Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
  • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
  • H01F41/0206—Manufacturing of magnetic cores by mechanical means
  • H01F41/0213—Manufacturing of magnetic circuits made from strip(s) or ribbon(s)
  • H01F41/022—Manufacturing of magnetic circuits made from strip(s) or ribbon(s) by winding the strips or ribbons around a coil
• • 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
  • H01F27/26—Fastening parts of the core together; Fastening or mounting the core on casing or support
  • H01F27/266—Fastening or mounting the core on casing or support
• • 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
  • H01F27/28—Coils; Windings; Conductive connections
  • H01F27/2847—Sheets; Strips
• • 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
  • H01F27/28—Coils; Windings; Conductive connections
  • H01F27/2847—Sheets; Strips
  • H01F27/2852—Construction of conductive connections, of leads
• • 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
  • H01F27/28—Coils; Windings; Conductive connections
  • H01F27/30—Fastening or clamping coils, windings, or parts thereof together; Fastening or mounting coils or windings on core, casing, or other support
  • H01F27/306—Fastening or mounting coils or windings on core, casing or other support
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F30/00—Fixed transformers not covered by group H01F19/00
  • H01F30/06—Fixed transformers not covered by group H01F19/00 characterised by the structure
  • H01F30/16—Toroidal transformers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
  • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
• • 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
  • H01F27/28—Coils; Windings; Conductive connections
  • H01F27/2847—Sheets; Strips
  • H01F2027/2857—Coil formed from wound foil conductor
• • 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
  • H01F27/28—Coils; Windings; Conductive connections
  • H01F27/2847—Sheets; Strips
  • H01F2027/2861—Coil formed by folding a blank

