EP1085536B1 - Transformer - Google Patents

Description

The invention relates to an electrical transformer according to the preamble of claim 1.

For voltage equalization between different electrical networks Motor vehicle, an electrical transformer is required, which if possible small construction volume is inexpensive to manufacture.

FR 2 647 253 is an electrical transformer known in which the electrical conductor of a first substrate stand away and with the help of a second substrate to transformer windings get connected. Using those printed on the substrates Conductor tracks and the electrical conductor protruding from the first substrate becomes a ferromagnetic transformer core completely with metallic conductors enclosed.

According to US Pat. No. 4,536,733, an electrical transformer is known, the Ferrite core of shell-like shape arranged on a substrate Metal strip is enclosed. Again, complete the on the substrate printed conductor tracks the metallic enclosure of the ferrite core.

The invention has for its object a generic transformer Manufacture in a compact and integrated design. It is said to have high performance be operable, have a high efficiency, inexpensive to produce and the transformer is said to be used in modern motor vehicles occurring high currents work and can be cooled easily.

This object is in connection with the preamble of claim 1 According to the invention by the characterizing features of claim 1 solved.

This has the advantage that a circuit arrangement for operating the Transformer is arranged. Furthermore, to further reduce the Size and manufacturing costs provided that at least one of the used substrates multi-layer, in particular can be loaded on both sides, is executed.

The conductors can be soldered, welded or through to the substrates simple plug or press connections can be attached in the substrates. The transformer according to the invention can on a commercially available Circuit board, which serves as a substrate, are executed.

To simplify production, it can be provided that the further substrate conical holes for receiving on the side facing the first substrate and centering the ends of the conductors when mechanically plugging the Arrangement. This avoids errors when the plug is inserted automatically further substrate due to bent or not exactly perpendicular from that first substrate of standing conductor.

When contacting with plug or press contacts are resilient contacts from the conductor tracks of the further substrate into the holes or parts thereof ushered. By plugging and then pressing on the other In this case, the substrate is in contact with the protruding conductors of the manufactured the first substrate.

In one embodiment of the invention it is provided that the at least one The core of a circular ring is that the electrical conductor has the core inside and surrounded on the outside like a shell and that the conductors to the transformer windings are connected. It can be provided that the electrical conductor as Sheet metal strips adapted to the core shape are executed. So can the core is almost completely made of conductor material, even with a few windings be surrounded. The connecting conductor tracks can be on the substrates to be designed accordingly wide, so that the core also on the deck sides is completely surrounded by the transformer windings, resulting in little Leakage inductances result.

To further reduce the overall height can be in a next design the invention provide that several cores surrounded by conductors the substrate are connected to form a single transformer.

In order to improve the thermal properties, the Invention provided that the substrate made of thermally conductive ceramic welded copper sheet (direct copper bonding). By the very good heat conduction of this material will result in high transformer performance allows. It can be used to cool the transformer and the surrounding area Power circuits can be provided that the substrate on a heat sink is glued on.

Fig. 1 einen erfindungsgemäßen Transformator in geschnittener Seitenansicht,

Fig. 2 einen schematisch dargestellten erfindungsgemäßen Transformator in Draufsicht und

Fig. 3 Schemaskizze einer Schaltung von mehreren Transformatorkernen zu einem Transformator.

Exemplary embodiments of the invention are shown in the drawing using several figures and are explained in more detail in the following description. It shows:

1 shows a transformer according to the invention in a sectional side view,

Fig. 2 shows a schematically illustrated transformer according to the invention in plan view and

Fig. 3 schematic diagram of a circuit of several transformer cores to a transformer.

Identical parts are provided with the same reference symbols in the figures.

1 shows an annular one arranged between two substrates 1 and 2 Ferrite core 3, which contacted from between the substrates 1 and 2, the Transformer windings forming conductor plates 4 is surrounded. The conductor plates 4 are connected to the substrates 1 and 2 by conductor tracks 5 Transformer windings interconnected. Located next to the transformer itself other components 6 for controlling the transformer Substrates 1 and 2. To remove heat, the bottom 2 of the substrates is open glued to a cooling element 7.

Fig. 2 shows the same transformer schematically in plan view. The representation is enlarged compared to Fig. 1. The current direction in the conductor plates is with Dot and cross symbols indicated. On the right is the primary and on the left the secondary winding.

In Fig. 3 it is shown how a number of toroidal cores 32, 33, 34 to form a single transformer can be used. This way also very flat cores to a powerful transformer put together.

Claims (7)

1. Electrical transformer having at least one core, composed in particular of ferrite, having at least one primary winding and having at least one secondary winding, the at least one core (3) being arranged between electrical conductors (4), which project from a substrate (2), in particular a printed circuit board, and the ends of the projecting conductors (4) being electrically connected to form the transformer windings, and a further substrate (1) being arranged and the ends of the projecting conductors (4) being connected by conductor tracks (5) on the further substrate (1), the at least one core (3) being arranged between the two substrates (1, 2), characterized in that the further substrate (1) is arranged parallel to the first substrate (2), and in that at least one of the substrates (1) used is embodied in a multilayer manner, in particular such that it can be populated on two sides, a circuit arrangement for operating the transformer also being arranged on the substrate (1, 2).
2. Transformer according to Claim 1, characterized in that, on the side facing the first substrate, the further substrate has conical holes for receiving and centring the conductor ends during mechanical mating of the arrangement.
3. Transformer according to one of the preceding claims, characterized in that the at least one core (3) is a circular ring, in that the electrical conductors (4) surround the core on the inside and on the outside in a shell-like manner, and in that the conductors (4) are connected to form the transformer windings.
4. Transformer according to one of the preceding claims, characterized in that the electrical conductors (4) are embodied as lamination strips matched in a shell-shaped manner to the core form.
5. Transformer according to one of the preceding claims, characterized in that a plurality of cores (31, 32, 33) surrounded by conductors (4) on the substrate are connected together to form a single transformer.
6. Transformer according to one of the preceding claims, characterized in that the substrate (2) is composed of copper sheet welded onto thermally conductive ceramic (direct copper bonding).
7. Transformer according to one of the preceding claims, characterized in that the substrate (2) is adhesively bonded onto a heat sink (7).

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