DE2541871A1 - Communication transformer with low leakage inductance - has primary and secondary windings made from strip cable with thermoplastic interleaving - Google Patents

Abstract

A communication transformed has a very low leakage inductance and is used in a transmission networks operating at above 10 kHz. The transformer is designed with a ferrite or a slit core. The primary and secondary windings are made up of flat strip cable (4) wound around a former (2) with rectangular cross section and rectangular end flanges. The width of the flat cable is equal to the width of the winding. There are several turns of the flat cable to produce the equivalent number of layers. The conductors in the cable are parallel and inserted between two foils with thermoplastic covering. This reduces the stray inductance.

Description

transmitter

The invention relates to a transmitter, in particular for frequencies greater than 10 kHz, which can be used for higher-frequency electronic power supplies is.

The one placed on the usual network transformers with 50 to 60 Hz network frequency The most important requirements are the galvanic isolation of the mains load circuit, a Voltage ratio according to the voltages required in the load circuits, the coupling of current ratios with voltage ratios and, as a rule the secondary-side insertion of control circuits, both voltage changes of the network and the load side.

For transmitters that are above the mains frequency, e.g. at 10 kHz and higher, work will also be the fulfillment of the aforementioned requirements strived for. The higher the frequency offered, the smaller it can be in terms of volume in this case, the transformer can be designed with the same transmitted power. Up there the network side for converting the network frequency into the working frequency oscillating circuits are necessary, the oscillating circuits are generally used in these transmitters used for regulation.

A comparison of the usual network transmitters and transmitters that The demands made to work above the mains frequency show that the latter Transformers enable significant technical and economic advantages. To their Implementation, the following considerations must be taken into account: The working frequency 'should be as high as possible, whereby - the electric ones Data of the circuit components, e.g.

for oscillation, rectifier and control circuits to be taken into account are.

The transformer core should have low losses, i.e. they are ferrite cores or to use tape cores in certain cases.

The winding structure is to be chosen so that the capacities between The windings are kept small to avoid interference voltages that are coupled into the circuits should be kept as low as possible.

To keep the coupling of the windings as high as possible bring, the leakage inductance should be small.

As is known per se, the transformer must be used as a flyback converter have an air gap in order to achieve the greatest possible power for a given induction to be able to transfer. The air gap here has a reduction in the effective permeability result.

Since for manufacturing reasons, the air gap within the Spulenwickeis or inside or outside of the bobbin comes to lie, must care must be taken to ensure that the winding voltages are corrected by means of appropriate winding arrangements remain the same to each other and the copper eddy current losses in the vicinity of the air gap don't get too big.

Finally, regulating windings are used to control the regulating circuits provided with those secondary windings that allow an alternating flow of current are subject to, are to be closely coupled.

The present invention is based on the object of a low-leakage inductance Transmitter, especially for frequencies greater than 10 kliz, with a ferrite or cut ribbon core to create that meets the requirements listed above.

To solve this problem, the invention provides that all windings of the transfer device are designed as ribbon cables.

In the case of ribbon cables, the capacitance between adjacent, e.g. Wire-shaped single cores determined and therefore a construction element. Leave it through nesting, stacking, skipping turns all required leakage inductance values can be calculated immediately in one strip line, Achieve linkages and capacity values. Also certain winding voltages can be implemented in this way. It is possible by cascading of the individual wires on a printed circuit board, the number of turns or through Parallel connection to increase the effective conductor cross-sections. Besides, let spatially between parallel-connected conductors of another system insert. These transformers have a relatively small number of turns with complicated ones Winding structures necessary. Since for these reasons a machine winding like in the case of network transmitters, becomes uneconomical through the use of these Eandleitung a much more economical production possible.

Can be used as ribbon cables that are parallel to each other and more or less spaced round or flat, e.g. wire-shaped, conductors between two foils coated with thermoplastic material are embedded. As ribbon cables can also have enameled wires that are parallel to one another and more or less spaced apart thermoplastic overlay can be provided, the dielectric strength being achieved by the lacquer insulation is increased. The enameled wires can be at least partially in an adhesive or lacquer be embedded.