Definitions

• the present invention relates to a transformer, and especially a thin toroidal type transformer.
• Transformers of this type consist of an O-ring of magnetic material around which are arranged one or more primary windings and one or more secondary windings.
• the windings are made around a carcass, made of an insulating material, generally in two parts, arranged around the torus, on which one comes to wind an insulated conductive wire, of section appropriate to the intensity of the current it is intended to deliver.
• This type of transformer is difficult to manufacture due to the problems posed by the production of the series of windings around the toroid.
• the windings are usually made by automatic machines, but these machines, in addition to their complexity and their high cost price, are difficult to use for windings of large diameter wires.
• these machines require a relatively large center opening of the torus. This is why it has been proposed to produce the toroid in two parts, in the form of a C, on which the primary and secondary windings are threaded. previously wound on insulating carcasses. The two C-shaped parts are then assembled so as to reconstitute the torus. Transformers are thus obtained whose manufacturing cost is reduced substantially, but which have an air gap causing magnetic losses causing their efficiency to drop significantly.
• the present invention aims to simplify the manufacture of high efficiency toroidal transformers, provided with a secondary intended to be traversed by currents of high intensity, and having various outputs allowing to have multiple operating voltages.
• the present invention relates to a toroidal type transformer comprising a ring-shaped magnetic circuit consisting of a series of windings of a strip of magnetic sheet metal, around which are arranged at least one primary winding and at least one winding. secondary, characterized in that each of the primary windings and secondary is disposed around a carcass of insulating material, surrounding the ring, this carcass being provided on its internal face with guide means intended to come into contact with the internal face of the strip constituting the ring.
• Figure 1 is a top view in partial section of a transformer according to the invention.
• Figure 2 is a perspective view of a foldable element intended to constitute a winding carcass.
• FIG. 3 is a perspective view of a winding carcass made up of the foldable element of FIG. 2.
• Figures 4a, 4b and 4c show details of implementation of a winding carcass according to the invention.
• FIG. 5 is a perspective view of an embodiment of a transformer secondary according to the invention.
• Figures 6 and 6a are two views in partial section, along the line VI-VI of Figure 1, of two variants of a winding carcass.
• Figure 7 is a plan view of an element constituting the secondary winding.
• Figure 8 is a partial top view of several elements shown in Figure 7 once assembled.
• Figure 9 is a cross-sectional and vertical view of an electrical connection mode of a conductive wire on the secondary of the transformer.
• FIG. 10 is a perspective view of a detail of embodiment of FIG. 9.
• FIGS. 1 to 4 a toroidal transformer 1 essentially consists of a magnetic circuit of substantially toroidal shape 3, a primary comprising two windings 5.5 ′ and a secondary comprising two windings 7.7 ′.
• the magnetic circuit 3 consists of a strip 4 of magnetic material, such as for example a sheet of silicon, wound on itself so as to constitute a ring.
• the two primary windings 5.5 ′ each consist of a carcass 9, made of an insulating material, such as a plastic material, on which are wound turns 11 of conductive wires provided, on their periphery, with an electrical insulator .
• the carcass 9 is in the form of a parallelepipedal box open on two of its opposite faces 10,10 'and the distance between its two main walls 15,17 parallel to the plane of the circuit magnetic 3 is slightly greater than the height thereof, so that the housing 9 can surround the magnetic circuit.
• the two windings 5.5 ′, as shown in FIG. 1, are arranged symmetrically with respect to a plane passing through the center of the ring 3.
• the housing 9 is obtained by folding an element 9 ′, manufactured by molding, and having, as shown in FIG. 2, at the location of the folds, recesses 13 in the form of a V.
• Two of the faces 15 and 17 of this element 9 ′ which, after folding, will respectively constitute the lower and upper main walls of the housing 9, are provided with a boss of rectangular cross section 19,19 ′ and in the form of an arc of a circle of radius r, of the same order of magnitude as the internal radius of the magnetic circuit 3.
• the two bosses 19, 19 ', before the folding of the element 9' have their respective concavities oriented one opposite the other, so that, after folding, the two circular bosses 19, 19 ′ are superimposed.
• rollers 27 comprise two end studs 29 and a cylindrical central part 31 whose diameter is such that when the two studs 29 are in place in the holes 21, 23, the central part 31 of the roller 27 protrudes towards the inside of the carcass 9 the bosses 19.19 '.
• the windings 7, 7 'constituting the secondary are arranged diametrically opposite along an axis xx' perpendicular to the axis zz 'of the two primary windings.
• the transformer secondary consists of massive elements, connected to each other so as to obtain electrical continuity.
• each element thus consists of a rectangular plate 35 provided with a rectangular central recess 37, the length and width of which correspond respectively to the width and to the height of the housing 9.
• Each of the plates 35 comprises a transverse notch 41 connecting the central recess 37 to the outside and making it possible to fold the upper part 43 of a plate on one side and the lower part 45 of this same plate on the other side, so as to join the upper part 43 of a given plate to the lower part 45 of an adjacent plate.
