EP0122546B1 - Flyback transformer - Google Patents

Description

The invention is based on a line transformer with a winding made of a metallic foil and an intermediate plastic foil serving as insulation, the winding taps consisting of electrically conductive molded parts inserted transversely to the winding or welded onto the metal foil and protruding beyond the foil edges.

To simplify and reduce the cost of producing a winding for a line transformer, it is known to produce the winding with the aid of a metallic film, a plastic film insert serving as insulation. The individual electrical taps of the winding are produced by wires or molded parts which are inserted and wrapped transversely to the winding or which are welded onto the metallic foil and which project beyond the edge of the foil (DE-AS 2 612 465). As a result, a significantly smaller winding space is required than with wire windings.

So-called diode split line transformers are known which consist of a first winding which carries the primary winding and the secondary windings and which have a second winding from which the high voltage is taken. The high-voltage winding consists of several winding chambers into which the high-voltage winding is distributed. The individual winding sections in the chambers are connected in series via diodes. The high-voltage winding is embedded in a synthetic resin to achieve sufficient high-voltage strength. A sufficiently large coupling between the windings is necessary, i.e. the winding space is very limited in such transformers for the first-mentioned winding. Since the primary winding of the first winding has a relatively high number of turns, this primary winding using film technology takes up too much winding space.

Task and solution

The invention is therefore based on the object of finding a space-saving winding technique for a diode split transformer.

This object is achieved by the measure specified in the characterizing part of the patent claim.

The invention will be explained in more detail using an exemplary embodiment with the aid of the drawing.

1 denotes the winding body of the first winding, on which the secondary winding, consisting of metal foils 2 and insulating intermediate layers 3, is arranged in a known winding technique. At those points of the winding at which taps are led out, metallic molded parts 4 are welded on transversely to the film direction, the ends of which protrude beyond the film edges. A primary winding consisting of copper wire turns 5 is wound on this foil winding. The winding body 6 for the high-voltage winding can be pushed over this winding. According to the invention, for the purpose of returning the wire end 11 of the winding 5, an electrically conductive molded part 7 is inserted in an insulating film layer 8, embedded between the two windings 3 and 5, which protrudes from both ends of the winding. The section of the molded part 7 opposite the connection side 9 is connected to the wire end 10 of the winding 5, so that both ends 9, 10 of this winding lie on a side common to the other connections. This results in a simple return, which is not bulky and thus saves space, since an additional molded part included in the winding does not increase the diameter of a winding, e.g. a return of the wire end outside the winding.

Claims (1)

1. A line transformer having a winding of a metallic foil (2) and an interposed plastic film (3) serving as insulation, wherein the winding taps consist of electrically conducting shaped parts (4) which are inserted transversely to ther winding or welded onto the metal foil (2) and project beyond the edges of the foil, characterised in that the part of the winding consisting of the metallic foil (2) serves, with its taps, as a secondary winding and that the primary winding (5) of the line transformer consists of wire turns and that a further electrically conducting shaped part (7), which projects beyond the winding at both ends, is introduced in the axial direction of the winding between the foil winding (2) and the wire winding (5) with the inclusion of an insulating sheet (8), and that the one extremity (9) of the further shaped part (7) serves as an electrical connection for the end (11) of the wire of the primary (5), which end is connected, in an electrically conducting manner, to the further shaped part (7) at the end opposite to the electrical connection (9).

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