Also the embedding of the wires in a plastic film coated on one side or the arrangement of the enameled wires between two adhesive tapes is advantageous.

The Erxindang is explained in more detail below with reference to the drawing.

The figures show: FIG. 1 a wound bobbin according to the invention in a schematic and perspective illustration, Figure r one for a transformer 1 used winding with at right angles to the winding longitudinal direction The beginning of the winding and the end of the winding, FIGS. 3 to 6 each show an exemplary embodiment in an end view a 3andleitung according to the invention.

In the following, the structure of a for Higher frequencies suitable transformer with two ribbon lines described. For the primary winding and the first secondary winding of the transformer 1 is here a ribbon line of the type shown in Figure 3 to 6 with z. B. 30 ladders used, wherein the width of the ribbon line is preferably equal to the winding width.

This ribbon cable is wound around the bobbin 2 six times.

By connecting two parallel conductors in series twelve times 5 the number of primary turns n1 is 12 x 6 = 72 turns (24 conductors). the the remaining six conductors are connected in parallel to increase the cross-section. The number of turns n2 = 6 turns corresponds to the six wraps of the Ribbon line 4 around the bobbin 2.

To ensure a good coupling to one another, the line separated several times. This results in a good interleaving of primary and Secondary winding.

The second ribbon line with two turns consists of seven, for example Enamelled copper wires and a specially insulated conductor. The management is here on the top and bottom with adhesive tape haltext.

By connecting one three in parallel, the other four Eupferlack wires result in two further secondary windings of the same voltage and different Power output. The insulated conductor represents the control winding additional insulation is necessary because the control circuit has mains potential. About voltage increases due to changes in the load on these two secondary windings, the control winding is not distorted forward, they are nested around the control winding.

The beginning and end of the winding are as shown in FIG is led out of the coil without soldering lugs and directly with a not shown PCB contactable.

Wires, if necessary, are used as conductors for the ribbon cables Enamelled copper wires, with the same or different diameter or, if this is due to the dielectric strength is required, better insulated conductors are used. The ladder will be required in The number and length are parallel and preferably closely spaced from one another and e.g. according to Figure 3 between two adhesive tapes 6 or a folded adhesive tape inserted or optionally between two with thermoplastic material coated foils embedded. According to FIG. 4, the wires 5 can also be used as a carrier serve a plastic film 7, which carries a coating 8, in which the conductor 5 are embedded.

If enamelled wires are used, as shown in Figure 5, be at least partially embedded in an adhesive or lacquer 9.

Finally, the ribbon line according to FIG. 6 shows parallel to one another and spaced-apart Lackdra.hte 5, which with a thermopraw elastic support are coated.

8 claims 6 figures

Claims (8)

P a t ~ en t a n s ~ Er ii c h e Low-leakage inductance transformer, especially for frequencies greater than 10 kiiz, with a Berrit or cut core, d ad u r c h g e k e n n n z e i c h n e t that the windings are designed as ribbon cables are. 2. Transmitter according to claim 1, d a d u r c h g e k e n n z e i c hn e t that parallel and spaced wires are provided as ribbon lines are embedded between two foils coated with thermoplastic material are. 3. Transmitter according to claim 1, d a d u r c h g e k e n n z e i c n e t that as ribbon lines parallel and spaced enamelled wires with one another thermoplastic support are provided. 4. Transmitter according to claim 1, d a d u r c h g e k e n n z e i c hn e t that parallel and spaced enamelled wires are provided as ribbon cables that are at least partially embedded in an adhesive or varnish. 5. Transformer according to claim 4, d a d u r c h g e k e n n z e i c nn e t that the enameled wires are arranged between adhesive tapes, 6. Transformer according to claim 1, that as ribbon lines mutually parallel and spaced wires are provided, which in a unilateral coated plastic film are embedded. 7. Transmitter according to claim 1 and at least one of the claims 2 to 6, that is, the beginning and end of the lap Lead out of the coil without soldering lugs and directly to a circuit board are contactable. 8. Transmitter according to claim 1, d a d u r c h g e k e n n: e i c hn e t that the windings and possibly the conductors of the windings accordingly nested the desired magnetic and electrical values of the transformer or are interconnected.