• the connection between the plates 35 can be achieved for example by welding and all of the plates 35 thus constitutes a winding.
• the secondary of the transformer is thus constituted, in the present embodiment, of two identical windings 7 and 7 'joined by a conductive plate 8.
• the length of the conductive plate 8 is substantially of the same value as that of the carcasses 9, so that each winding constituting the transformer secondary may be around the magnetic circuit 3, diametrically opposite along an axis xx 'perpendicular to the axis zz' of the two primary windings.
• the various constituent elements of the latter take place in a housing 50, and the external ends 51 of the plates 35 constituting the secondary of the transformer are kept at a given distance from each other by an insulating element 52 provided with vertical slots, inside which take place each of the external ends 51 of the plates 35.
• the two windings 7,7 'constituting the secondary of the transformer can be produced by one piece, for example by molding. This latter mode of implementation being particularly advantageous as regards the cost price of the transformer.
• the plates 35 constituting the secondary are not coated with insulator, the dielectric being constituted, in the present case by air, and the distance e separating two adjacent plates 35 will be determined in a known manner according to of the tension between them.
• the embodiment of the secondary according to the invention makes it possible to carry out, in a simple manner, multiple mid-points, or points of sampling of multiple tensions, by simply extending towards the outside of the transformer the plates 35 of a length making it possible to make an electrical connection.
• FIGS. 9 and 10 It is possible, for example, as shown in FIGS. 9 and 10, to use means for clamping the conducting wires 80 which are self-locking.
• These means consist of a clamping nut 70 traversed by a central threaded hole 72 and comprising a slot transverse 76 extending, in the direction of the axis of the hole 72, over a part of the thickness of the nut 70, so as to give it a certain flexibility.
• the base of the nut 70 is hollowed out by two transverse grooves 78 of thickness less than the diameter of the electric cables 80 to be connected to the transformer.
• a screw 84 on which a tightening washer 86 is threaded passes through a slot 88 provided on the edge 51 of the plate 35 and is screwed into the threaded hole 72 of the clamping nut 70.
• the conducting wires 80 intended to ensure the electrical connection of an installation with the transformer, take place in the grooves 78, existing between the clamping nut 70 and the plate 35.
• the screw 84 is tightened the conducting wires 80 being thicker than the depth of the groove 78 the bottom of the nut 70 is not in contact with the plate 35 and, during tightening, the two parts of the nut 70 located on either side of the transverse groove 76 deform and tighten against the screw 84, thereby braking the latter and preventing any accidental unscrewing.
• the guide means can consist of simple circular bosses 20, 20 ′ provided inside the upper 17 and lower 15 faces of the housing 9.
• Element 9 ′ shown in FIG. 2, is used for this, on which the pins 29 of the guide rollers 27 are placed in the holes 21 provided in the circular boss 19, and the part 17 of said element is folded back.
• the holes 23 in the bosses 19' take their place around the opposite stud 29 'of the rollers 27, the chamfers 25 at 120 ° provided in the holes 23 allowing the part 17 to be folded down.
• the strip 4 Before its installation, the strip 4 is wound on a hub of radius r equal to the interior radius of the magnetic circuit of the transformer, then it is annealed at around 800 ° C. After this annealing operation, the strip is ready to be placed inside the housings 9.
• FIG. 11 which consists of the stand 81 receiving a hub 82, movable in rotation about a central axis, on which is wound the magnetic strip 4 previously annealed, and which one wishes to introduce in the four housings 9, and a drive system composed of four rollers A, B, C, D one of which, the roller A, can be rotated in the direction of the arrow F by a motor, not shown in the drawing, and another, the roller D, is movable in translation under the action of elastic means 90.
• a thin and flexible driving strap 92, or a belt, is introduced inside the three upper casings 9, namely the housings 9a, b, c, and is wound against the four rollers C, D, A, B , this strip being fixed on itself, by means not shown in the drawing, so as to constitute an endless loop maintained under tension by the tensioner roller D under the action of the tension spring 90.
• the radius of the hub 82 is close to the outside radius r ′ of the magnetic circuit 3 once it is finished.
• toroidal type transformers using a primary winding and a secondary winding superposed and, in this case, in order to facilitate the positioning of the magnetic strip inside the windings, three additional housings are used 9 , arranged as above, and intended to guide the strip during its installation.
• the three additional boxes 9 are removed after the positioning in the primary and secondary of the forming hole of the magnetic strip 4.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Coils Or Transformers For Communication (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9392552

Family Applications (1)

Country Status (3)

Families Citing this family (4)

Citations (14)

• 1990
  • 1990-01-05 FR FR9000097A patent/FR2656951A1/fr active Granted
  • 1990-12-24 EP EP90403761A patent/EP0436434A1/fr not_active Withdrawn
  • 1990-12-24 WO PCT/FR1990/000942 patent/WO1991010244A1/fr unknown

Patent Citations (14)

Non-Patent Citations (4)

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