-26 2013-01-30 英国西门子公司 由多个轴向对准的线圈组成的螺线管磁体
CN102906587B (zh) * 2010-05-26 2016-05-04 英国西门子公司 由多个轴向对准的线圈组成的螺线管磁体

Also Published As

Publication number Publication date
CA1236526A (en) 1988-05-10
GB8408916D0 (en) 1984-05-16
GB2139003A (en) 1984-10-31
GB2139003B (en) 1987-07-15
GB8309558D0 (en) 1983-05-11
EP0122133A1 (en) 1984-10-17
DE3464667D1 (en) 1987-08-13
JPS59206750A (ja) 1984-11-22

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